Precaution on Operation - CARiD · automotive oscilloscope and automotive ignition waveform....

LAUNCH X431 PAD Scopebox User’s Manual

Precaution on Operation

The appliance is a sophisticated electronic device, never have it clashed when in use.

Main unit screen may flash at the moment of engine ignition, which is normal.

You may unplug the main unit if the program can not be actuated or confused screen occurs. Plug again to continue the operation.

Make sure the appliance is properly connected to the DLC to avoid communication interruptions.

During operation, keep the screen upward and leveled. Be careful when plugging and unplugging the main cable and diagnostic

connector. Tighten the screw before operation to avoid unexpected disconnecting and/or damage to the port.

Handle with care. Avoid collision. Unplug the power after operation. After the operation, the stylus shall be inserted into the slot on the main

unit, and put away the cable and connector, etc accessories to the box to avoid the lost.

Unplug the power cable by holding the connector, not the cable itself.

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Table of Contents

1 FOREWORD ...................................................................................... 1

1.1 INTRODUCTIONS ........................................................................... 1 1.2 PRODUCT FEATURES..................................................................... 1 1.3 PRODUCT FUNCTION..................................................................... 2 1.4 TECHNICAL PARAMETERS .............................................................. 2

2 STRUCTURE AND ACCESSORIES ................................................. 3

2.1 SCOPEBOX STRUCTURE................................................................ 3 2.2 SCOPEBOX ACCESSORIES............................................................. 4

3 AUTOMOTIVE OSCILLOSCOPE...................................................... 6

3.1 CONNECTION................................................................................ 6 3.2 INITIAL INTERFACE INTRODUCTION................................................. 6 3.3 OPERATIONS................................................................................. 7

3.3.1 Channel selection and attributes setting ..............................7 3.3.2 Trigger setting.......................................................................9 3.3.3 Auto calibration...................................................................11 3.3.4 Display settings ................................................................. 12 3.3.5 Channel and cursor measurement.................................... 12 3.3.6 File management............................................................... 13 3.3.7 View the software version ................................................. 15 3.3.8 Exit the application ............................................................ 15

4 AUTOMOTIVE IGNITION WAVEFORM .......................................... 16

4.1 SECONDARY-DISTRIBUTOR IGNITION ANALYSIS............................. 16 4.2 SECONDARY-SIMULTANEOUS IGNITION ANALYSIS.......................... 19 4.3 SECONDARY-DIRECT IGNITION ANALYSIS...................................... 20 4.4 WAVEFORM ANALYSIS MODE........................................................ 22


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1 Foreword

1.1 Introductions

X-431 PAD is a new generation of sophisticated and integrated automotive diagnostic product with colorful screen and powerful functions developed by LAUNCH, and Scopebox is an optional function box for X-431 PAD, including automotive oscilloscope and automotive ignition waveform.

Automotive oscilloscope can make the auto repair technician quickly judged the faults on automotive electronic equipment and wiring, and the oscilloscope sweep speed is far greater than the signal frequency of such vehicles, usually 5-10 times of the measured signal. The automotive oscilloscope not only can quickly capture the circuit signal, but also can slowly display the waveform to observe and analyze. It can also record and store the tested signal waveform which can be played back to observe for the fast signal, having great convenience to failure analysis. Either high-speed signal (e.g.: injection nozzle, intermittent fault signal) or the slow-speed signal (e.g. the throttle position change and the oxygen sensor signal) can be observed through automotive oscilloscope in an appropriate waveform.

The electronic signal can be compared and judged via measuring five parameters indexes. The five parameters indexes are the amplitude (the maximum voltage of signal), the frequency (the cycle time of signal), the shape (the appearance of signal), the pulse width (the duty cycle or the time range of signal), and the array (the repetition characteristic of signal), which can be tested, displayed, saved by the automotive oscilloscope. Via the waveform analysis can further detect the circuit fault on sensors, actuators, circuits, and electronic control units, etc.

1.2 Product features

Rapidly capture the circuit signal. Display waveform slowly for observation and analysis. Record and store the tested signal waveform for playback and failure

analysis.

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Detect, display and store all the electrical signal of five parameters, namely amplitude, frequency, shape, pulse width, and array.

1.3 Product function

Provides specialized automotive oscilloscope function and supports ignition waveform analysis.

1.4 Technical parameters

Scopebox: 4 channels, highest sampling frequency 200MHZ, max storage depth 64MSa, 8-bit resolution.


2 Structure and Accessories

2.1 Scopebox structure

Fig 2-1 Scopebox Structure Diagram

Table 2-1 shows the ports and indicators for X-431 PAD Scopebox

No. Name Description

1 CH1 Channel 1

2 CH2 Channel 2

3 CH3 Channel 3

4 CH4 Channel 4

5 External trigger External trigger signal

6 Fixed signal generator

Generate a square signal with fixed 1K frequency

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7 Power indicator Oscilloscope power indicator, which will be steady red after the oscilloscope is powered on

8 Operating indicator

The indicator will be steady green after the oscilloscope operated.

9 Communication indicator

After the data communication, the indicator will blink (Green).

10 Power interface Connect to power supply via the power adapter.

11 B-shaped USB interface

Connect main unit via USB connect line as separated individual USB devices

2.2 Scopebox accessories

Scopebox includes the secondary pickup cable for 4-channel oscilloscope, crocodile clips for 4-channel oscilloscope, etc. See Table 2-2.

As the product configuration can be different, the accessories included with the product may differ from the accessories listed on this manual. Please see the packing list attached to the product for the detailed accessories.

Table 2-2 Accessory checklist

No. Name Picture1 Secondary ignition pickup for

4-channel oscilloscope

2 Crocodile clips for 4-channel Oscilloscope

3 Direct ignition extension cord

4


4 6-way universal guide line for 4-channel oscilloscope

5 BNC to 4mm connector test cable

6 Pin connector for 4-channel oscilloscope

5


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3 Automotive Oscilloscope

3.1 Connection

X-431 PAD Scopebox should work with the X431 PAD main unit.

1. Firstly, power on the main unit (Connect one end of the power adaptor intothe power interface of main unit, and the other end to the DC 12V powersupply. Alternatively it can be also powered by cigarette lighter cable anddouble clip power cord).

2. Then plug one end of ground cable of oscilloscope into external triggerchannel (GND), the other end should be grounded.

3. Connect one end of probe cable of oscilloscope to the CH1, CH2, CH3, orCH4 on oscilloscope module, and then connect the other end to relatedsignal terminal.

Warning: please use the specific capacitance probe when diagnosing the ignition high voltage line. Never connect the oscilloscope to the ignition secondary circuit directly.

3.2 Initial interface introduction Fig. 3-1 displays the initial interface of oscilloscope.


Fig.3-1

Button descriptions: [Autoset]: It indicates auto trigger setting. Based on the characteristics of measured signal, the oscilloscope will automatically set the horizontal baseline, vertical sensitivity and trigger condition so that the waveform can be displayed. [File]: provides waveform record and waveform replay. [View]: Calibration and display settings are available. [Measure]: includes signal source measurement, cursor measurement and clear measurement. [Settings]: displays or hides the parameter settings area including horizontal settings, vertical settings and trigger settings. [Start/stop]: starts/stops collecting oscilloscope waveforms.

3.3 Operations

3.3.1 Channel selection and attributes setting <1> Channel selection

There are two ways available for channel selection: (See Fig. 3-2) A. Select from the channel column shown at the bottom of the waveform

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display area;

B. Select from Vertical settings.

Note: For better comparison and identification, each channel and waveform are marked in different colors.

Fig.3-2

<2> Channel attributes setting Channel attributes can be set via horizontal settings and vertical settings.

Horizontal Settings User can make some settings directly by clicking << or >> next to options. Alternatively, Click located in the upper right corner of the horizontal settings to make more settings. See Fig. 3-3.

Fig. 3-3

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Options descriptions:

Time/DIV: click << or >> to adjust;

Y-T Format: click << or >> to adjust. It includes 3 options: Normal, Scan and Scroll (from right to left).

Vertical Settings User can make some settings directly by clicking << or >> next to options. Alternatively, Click located in the upper right corner of the vertical settings to make more settings. See Fig. 3-4.

Fig. 3-4


A. Channel selection; B. Channel switch selection; C. Channel voltage adjustment; D. Channel coupling modes selection: DC, AC or Ground; E. Channel probe selection; F. Bandwidth limit switch; G. Channel reverse phase switch.

3.3.2 Trigger setting

Trigger indicates that when certain waveform meets the conditions that are predefined according to the requirements, the oscilloscope captures the waveform and its adjacent section, and then presents it on the screen.

<1> Trigger mode It is classified into 3 categories: Pulse Width and Edge.

[Edge]: It is the most common and effective trigger mode, which is widely used

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in most applications. Edge trigger only detects the edges, polarities, and voltage of signal. When the voltage of measured signal varies as identical as the preset one (rising edge or falling edge), and the value becomes same as trigger voltage, the oscilloscope will be triggered and capture the waveform.

[Pulse Width]: Trigger happens when it reaches to the pulse width.

Fig. 3-5 and Fig. 3-6 show edge trigger, pulse width trigger setting interfaces.

Fig. 3-5

Fig. 3-6

<2> Trigger Sweep

Auto, Normal and Single are included.

Auto: It indicates that no matter whether it meets the trigger conditions, it will refresh the waveform in real time. In this case, the waveform displayed on the screen seems swaying; Normal: Only it meets the trigger conditions can trigger be activated. Otherwise the waveform will keep still. Single: In this mode, it only captures the waveform that generates for the first time the trigger conditions are met, and then stops after finishing capture.

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<3> Trigger source Trigger source means which channel signal will be measured as trigger object. Before making settings to trigger mode and voltage of certain channel, you have to choose the target channel.

3.3.3 Auto calibration This option enables you to obtain a precise measurement of measured signal. Auto calibration mainly includes: calibration of analog channel, trigger voltage calibration of trigger circuit and nonlinear calibration of horizontal baseline movement.

Click “View” and then click [Calibration], a dialog box similar to Fig. 3-8 will appear.

Fig. 3-8 Check the box before the channel to select it. To select all, click [Check All]. To deselect it, just click [Reverse]. After choosing the desired channel(s), click [Start] to start calibration and [Calibration] button will be temporarily invalid during calibrating. Click [Stop] to stop calibrating. Once it becomes active, it indicates calibration has completed. Notes: In process of calibration, make sure CH1/CH2/CH3/CH4 has no signal

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input. Moreover, calibration may take several minutes and please be patient to wait.

3.3.4 Display settings Click “View” and then [Display settings] to enter the setting screen. See Fig. 3-9.

Fig. 3-9 Click “Vectors” or “Dots” to define display mode. Check/uncheck the box before Grid to open/close grid display.

3.3.5 Channel and cursor measurement <1> Channel measurement

Click “Measure” and then [Source], a screen similar to Fig. 3-10 will appear.

Fig. 3-10 <2> Cursor measurement

Click “Measure” and then [Cursor Measure], a screen similar to Fig. 3-11 will appear.

Note: if no desired channel is selected, the system will take the current source as the default channel.

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Fig. 3-11 Fig. 3-12

Horizontal Measure is for voltage (see Fig. 3-11) and vertical measure is for timebase (see Fig. 3-12).


[A Line / B Line move up / down]: fine adjustment for voltage. A line is a solid line and B line is a dotted line; [A Line / B Line move left / right]: fine adjustment for timebase. A line is a solid line and B line is a dotted line.

<3> Clear Measurement

Click “Measure” and then [Clear Measure], the system will clear the measurement result.

3.3.6 File management <1> Record waveform This function is used to record waveforms that are collected by oscilloscope at a period, and save it as data file which can be played back in future.

It can be performed only when the oscilloscope is collecting data in Normal mode.

Click [File], then select [Record] from the pop-up menu to start recording. See Fig. 3-13.

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Fig.3-13

Click [Record] to start recording, and the Record button becomes Stop button. Click [Stop] to stop recording. While recording, the recorded pages will be shown on the screen.

<2> Import waveform for playback The Import function enables you to import the stored waveform file for playback and review. During replaying, the oscilloscope stops collecting data automatically.

Click [File], then select [Waveform replay] from the pop-up menu to enter a screen similar to Fig. 3-14.

Fig.3-14

Select the playback file first, and then click [OK] button to open the waveform file, then use channel attributes setting to adjust the waveform display.

To delete the waveform file, please enter “My Data” and choose the

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corresponding folder to perform delete operation.

<3> Print waveform This option allows you to print out the latest collected data while the oscilloscope stops collecting data. While printing, the oscilloscope should be in stop mode.

Click on the shortcut bar to start printing.

3.3.7 View the software version Click to view the version information of the oscilloscope.

3.3.8 Exit the application Click to exit the current application.

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4 Automotive Ignition waveform The ignition system is the system which has greatest impact on the performances of gasoline engine, as the statistical data shows that nearly half of the failures are caused by poor work of electrical system. And the performance tests of engine often start from the ignition system. Nowadays ignition system includes distributor and distributorless. Distributorless includes independent ignition and simultaneous ignition.

1. Distributor ignition system i.e. contact breaker with contact-controlledignition system (commonly known as the platinum) and contact breakerwith noncontact-controlled ignition system combined with magnet, hallcomponents or infrared.

2. Independent ignition system: crankshaft sensor send out the ignitiontiming signal and cylinder identification signal so that the ignition systemcan send out ignition signal to specified cylinder in specified time, eachcylinder has its independent ignition coil.

3. Simultaneous ignition system: two cylinders share one ignition coil, whentwo cylinder pistons reach top dead center at the same time (one iscompression, another is the exhaust), two spark plugs will be ignited atthe same time, at this time, the ignition for the former cylinder is inhigh-pressure low temperature gas mixture, the ignition is valid, while forthe latter one is in low-pressure high temperature exhaust gas, theignition is invalid.

X-431 PAD can test and analyze the secondary signal for various engine ignition systems.

4.1 Secondary-distributor ignition analysis Connections: Plug the BNC end of secondary ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox, then connect the high-voltage clip to high-voltage line, and crocodile clips to ground.

Tips: Common ignition sequence (the specific sequence is subject to the actual engine ignition sequence)


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Four-stroke in-line four-cylinder: 1—2—4—3, or 1—3—4—2 Four-stroke in-line six-cylinder: 1—5—3—6—2—4, or 1—4—2—6—3—5 Four-stroke in-line eight-cylinder: 1—8—4—3—6—5—7—2 Five-cylinder: 1-2-4-5-3

V 6 engine: generally speaking, based on the person sitting on the driver cab, if the right side cylinder numbers on the right side, from the front to the back are as follows: 1, 3, 5; and the cylinder numbers on the left side, from the front to the back are as follows: 2, 4, 6; then the ignition sequence is: 1－4－5－2－3－6. If the cylinder numbers on the right side, from the front to the back are as follows: 2, 4, 6; and cylinder numbers on the left side, from the front to the back are as follows:1, 3, 5; then the ignition sequence is: 1－6－5－4－3－2.

The Figure 4-1 below shows the normal ignition waveform of distributor ignition system, the upper one is the secondary waveform, and the lower one is the primary waveform.

The secondary waveform A section is contact open period; B section is make contact period, which is the magnetizing field of ignition coil.


Fig. 4-1

1) Contact break point: the primary circuit of ignition coil cut off, thesecondary voltage was sensed and increased sharply

2) Ignition voltage: secondary coil voltage overcome the damper of highvoltage line, the contact breaker gap and the spark plug gap to releasemagnetizing energy, 1-2 section is the breakdown voltage

3) Spark voltage: For the capacitor discharge voltage4) Ignition voltage pulse: For the charge and discharge sections5) Spark line: The inductance discharge process, i.e. the mutual inductance

voltage of ignition coil maintains the conduction of secondary circuit6) Contact point close the current flow into primary coil, the primary coil

oscillates due to the mutual inductance.

Primary ignition waveform Section a shows the voltage oscillation on the primary circuit due to the magnetic induction of spark in the duration; Section b shows the damped oscillation generated by remaining magnetic field

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energy after the spark;

Section c shows the make contact magneting period of primary coil.

Seen from the waveform, the amplitudes of breaker contact closed angle, break angle and breakdown voltage and spark voltage are very clear, besides, the spark delay period and two oscillations can also be tested. For the ignition system without faults, compared with the whole cycle, the contact closed angle just 45%-50% (four-cylinder), 63%-70% (six-cylinder), or 64%-71% (eight-cyliner); the breakdown voltage is over 15kv; the spark voltage is about 9kV, the spark period is greater than 0.8ms. If these values or waveform are abnormal, it means there is fault or the system needs to be adjusted.

4.2 Secondary-simultaneous ignition analysis Connections: Plug the BNC end of secondary ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox, then connect the high-voltage clip to high-voltage line, and crocodile clips to ground.

Connection as shown in figure 4-2:

Fig. 4-2

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Fig. 4-3 below shows the valid and invalid ignition waveforms. Under the working status of valid ignition, the breakdown voltage and spark voltage are higher because the cylinder is filled with fresh combustible mixture gas, which has a lower ionization level and vice versa.

Fig. 4-3

4.3 Secondary-direct ignition analysis Connection： 1) When the high-voltage wire is exposed, plug the BNC end of secondary

ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox, then connect the high-voltage clip to high-voltage line, and crocodile clips to ground.

2) If no high-voltage wire exposes, dismantle ignition coil of tested cylinderand use direct ignition extension cord. Connect one end to ignition coil which should be grounded via direct ignition grounding wire, and insert the other end into cylinder to joint with spark plug. Then plug the BNC end of secondary ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox, then connect the high-voltage clip to high-voltage line, and crocodile clips to ground.

Connections are shown in Fig. 4-4:

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Fig. 4-4

Fig. 4-5 shows the normal secondary (the upper one) and (the lower one) primary ignition waveform of direct ignition system. Beause the on/off of primary circuit is not opening/closing of mechanical contact, but the conduction of transistor. The primary voltage has no obvious oscillations within the duration, but the voltage increases during the magnetization process due to current limiting, and this change can cause corresponding fluctuations of secondary voltage line as a result of induction of ignition coil.

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Fig. 4-5

4.4 Waveform analysis mode The ignition secondary single-cylinder waveform test is mainly used to: a. Analyze the ignition dwell angle of single cylinder.(ignition coil charging

time)

b. Analyze the capability of ignition coil and secondary high tension circuit(from ignition line to ignition voltage line).

c. Find the improper mixture A/F ratio of single cylinder (from combustionline).

d. Analyze the capability of capacitance (platinum or ignition system).

e. Find the spark plug that causes misfire of the cylinder (from combustionline).

This test can provide very meaningful information about the combustion quality for each cylinder. If necessary, this test can also be performed during driving. Since the secondary ignition waveform is significantly affected by different engines, fuel systems and ignition conditions, it is useful for detecting the faults

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of engine mechanical parts, fuel system components, and ignition system components. Different parts of the waveform can specify that some components and systems on the specific cylinder have faults. Refer to the instructions for various parts of waveform for the related component working status of specific waveform section.

Test methods and conditions: Start the engine or drive the vehicle accroding to the driving performance fault or poor ignition, etc. Confirm the consistence of judgement standard (the amplitude, frequency, shape and pulse width, etc., for each cylinder), check the fault of the waveform for corresponding components.

Waveform results: observe the ignition coil at the beginning of charging, the relative consistent falling edge represents the dwell angle and ignition timing of each cylinder are precise.

Ignition line: Observe the height consistence of flashover voltage. Too high flashover voltage (even out of the oscilloscope screen) represents a high resistance existed in the ignition secondary circuit (for example, open circuit, or damaged spark plug or high voltage line, or too large time gap on spark plug), while the too short sparking voltage represents the resistance of ignition secondary circuit is lower than normal value (due to pollutant and broken spark plug or the high voltage line of spark plug has electrical leakage, etc.).

Spark or combustion voltage: Observe the consistence of spark or combustion voltage, as it represents the consistence of spark plug and the air-fuel ratio of each cylinder. In case that the mixing ratio is too lean, the combustion voltage will be lower than normal value.

Combustion line: Observe the spark or the combustion line which shall be clean with few clutter, as lots of clutter indicates the cylinder has poor ignition due to ignite too early, damaged nozzle, pollutant spark plug, or other reasons. The duration of combustion line indicates the mixing ratio of the cylinder is abnormal lean or


rich. Too long combustion line (usually greater than 2ms) represents the mixing ratio is rich, whereas too short of combustion line (usually less than 0.75ms) represents the mixing ratio is lean.

Ignition coil oscillation: Observe at least two oscillation waveforms after the combustion line, which will be better if more than three oscillation waveforms, as it represents the ignition coil and capacitor (on Platinum or ignition system) are normal.

Primary voltage analysis

According to the faulty primary voltage waveform collected by the ignition analysis, the related components and mechanical equipment status of ignition system electrical circuit can be analyzed, which provides a reliable basis for the adjustment and maintenance of power circuit to avoid the blind demolition. The waveform shown on Fig. 4-6, appears a lot of clutter on the contact break point, which is obviously caused by the serious erosion on contact break point. It can be verified via burnishing the contact or changing the circuit breaker.

Fig. 4-6

For the primary voltage waveform shown on Fig. 4-7, the damped attenuation cycles obviously reduced on the spark period, the amplitude became lower, which is evidently caused by capacitor leakage.

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Fig. 4-7

The waveform on Fig. 4-8, shows the accidental pumping during contact closing period. The irregular beating is caused by insufficient spring force.

Fig. 4-8

The curve on Fig. 4-9 shows the contact angle is too small during the magnetizing period, which is caused by too large contact gap.

Fig. 4-9

A lot of clutter will be displayed on the horizontal section of primary waveform if contact has poor grounding, as shown below figure 4-10.

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Fig.4-10

Fig. 4-11 shows the fault of low-voltage waveform in electronic ignition system. The voltage does not rise during magnetizing, which indicates that the effect of limitation of the circuit failed and no components on distributorless ignition system can be adjusted. When this waveform is abnormal, you can only replace the ignition coils, igniter, ignition signal generator and cam position sensor, etc., one by one, to find out the faulty component or module.

Fig. 4-11

The secondary waveform is also affected by the spark plug, the combustion process, mixture gas composition, the engine thermal state of the ignition coil, etc., which is more complicated. The following lists a large number of measured secondary faulty waveform for reference. Since various factors lead to the failures, Fig. 4-12 just shows the major possible factors for the failures.

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27


Fig 4-12

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LAUNCH Android-based Scopebox User’s Manual

1 Foreword

1.1 Introductions

The scopebox is an optional add-on module for Launch’s Android-based diagnostic tool, including automotive oscilloscope and automotive ignition waveform.

Automotive oscilloscope can make the auto repair technician quickly judge the faults on automotive electronic equipment and wiring, and the oscilloscope sweep speed is far greater than the signal frequency of such vehicles, usually 5-10 times of the measured signal. The automotive oscilloscope not only can quickly acquire the circuit signal, but also can slowly display the waveform to observe and analyze. It can also record and store the tested signal waveform which can be recalled to observe for the fast signal, having great convenience to failure analysis. Either high-speed signal (e.g.: Injection nozzle, intermittent fault signal) or the slow-speed signal (e.g. the throttle position change and the oxygen sensor signal) can be observed through automotive oscilloscope in an appropriate waveform.

The electronic signal can be compared and judged via measuring five parameters indexes. The five parameters are the amplitude (the maximum voltage of signal), the frequency (the cycle time of signal), the shape (the appearance of signal), the pulse width (the duty cycle or the time range of signal), and the array (the repetition characteristic of signal), which can be tested, displayed, saved by the automotive oscilloscope. Via the waveform analysis can further detect the circuit fault on sensors, actuators, circuits, and electronic control units, etc.


Rapidly capture the circuit signal. Display waveform slowly for observation and analysis. Record and store the tested signal waveform for playback and failure

analysis. Detect, display and store all the electrical signal of five parameters, namely


amplitude, frequency, shape, pulse width, and array.




Scopebox: 4 channels, highest sampling frequency 200MHZ, max. storage depth 64MSa, 8-bit resolution.




Fig 2-1 Scopebox Structure Diagram

Table 2-1 shows the ports and indicators for the scopebox.

No. Name Description

1 CH1 Channel 1

2 CH2 Channel 2

3 CH3 Channel 3

4 CH4 Channel 4

5 External trigger External trigger signal

6 Fixed signal generator

Generate a square signal with fixed 1K frequency.


7 Power indicator It keeps steady red after the scopebox is powered on.

8 Running indicator

It remains steady green after the scopebox is running.

9 Communication indicator

It blinks in process of data communication.



Connect main unit via USB cable as separated individual USB devices.

2.2 Scopebox accessories

The scopebox includes the secondary pickup cable for 4-channel oscilloscope, crocodile clips for 4-channel oscilloscope, etc. See Table 2-2.

As the product configuration can be different, the accessories included with the product may differ from the accessories listed on this manual. Please see the packing list attached to the product for the detailed accessories.


No. Name Picture1 Secondary ignition pickup for


2 Crocodile clips for 4-channel oscilloscope

3 Direct ignition extension cord




6 Pin connector suite for 4-channel oscilloscope



3.1 Connection

The scopebox should work with the Launch’s Android-based diagnostic tool. 1. Firstly, power on the diagnostic tool.2. Then plug one end of ground cable of the scopebox into external trigger

channel (GND), the other end should be grounded.3. Connect one end of probe cable to the CH1, CH2, CH3, or CH4 on the

scopebox, and then connect the other end to related signal terminal.

Warning: Please use the specific capacitance probe when diagnosing the ignition high voltage line. Never connect the scopebox to the ignition secondary circuit directly.

3.2 Initial interface introduction Fig. 3-1 displays the initial interface of the scopebox.

Fig. 3-1


No. Descriptions

1 Signal display area

2 Horizontal Settings: Controls the time base.

3 Vertical Settings: Controls the amplitude of the displayed signal.

4 Trigger Settings: Controls the start event of the sweep.

5 Channel Selection Button

6 Function Menu

[Auto]: It indicates auto trigger setting. See Chapter 3.3.2.

[Ref]: There are expert reference and base reference

available. Expert reference enables you to recall your customized

expert database, whereas base reference provides automatic

pre-setting function of specialized sensors. See Chapter 3.3.6.

[File]: Provides save snapshot, snapshot manager, waveform

record and waveform replay. See Chapter 3.3.5.

[View]: Calibration and display settings are available. See

Chapter 3.3.3.

[Measure]: Includes signal source measurement, horizontal

measurement, vertical measurement and clear measurement. See

Chapter 3.3.4.

[Settings]: Shows/hides the parameter settings area

including horizontal settings, vertical settings and trigger settings.

/ [Start/Stop]: Starts/stops collecting waveforms.


3.3 Operations

3.3.1 Channel selection and attributes setting <1> Channel selection

There are two ways available for channel selection: (See Fig. 3-2) A. Select from the channel tab shown at the bottom of the waveform display area;

B. Select from Vertical settings.

Note: For better comparison and identification, each channel and waveform are marked in different colors.

Fig.3-2

<2> Channel attributes & trigger setting Channel attributes can be set via horizontal settings and vertical settings.

Horizontal Settings User can make some settings directly by tapping < or > next to options. See Fig. 3-3.


Fig. 3-3


Menu Comments/Settings

Time/DIV Horizontal scale. If the waveform acquisition is stopped

(using the / button), the Time/DIV selector

expands or compresses the waveform.

Y-T format The conventional oscilloscope display format. It shows

the voltage of a waveform record (on the vertical axis)

as it varies over time (on the horizontal axis).

Vertical Settings The trigger determines when the scopebox starts to acquire data and display a waveform. When a trigger is set up properly, it can convert unstable displays or blank screens into meaningful waveforms.

When the scopebox starts to acquire a waveform, it collects enough data so that it can draw the waveform to the left of the trigger point. The scopebox continues to acquire data while waiting for the trigger condition to occur. After it detects a trigger, the scopebox continues to acquire enough data so that it can draw the waveform to the right of the trigger point.

User can make some settings directly by tapping < or > next to options. See Fig. 3-4.


Fig. 3-4



Channel To select the channel source.

Volts/DIV It is defined as “Volts/Division” and mainly used to change the resolution.

Coupling Trigger coupling determines what part of the signal passes to the trigger circuit. AC, DC and Ground are included:

AC: Blocks the DC component of the input signal;

DC: Passes both AC and DC components of the input signal;

Ground: Disconnects the input signal.

Probe When using a probe, the scopebox allows you to select the attenuation factor for the probe. The attenuation factor changes the vertical scaling of the scopebox so that the measurement results reflect the actual voltage levels at the probe tip.

BW Limit ON: Limits the channel bandwidth to 20MHz to reduce display noise.

OFF: Get full bandwidth.

Invert ON: Turn on the invert function.


OFF: Restore to the original display of the waveform.

Trigger setting Trigger indicates that when certain waveform meets the conditions that are predefined according to the requirements, the scopebox acquires the waveform and its adjacent section, and then presents it on the screen.

Fig. 3-5

1) If Edge trigger is selected (An edge trigger determines whether thescopebox finds the trigger point on the rising or the falling edge of a signal.):


Sweep The sweep mode determines how the scopebox behaves in the absence of a trigger event. The scopebox provides three trigger modes: Auto, Normal, and Single.

Auto: It allows the scopebox to acquire waveforms even when it does not detect a trigger condition. If no trigger condition occurs while the scopebox is waiting for a specific period, it will force itself to trigger. When forcing invalid triggers, the scopebox can not synchronize the waveform, and then waveform seems to roll across the display. If valid triggers occur, the


display becomes stable on the screen. Normal: This mode allows the scopebox to acquire a waveform only when it is triggered. If no trigger occurs, the scopebox keeps waiting, and the previous waveform, if any, will remain on the display. Single: In this mode, it only acquires the waveform that generates for the first time the trigger conditions are met, and then stops after finishing capture.

Source Select which channel as trigger signal.

Slope + : Trigger on rising edge - : Trigger on falling edge

High Freq

Rejection

Reject high frequency signals when selected.

2) If Pulse Width trigger is selected (Pulse trigger occurs according to thewidth of pulse. The abnormal signals can be detected through setting up the pulse width condition):


Sweep The sweep mode determines how the scopebox behaves in the absence of a trigger event. The scopebox provides three trigger modes: Auto, Normal, and Single.

Auto: It allows the scopebox to acquire waveforms even when it does not detect a trigger condition. If no trigger condition occurs while the scopebox is waiting for a specific period, it will force itself to trigger. When forcing invalid triggers, the scopebox can not synchronize the waveform, and then waveform seems to roll across the display. If valid triggers occur, the display becomes stable on the screen. Normal: This mode allows the scopebox to acquire a


waveform only when it is triggered. If no trigger occurs, the scopebox keeps waiting, and the previous waveform, if any, will remain on the display. Single: In this mode, it only acquires the waveform that generates for the first time the trigger conditions are met, and then stops after finishing capture.

Source Select which channel as trigger signal.

Condition To select pulse condition.

Pulse Width Set required pulse width.

High Freq

Rejection

Reject high frequency signals when selected.

3.3.2 Auto

The scopebox has an Auto feature that sets up the scopebox automatically to

display the input signal in a best fit.

Tap , the scopebox may change the current settings to display the signal.

It automatically adjusts the vertical and horizontal scaling, as well as the trigger

coupling, position, slope, level and mode settings.

3.3.3 View Settings <1> Calibration This option adjusts the scopebox’s internal circuitry to get the best accuracy. Use this function to calibrate the Scopebox’s vertical and horizontal systems.

Tap and then tap [Calibration], a dialog box similar to Fig. 3-6 will appear.


Fig. 3-6

Check the box before the channel to select it. To deselect it, just uncheck it. After choosing the desired channel(s), tap [Start] to start calibration and [Start] button will be temporarily invalid during calibrating. Tap [Stop] to stop calibrating. Once it becomes active, it indicates calibration has completed. Notes: In process of calibration, make sure CH1/CH2/CH3/CH4 has no signal input. Moreover, calibration may take several minutes and please be patient to wait.

<2> REF settings Reference waveforms are saved waveforms to be selected for display. The reference function will be available after saving the selected waveform to non-volatile memory.

Tap and then [REF] to enter the REF setting screen. See Fig. 3-7.


Fig. 3-7

Tap < or > to select the desired reference value for time/DIV and volts/DIV. To

show or hide the REF, just check/uncheck the box before On/Off.

<3> Display settings

Tap and then [Display settings] to enter the setting screen. See Fig. 3-8.

Fig. 3-8 Select “Vectors” or “Dots” to display waveforms as vectors or dots. Check/uncheck the box before Grid to turn on/off grid display.

3.3.4 Measure <1> Channel source

Tap and then [Source], a screen similar to Fig. 3-9 will appear.


Fig. 3-9 <2> Horizontal / Vertical measure

Horizontal Measure / Vertical Measure are used to measure voltage parameter

and time parameter respectively. Drag A line upwards or downwards to control

voltage. Move A line left or right to fine-tune timebase. A line is a solid line and

B line is a dotted line.

Tap and then [Horizontal Measure], a screen similar to Fig. 3-10 will

appear.

Fig. 3-10


Note: If no desired channel is selected, the system will take the current source as the default channel.

<3> Clear measure

Tap and then [Clear Measure], the system will clear the measurement

result on screen.

3.3.5 File management <1> Save snapshot

While viewing sampling data, tap and then [Save Snapshot] to store the

current screen.

<2> Snapshot manager

While viewing sampling data, tap and then [Snapshot Manager] to enter.

View, delete and edit operations are supported.

<3> Record waveform This function is used to record input waveforms that are acquired by the scopebox at a specific period, and save it as waveform file which can be recalled in future.

It can be performed only when the scopebox is collecting data in Normal mode.

Tap , then select [Record] from the pop-up menu to start recording. See

Fig. 3-11.


Fig.3-11

Tap [Start] to start recording with a minimum record length of 10 frames, and [Stop] to stop recording. While recording, the recorded pages will be shown on the screen.

<4> Load waveform for playback The Import function enables you to import the stored waveform file for playback and review. During replaying, the scopebox stops collecting data automatically.

Tap , then select [Waveform replay] from the pop-up menu to enter a

screen similar to Fig. 3-12.


Fig.3-12

Select the file first, and then tap to open the waveform file. Tap to

starting the playback and tap to stop it.

Fig.3-13

To delete the waveform file, tap .

Tap to return to the previous screen.


3.3.6 Expert Reference <1> Expert Reference By default, it appears blank. As a matter of fact, Expert reference database is generated by doing the following:

1. Open and edit a snapshot;

2. Select “Joint the expert database” (refer to the following illustration), and

then tap to save the waveform being displayed on the screen as REF.

Fig. 3-14

Tap and then [Expert Reference] to enter, the following operation can be

done:

: To load and recall the selected file.

: To delete the selected file.

: To edit the selected file.

<2> Base Reference

Preset waveforms of some sensors are available for your reference.


Fig. 3-15

3.3.7 Exit the application Tap to exit the current application.



1. Distributor ignition system i.e. contact breaker with contact-controlledignition system (commonly known as the platinum) and contact breakerwith noncontact-controlled ignition system combined with magnet, hallcomponents or infrared.

2. Independent ignition system: Each spark plug has its own individual coilthat sits right on top of it, also called coil on plug system. Crankshaftsensor send out the ignition timing signal and cylinder identification signalso that the ignition system can send out ignition signal to specifiedcylinder in specified time, each cylinder has its independent ignition coil.

3. Simultaneous ignition system: Two spark plugs share the same coil, alsocalled waste spark system. When two cylinder pistons reach top deadcenter at the same time (one is compression, another is the exhaust), twospark plugs will be ignited at the same time, at this time, the ignition forthe former cylinder is in high-pressure low temperature gas mixture, theignition is valid, while for the latter one is in low-pressure high temperatureexhaust gas, the ignition is invalid.

The scopebox can test and analyze the secondary signal for various engine ignition systems.

4.1 Secondary-distributor ignition analysis Connections: Plug the BNC end of secondary ignition pickup into CH1/CH2/CH3/CH4 channel of the scopebox, and then connect the high-voltage clip to high-voltage line, and crocodile clips to ground.

Tips: Common ignition sequence (the specific sequence is subject to the


actual engine ignition sequence) Four-stroke in-line four-cylinder: 1-2-4-3, or 1-3-4-2 Four-stroke in-line six-cylinder: 1-5-3-6-2-4, or 1-4-2-6-3-5 Four-stroke in-line eight-cylinder: 1-8-4-3-6-5-7-2 Five-cylinder: 1-2-4-5-3

V 6 engine: Generally speaking, based on the person sitting on the driver cab, if the right side cylinder numbers on the right side, from the front to the back are as follows: 1, 3, 5; and the cylinder numbers on the left side, from the front to the back are as follows: 2, 4, 6; then the ignition sequence is: 1－4－5－2－3－6. If the cylinder numbers on the right side, from the front to the back are as follows: 2, 4, 6; and cylinder numbers on the left side, from the front to the back are as follows:1, 3, 5; then the ignition sequence is: 1－6－5－4－3－2.

The Figure 4-1 below shows the normal ignition waveform of distributor ignition system, the upper one is the secondary waveform, and the lower one is the primary waveform.

The secondary waveform A section is contact open period; B section is make contact period, which is the magnetizing field of ignition coil.


Fig. 4-1

1) Contact break point: The primary circuit of ignition coil cut off, thesecondary voltage was sensed and increased sharply

2) Ignition voltage: Secondary coil voltage overcome the damper of highvoltage line, the contact breaker gap and the spark plug gap to releasemagnetizing energy, 1-2 section is the breakdown voltage

3) Spark voltage: For the capacitor discharge voltage4) Ignition voltage pulse: For the charge and discharge sections5) Spark line: The inductance discharge process, i.e. the mutual inductance

voltage of ignition coil maintains the conduction of secondary circuit6) Contact point close the current flow into primary coil, the primary coil

oscillates due to the mutual inductance.

Primary ignition waveform Section a shows the voltage oscillation on the primary circuit due to the magnetic induction of spark in the duration; Section b shows the damped oscillation generated by remaining magnetic field


energy after the spark;

Section c shows the make contact magnetic period of primary coil.

Seen from the waveform, the amplitudes of breaker contact closed angle, break angle and breakdown voltage and spark voltage are very clear, besides, the spark delay period and two oscillations can also be tested. For the ignition system without faults, compared with the whole cycle, the contact closed angle just 45%-50% (four-cylinder), 63%-70% (six-cylinder), or 64%-71% (eight-cyliner); the breakdown voltage is over 15kv; the spark voltage is about 9kV, the spark period is greater than 0.8ms. If these values or waveform are abnormal, it means there is fault or the system needs to be adjusted.

4.2 Secondary-simultaneous ignition analysis Connections: Plug the BNC end of secondary ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox, then connect the high-voltage clip to high-voltage line, and crocodile clips to ground.

Connection as shown in figure 4-2:

Fig. 4-2



Fig. 4-3

4.3 Secondary-direct ignition analysis Connection： 1) When the high-voltage wire is exposed, plug the BNC end of secondary

ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox, thenconnect the high-voltage clip to high-voltage line, and crocodile clips toground.

2) If no high-voltage wire exposes, dismantle ignition coil of tested cylinderand use direct ignition extension cord. Connect one end to ignition coilwhich should be grounded via direct ignition grounding wire, and insert theother end into cylinder to joint with spark plug. Then plug the BNC end ofsecondary ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox,then connect the high-voltage clip to high-voltage line, and crocodile clipsto ground.

Connections are shown in Fig. 4-4:


Fig. 4-4

Fig. 4-5 shows the normal secondary (the upper one) and (the lower one) primary ignition waveform of direct ignition system. Because the on/off of primary circuit is not opening/closing of mechanical contact, but the conduction of transistor. The primary voltage has no obvious oscillations within the duration, but the voltage increases during the magnetization process due to current limiting, and this change can cause corresponding fluctuations of secondary voltage line as a result of induction of ignition coil.


Fig. 4-5

4.4 Waveform analysis mode The ignition secondary single-cylinder waveform test is mainly used to: a. Analyze the ignition dwell angle of single cylinder.(ignition coil charging

time)

b. Analyze the capability of ignition coil and secondary high tension circuit(from ignition line to ignition voltage line).

c. Find the improper mixture A/F ratio of single cylinder (from combustionline).

d. Analyze the capability of capacitance (platinum or ignition system).

e. Find the spark plug that causes misfire of the cylinder (from combustionline).

This test can provide very meaningful information about the combustion quality for each cylinder. If necessary, this test can also be performed during driving. Since the secondary ignition waveform is significantly affected by different engines, fuel systems and ignition conditions, it is useful for detecting the faults


of engine mechanical parts, fuel system components, and ignition system components. Different parts of the waveform can specify that some components and systems on the specific cylinder have faults. Refer to the instructions for various parts of waveform for the related component working status of specific waveform section.


Waveform results: Observe the ignition coil at the beginning of charging, the relative consistent falling edge represents the dwell angle and ignition timing of each cylinder are precise.

Ignition line: Observe the height consistence of flashover voltage. Too high flashover voltage (even out of the scopebox screen) represents a high resistance existed in the ignition secondary circuit (for example, open circuit, or damaged spark plug or high voltage line, or too large time gap on spark plug), while the too short sparking voltage represents the resistance of ignition secondary circuit is lower than normal value (due to pollutant and broken spark plug or the high voltage line of spark plug has electrical leakage, etc.).


Combustion line: Observe the spark or the combustion line which shall be clean with few clutter, as lots of clutter indicates the cylinder has poor ignition due to ignite too early, damaged nozzle, pollutant spark plug, or other reasons. The duration of combustion line indicates the mixing ratio of the cylinder is abnormal lean or


rich. Too long combustion line (usually greater than 2ms) represents the mixing ratio is rich, whereas too short of combustion line (usually less than 0.75ms) represents the mixing ratio is lean.


Primary voltage analysis

According to the faulty primary voltage waveform collected by the ignition analysis, the related components and mechanical equipment status of ignition system electrical circuit can be analyzed, which provides a reliable basis for the adjustment and maintenance of power circuit to avoid the blind demolition. The waveform shown on Fig. 4-6, appears a lot of clutter on the contact break point, which is obviously caused by the serious erosion on contact break point. It can be verified via burnishing the contact or changing the circuit breaker.

Fig. 4-6

For the primary voltage waveform shown on Fig. 4-7, the damped attenuation cycles obviously reduced on the spark period, the amplitude became lower, which is evidently caused by capacitor leakage.


Fig. 4-7

The waveform on Fig. 4-8, shows the accidental pumping during contact closing period. The irregular beating is caused by insufficient spring force.

Fig. 4-8

The curve on Fig. 4-9 shows the contact angle is too small during the magnetizing period, which is caused by too large contact gap.

Fig. 4-9

A lot of clutter will be displayed on the horizontal section of primary waveform if contact has poor grounding, as shown below figure 4-10.


Fig.4-10

Fig. 4-11 shows the fault of low-voltage waveform in electronic ignition system. The voltage does not rise during magnetizing, which indicates that the effect of limitation of the circuit failed and no components on distributorless ignition system can be adjusted. When this waveform is abnormal, you can only replace the ignition coils, igniter, ignition signal generator and cam position sensor, etc., one by one, to find out the faulty component or module.

Fig. 4-11

The secondary waveform is also affected by the spark plug, the combustion process, mixture gas composition, the engine thermal state of the ignition coil, etc., which is more complicated. The following lists a large number of measured secondary faulty waveform for reference. Since various factors lead to the failures, Fig. 4-12 just shows the major possible factors for the failures.



Fig 4-12

LAUNCH X431 GDS Scopebox Manual

1 Foreword

1.1 Introductions

X-431 GDS is a new generation of sophisticated and integrated automotive diagnostic product with colorful screen and powerful functions developed by LAUNCH, and Scopebox is an optional function box for GDS, including automotive oscilloscope and automotive ignition waveform.

Automotive oscilloscope can make the auto repair technician quickly judged the faults on automotive electronic equipment and wiring， and the oscilloscope sweep speed is far greater than the signal frequency of such vehicles, usually 5-10 times of the measured signal. The automotive oscilloscope not only can quickly capture the circuit signal, but also can slowly display the waveform to observe and analyze. It can also record and store the tested signal waveform which can be played back to observe for the fast signal, having great convenience to failure analysis. Either high-speed signal (e.g.: injection nozzle, intermittent fault signal) or the slow-speed signal (e.g. the throttle position change and the oxygen sensor signal) can be observed through automotive oscilloscope in an appropriate waveform.

The electronic signal can be compared and judged via measuring five parameters indexes. The five parameters indexes are the amplitude (the maximum voltage of signal), the frequency (the cycle


time of signal), the shape (the appearance of signal), the pulse width (the duty cycle or the time range of signal), and the array (the repetition characteristic of signal), which can be tested, displayed, saved by the automotive oscilloscope. Via the waveform analysis can further detect the circuit fault on sensors, actuators, circuits, and electronic control units, etc.


Rapidly capture the circuit signal. Display waveform slowly for observation and analysis. Record and store the tested signal waveform for playback and

failure analysis. Detect, display and store all the electrical signal of five

parameters, namely amplitude, frequency, shape, pulse width, and array.




Scopebox: 4 channels, highest sampling frequency 150MHZ, max storage depth 64MSa, 8-bit resolution




cture Diagram

Table 2-1 shows S Scopebox

Fig 2-1 Scopebox Stru

the ports and indicators for X-431 GD

No. Name Description 1 CH1 Channel 1 2 CH2 Channel 2 3 CH3 Channel 3 4 CH4 Channel 4 5 External trigger External trigger signal


6 Fixed signal square signal with fixed 1K generator

Generate afrequency

7 Power indicator Oscilloscope power indicator, which will be steady red after the oscilloscope is powered on

8 Operating indicator

The indicator will be steady green after the oscilloscope operated.

9 Communicaindicator

tion After the data communication, the indicator will blink (Green).



Connect main unit via USB connect line as separated individual USB devices

.2 S x acc

kup cable for 4-channel nel oscilloscope, etc. See

th the product may differ from the accessories listed on

2 copebo essories

Scopebox includes the secondary picoscilloscope, crocodile clips for 4-chanTable 2-2.

As the product configuration can be different, the accessories included withis manual. Please see the packing list attached to the product for the detailed accessories.



PictureNo. Name1 Secondary ignition pickup for


2 Crocodile clips for 4-channel Oscilloscope

3 xtension cordDirect ignition e



6 Pin connector for 4-channel oscilloscope



3.1 Connection

X-431 GDS Scopebox should work with the X431 GDS main unit.

1. Firstly, power on the main unit (Connect one end of the poweradaptor into the power interface of main unit, and the other endto the DC 12V power supply. Alternatively it can be also poweredby cigarette lighter cable and double clip power cord).

2. Then plug one end of ground cable of oscilloscope into externaltrigger channel (GND), the other end should be grounded.

3. Connect one end of probe cable of oscilloscope to the CH1, CH2,CH3, or CH4 on oscilloscope module, and then connect theother end to related signal terminal.

Warning: please use the specific capacitance probe when diagnosing the ignition high voltage line. Never connect the oscilloscope to the ignition secondary circuit directly.

3.2 Initial interface introduction

Fig. 3-1 displays the initial interface of oscilloscope.


Fig.3-1 Button descriptions: [System]: includes show desktop, Wi-Fi setting, current version and exit the program. [Help]: displays help files. [File]: supports import waveform, store waveform, store graphics, record waveform, print waveform, show/hide the grid, display cached interface, turn pages, and clear. [Trigger]: The following options are available: one-channel trigger / alternation trigger, trigger channel source, trigger types, trigger modes, horizontal trigger hold-off setting and auto calibration. [Measure]: measures the time and the voltage for the waveforms. [Start/stop]: starts/stops collecting oscilloscope waveforms. [Expert]: provides automatic pre-setting function of specialized sensors.


3.3 Operations

3.3.1 Channel selection and attributes setting <1> Channel selection There are two ways available for channel selection. A. Select from the channel menu; B. Select via each channle attribute button.

See Fig. 3-2.

Fig.3-2 <2> Channel attributes setting Each channel features five attributes. A. Channel switch selection. B. Channel voltage adjustment: + indicates increase voltage by one

level, while – indicates decrease voltage by one level. C. Channel time-base adjustment: + means to increase time-base


by one level and – means to decrease time-base by one level. D. Channel phase selection: normal phase or reverse phase. E. Channel coupling modes selection: DC, AC, or Ground.

See Fig. 3-3 and Fig. 3-4 for channel 1 & channel 4 attributes setting interfaces respectively.

Fig.3-3 Channel 1 attributes setting


Fig.3-4 Channel 4 attributes setting

3.3.2 Trigger setting

<1> Trigger source Single channel trigger and alternation trigger are included. [Single channel trigger]: collects all channels data by triggering one channel; [Alternation trigger]: Each channel collects data separately based on its own channel triggering, only for AUTO mode.

Fig. 3-5 and Fig. 3-6 show single channel trigger & alternation trigger setting interfaces.


Fig.3-5 Single channel trigger

Fig.3-6 Alternation trigger

<2> Trigger channel To set trigger mode and voltage for one channel, please select this channel first. See button [Trigger].


<3> Trigger type Includes edge trigger and pulse trigger, see button [Time base]. [Edge trigger]: Touch [edge] to select rising edge or falling edge; [Pulse trigger]: Touch button [pulse] to select. There are 6 modes available.

<4> Trigger mode It falls into: Auto, Normal and Single trigger. See button [Auto]. [Auto]: continuous trigger. Automatically trigger when it meets the trigger conditions; otherwise, the trigger will be forced by system; [Normal]: continuous trigger. Trigger only when the trigger conditions are met, or else trigger does not happen. [Single]: single trigger. Only trigger once when the trigger conditions are met.

<5> Horizontal trigger hold-off setting This option allows you to set the horizontal trigger position of the oscilloscope. It can be set by clicking the trigger icon directly or through the menu. See Fig. 3-7.


Fig.3-7 In Fig. 3-7, the yellow inverted triangle is the horizontal hold-off pointer. Button [Hold-off 50%] can coarsely tune the horizontal trigger, and make fine adjustment in the horizontal trigger hold-off zone.

<6> Auto calibration Click [Auto calibrated] button, the oscilloscope will perform automatic calibration. [Auto calibrated] button will be temporarily invalid during calibrating. Once it becomes active, it indicates calibration has completed. See Fig. 3-8.


Fig .3-8

3.3.3 Channel measurement <1> Timebase measurement

Fig.3-9


Button descriptions： [Timebase]: used to select mode. When it is displayed as timebase, it is in time measurement mode; [A line]: enables you to select A\B measurement line. The currently selected line is a solid line; Left\Right move: fine adjutment button for timebase; A\B line: time measurement line; Measurement value display area: an area for displaying time measurement result.

<2> Voltage measurement

Fig.3-10 Button descriptions： [Voltage]: used to select mode. When it is displayed as Volt, it is in voltage measurement mode;


[A line]: enables you to select A\B measurement line. The currently selected line is a solid line;[Up/Down]: fine adjutment button for voltage.

3.3.4 Expert settings

This option is specially designed to measure related vehicle sensors. After selecting one sensor, the osicilloscope will be preset based on preset value of this sensor. Click [Expert] to enter the expert setting interface. See Fig.3-11.

Fig.3-11 In Fig.3-11, left side lists sensor list and right side displays current sample waveform of selected sensor.


3.3.4 File management

<1> Store picture This option is designed to save the currently displayed waveforms as graphic file. It can be performed when the oscilloscope stops collecting data. Touch [File], then select [Store picture] from the pull-down list. See Fig. 3-12.

Fig.3-12

<2> Store waveform This item is to save the currently displayed waveforms as data file which can be played back by oscilloscope. It can be performed when the oscilloscope stops collecting data. Touch [File], then select [Store waveform] from the pull-down list. See Fig. 3-13.


Fig.3-13

<3> Record waveform This function is used to record waveforms that are collected by oscilloscope at a period, and save it as data file which can be played back in future. It can be performed when the oscilloscope stops collecting data. Touch [File], then select [Record] from the pull-down list to start recording. See Fig. 3-14.


Fig.3-14

[Record/Stop]: starts / stops recording. While recording, the recorded pages will be shown on the screen.

<4> Import waveform for playback The Import function enables you to import the stored waveform file for playback and review. It only works when the oscilloscope stops collecting data. Click [File], then select [Import] from the pull-down list. See Fig. 3-15.


Fig.3-15

To delete a waveform file, please select it first, then touch [Delete] button. Click [OK] button to open the waveform file, then use channel attributes setting to adjust the waveform display, or touch [File] ->[Pre Pg.]\ [Next Pg.] to turn pages. See Fig. 3-16.


Fig.3-16

<5> Print waveform This option allows you to print the currently displayed waveform out through a specific printer. Before printing, make sure that the oscilloscope stops collecting data and the printer is properly connected. Click [File], then select [Print] from the pull-down list. See Fig. 3-17.


Fig.3-17 <6> Show / hide the Grid Click [File]>[Grid] button to show/hide grid. See Fig. 3-18.

Fig.3-18


<7> Display and Clear cached waveforms This osicilloscope stores 10 pages of cached waveform data. While in data collection stop mode, click [File], and then choose [Pre Pg.]/[Next Pg.]/[Empty] from the pull-down menu to operate the cached data. See Fig. 3-19.

Fig.3-19 3.3.5 System settings

Click [System] to enter system settings interface, similar to Fig. 3-20:


Fig.3-20 Button description: [Show Desktop]: to return to main menu screen [Wi-Fi setting]: to configure Wi-Fi connection [Version]: display the version information [Exit program]: to exit this program

View version information In main menu, click [System], and then select [Version] to view the current version of the oscilloscope. See Fig. 3-21.


Fig.3-21

3.3.6 View help file

In main menu, click [Help] to enter a screen similar to Fig. 3-22.

Fig.3-22



1. Distributor ignition system i.e. contact breaker withcontact-controlled ignition system (commonly known as theplatinum) and contact breaker with noncontact-controlledignition system combined with magnet, hall components orinfrared.

2. Independent ignition system: crankshaft sensor send out theignition timing signal and cylinder identification signal so that theignition system can send out ignition signal to specified cylinderin specified time, each cylinder has its independent ignition coil.

3. Simultaneous ignition system: two cylinders share one ignitioncoil, when two cylinder pistons reach top dead center at thesame time (one is compression, another is the exhaust), twospark plugs will be ignited at the same time, at this time, theignition for the former cylinder is in high-pressure lowtemperature gas mixture, the ignition is valid, while for the latterone is in low-pressure high temperature exhaust gas, the


ignition is invalid.

X-431 GDS can test and analyze the primary/secondary signal for various engine ignition systems.

In main menu, click "Engine ignition waveform" - "Configuration" to enter the interface shown as Fig. 4-1:

Fig.4-1

This interface includes six engine ignition analyses: Primary-Distributor ignition, Primary-Simultaneous ignition, Primary-Direct ignition, Secondary-Distributor ignition, Secondary-Simultaneous ignition, and Secondary-Direct ignition.

4.1 Primary-distributor ignition analysis

Tips: Generally, the sequence of ignition is (The specific sequence is


subject to the actual engine ignition sequence)

Four-stroke in-line four-cylinder: 1—2—4—3, or 1—3—4—2 Four-stroke in-line six-cylinder: 1—5—3—6—2—4, or 1—4—2—6—3—5 Four-stroke in-line eight-cylinder: 1—8—4—3—6—5—7—2 Five-cylinder: 1-2-4-5-3

V 6 engine: generally speaking, based on the person sitting on the driver cab, if the right side cylinder numbers on the right side, from the front to the back are as follows: 1, 3, 5; and the cylinder numbers on the left side, from the front to the back are as follows: 2, 4, 6; then the ignition sequence is: 1－4－5－2－3－6. If the cylinder numbers on the right side, from the front to the back are as follows: 2, 4, 6; and cylinder numbers on the left side, from the front to the back are as follows:1, 3, 5; then the ignition sequence is: 1－6－5－4－3－2.

The Figure 4-2 shows the normal ignition waveform of distributor ignition system, the upper one is the secondary waveform, the lower one is the primary waveform.

The section A is the opening of contact point; section B is the closing of contact point, during which the ignition coil is charing.


Fig.4-2 1) Contact break point: the primary circuit of ignition coil cut off, the

secondary voltage was sensed and increased sharply2) Ignition voltage: secondary coil voltage overcome the damper of

high voltage line, the contact breaker gap and the spark plug gapto release magnetizing energy, 1-2 section is the breakdownvoltage;

3) Spark voltage: For the capacitor discharge voltage;4) Ignition voltage pulse: For the charge and discharge sections;5) Spark line: The inductance discharge process, i.e. the mutual

inductance voltage of ignition coil maintains the conduction ofsecondary circuit;


6) Contact point close: The current flow into primary coil, theprimary coil oscillates due to the mutual inductance.

Primary ignition waveformSection a shows the voltage oscillation on the primary circuit due to the magnetic induction of spark in the duration; Section b shows the damped oscillation generated by remaining magnetic field energy after the spark; Section c shows the period of primary coil charging. Seen from the waveform, the amplitudes of breaker contact closed angle, break angle and breakdown voltage and spark voltage are very clear, besides, the spark delay period and two oscillations can also be tested. For the ignition system without faults, compared with the whole cycle, the contact closed angle just 45%-50% (four-cylinder), 63%-70% (six-cylinder), or 64%-71% (eight-cyliner); the breakdown voltage is over 15kv; the spark voltage is about 9kV, the spark period is greater than 0.8ms. If these values or waveform are abnormal, it means there is fault or the system needs to be adjusted.

4.2 Primary-simultaneous ignition analysis

The Figure 4-3 below shows the valid and invalid ignition waveforms. Under the working status of valid ignition, the breakdown voltage and spark voltage are higher due to the cylinder was filled fresh combustible mixture gas, which has a lower ionization level; vice versa; the above-mentioned shall be distinguished during testing.


Fig.4-3

4.3 Primary-direct ignition analysis The Figure 4-4 shows the normal secondary (the upper one) and (the lower one) primary ignition waveform of direct ignition system. Beause the on/off of primary circuit is not opening/closing of mechanical contact, but the conduction of transistor. The primary voltage has no obvious oscillations within the duration, but the voltage increases during the magnetization process due to current limiting, and this change can cause corresponding fluctuations of secondary voltage line as a result of induction of ignition coil.


Fig.4-4

4.4 Secondary-distributor ignition analysis

Connections: Plug the BNC end of secondary ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox, then connect the high-voltage clip to high-voltage line, and crocodile clips to ground. After properly connected, power on and confirm the cylinder number and ignition sequence, the interface will be shown as Figure 4-5:


Fig.4-5 Tips: Common ignition sequence (the specific sequence is subject to the actual engine ignition sequence) Four-stroke in-line four-cylinder: 1—2—4—3, or 1—3—4—2 Four-stroke in-line six-cylinder: 1—5—3—6—2—4, or 1—4—2—6—3—5 Four-stroke in-line eight-cylinder: 1—8—4—3—6—5—7—2 Five-cylinder: 1-2-4-5-3 V 6 engine: generally speaking, based on the person sitting on the driver cab, if the right side cylinder numbers on the right side, from the front to the back are as follows: 1, 3, 5; and the cylinder numbers on the left side, from the front to the back are as follows: 2, 4, 6; then the ignition sequence is: 1－4－5－2－3－6. If the cylinder numbers on the right side, from the front to the back are as follows: 2,


4, 6; and cylinder numbers on the left side, from the front to the back are as follows:1, 3, 5; then the ignition sequence is: 1－6－5－4－3－2. The Figure 4-6 below shows the normal ignition waveform of distributor ignition system, the upper one is the secondary waveform, and the lower one is the primary waveform.

The secondary waveform: A section is contact open period; B section is make contact period, which is the magnetizing field of ignition coil.

Fig.4-6


1) Contact break point: the primary circuit of ignition coil cut off, thesecondary voltage was sensed and increased sharply

2) Ignition voltage: secondary coil voltage overcome the damper ofhigh voltage line, the contact breaker gap and the spark plug gapto release magnetizing energy, 1-2 section is the breakdownvoltage

3) Spark voltage: For the capacitor discharge voltage4) Ignition voltage pulse: For the charge and discharge sections5) Spark line: The inductance discharge process, i.e. the mutual

inductance voltage of ignition coil maintains the conduction ofsecondary circuit

6) Contact point close the current flow into primary coil, the primarycoil oscillates due to the mutual inductance.

Primary ignition waveformSection a shows the voltage oscillation on the primary circuit due to the magnetic induction of spark in the duration; Section b shows the damped oscillation generated by remaining magnetic field energy after the spark; Section c shows the make contact magneting period of primary coil. Seen from the waveform, the amplitudes of breaker contact closed angle, break angle and breakdown voltage and spark voltage are very clear, besides, the spark delay period and two oscillations can also be tested. For the ignition system without faults, compared with the whole cycle, the contact closed angle just 45%-50% (four-cylinder), 63%-70% (six-cylinder), or 64%-71% (eight-cyliner);


the breakdown voltage is over 15kv; the spark voltage is about 9kV, the spark period is greater than 0.8ms. If these values or waveform are abnormal, it means there is fault or the system needs to be adjusted.

4.5 Secondary-simultaneous ignition analysis Connections: Plug the BNC end of secondary ignition pickup into CH1/CH2/CH3/CH4 channel of Scopebox, then connect the high-voltage clip to high-voltage line, and crocodile clips to ground. Connection as shown in figure 4-7：

Fig.4-7 After properly connected, power on, the interface of


secondary-simultaneous ignition will be shown as Figure 4-8.

Fig.4-8



Fig.4-9

4.6 Secondary-direct ignition analysis

Connection： 1) When the high-voltage wire is exposed, plug the BNC end of

secondary ignition pickup into CH1/CH2/CH3/CH4 channel ofScopebox, then connect the high-voltage clip to high-voltage line,and crocodile clips to ground.

2) If no high-voltage wire exposes, dismantle ignition coil of testedcylinder and use direct ignition extension cord. Connect one endto ignition coil which should be grounded via direct ignitiongrounding wire, and insert the other end into cylinder to joint withspark plug. Then plug the BNC end of secondary ignition pickupinto CH1/CH2/CH3/CH4 channel of Scopebox, then connect thehigh-voltage clip to high-voltage line, and crocodile clips to


ground. Connections are shown in Fig. 4-10:

Fig.4-10

The secondary direct ignition interface is shown as the following Fig. 4-11.


Fig.4-11

Fig. 4-12 shows the normal secondary (the upper one) and (the lower one) primary ignition waveform of direct ignition system. Beause the on/off of primary circuit is not opening/closing of mechanical contact, but the conduction of transistor. The primary voltage has no obvious oscillations within the duration, but the voltage increases during the magnetization process due to current limiting, and this change can cause corresponding fluctuations of secondary voltage line as a result of induction of ignition coil.


Fig.4-12

4.7 Waveform analysis mode

The ignition secondary single-cylinder waveform test is mainly used to: a. Analyze the ignition dwell angle of single cylinder.(ignition coil

charging time)

b. Analyze the capability of ignition coil and secondary hightension circuit (from ignition line to ignition voltage line).

c. Find the improper mixture A/F ratio of single cylinder (fromcombustion line).

d. Analyze the capability of capacitance (platinum or ignition


system).

e. Find the spark plug that causes misfire of the cylinder (fromcombustion line).

This test can provide very meaningful information about the combustion quality for each cylinder. If necessary, this test can also be performed during driving. Since the secondary ignition waveform is significantly affected by different engines, fuel systems and ignition conditions, it is useful for detecting the faults of engine mechanical parts, fuel system components, and ignition system components. Different parts of the waveform can specify that some components and systems on the specific cylinder have faults. Refer to the instructions for various parts of waveform for the related component working status of specific waveform section.


Waveform results: observe the ignition coil at the beginning of charging, the relative consistent falling edge represents the dwell angle and ignition timing of each cylinder are precise.


Ignition line: Observe the height consistence of flashover voltage. Too high flashover voltage (even out of the oscilloscope screen) represents a high resistance existed in the ignition secondary circuit (for example, open circuit, or damaged spark plug or high voltage line, or too large time gap on spark plug), while the too short sparking voltage represents the resistance of ignition secondary circuit is lower than normal value (due to pollutant and broken spark plug or the high voltage line of spark plug has electrical leakage, etc.).


Combustion line: Observe the spark or the combustion line which shall be clean with few clutter, as lots of clutter indicates the cylinder has poor ignition due to ignite too early, damaged nozzle, pollutant spark plug, or other reasons. The duration of combustion line indicates the mixing ratio of the cylinder is abnormal lean or rich. Too long combustion line (usually greater than 2ms) represents the mixing ratio is rich, whereas too short of combustion line (usually less than 0.75ms) represents the mixing ratio is lean.



Primary voltage analysis According to the faulty primary voltage waveform collected by the ignition analysis, the related components and mechanical equipment status of ignition system electrical circuit can be analyzed, which provides a reliable basis for the adjustment and maintenance of power circuit to avoid the blind demolition.

The waveform shown on Fig. 4-13, appears a lot of clutter on the contact break point, which is obviously caused by the serious erosion on contact break point. It can be verified via burnishing the contact or changing the circuit breaker.

Fig 4-13 For the primary voltage waveform shown on Fig. 4-14, the damped attenuation cycles obviously reduced on the spark period, the


amplitude became lower, which is evidently caused by capacitor leakage.

Fig 4-14 The waveform on Fig. 4-15, shows the accidental pumping during contact closing period. The irregular beating is caused by insufficient spring force.

Fig.4-15 The curve on Fig. 4-16 shows the contact angle is too small during the magnetizing period, which is caused by too large contact gap.


Fig.4-16 A lot of clutter will be displayed on the horizontal section of primary waveform if contact has poor grounding, as shown below figure 4-17.

Fig.4-17 Fig. 4-18 shows the fault of low-voltage waveform in electronic ignition system. The voltage does not rise during magnetizing, which indicates that the effect of limitation of the circuit failed and no components on distributorless ignition system can be adjusted. When this waveform is abnormal, you can only replace the ignition coils, igniter, ignition signal generator and cam position sensor, etc., one by one, to find out the faulty component or module.


Fig.4-18 The secondary waveform is also affected by the spark plug, the combustion process, mixture gas composition, the engine thermal state of the ignition coil, etc., which is more complicated. The following lists a large number of measured secondary faulty waveform for reference. Since various factors lead to the failures, Fig. 4-19 just shows the major possible factors for the failures.



Fig.4-19

Date post:	30-May-2020
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