Hi-Scan Pro Utilization (EMS Diagnosis Manual)

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Hi-Scan Pro Utilization

Hi-Scan Pro Utilization (EMS Diagnosis Manual)

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Contents

1. Crankshaft Position Sensor Signal Analysis

2. Camshaft Position Sensor Signal Analysis

3. TPS Signal Analysis

4. Air Flow Sensor Signal Analysis

5. O2 Sensor Signal Analysis

6. Injector Signal Analysis

7. ISC Valve Signal Analysis

8. Air Temp. Sensor Signal Analysis

9. Knock Sensor Signal Analysis

10. Vehicle Speed Sensor Signal Analysis

11. EGR Valve Signal Analysis

12. Purge Valve Signal Analysis

13. O2 Sensor Heater Signal Analysis

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About Sensor Crankshaft position sensor is a sensor for locating piston by ECM and necessary to find

ignition time .If the signal of the Crankshaft position sensor keeps its consistency, then it is hard to find starting and ending point. Therefore, two teeth are taken out from the crank and it is called Long Tooth and the rest are called Short Tooth. By using long Tooth, TDC ( Top Dead Center ) is found.

Contents shown by signal of crank sensor.1. Ignition time = 360deg * Number of tooth before TDC / Number of tooth at one revolution of engine. Ignition time is calculated by number of tooth between the long tooth and peak voltage. Peak voltage is obtained by measuring signal of Crankshaft Position sensor and primary ignition wave simultaneously.2. Engine speed (RPM) = 60 / ( Time between long tooth * Number of long tooth at one revolution of engine) RPM is calculated by number of long tooth at one revolution of engine.

1.1 Introduction of Crankshaft position sensor and principle (1/2)

1. Crankshaft position sensor(CKP) signal analysis

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Sensor type

AlgorithmThis sensor is the most important sensor for the ECM. If sporadic engine stall happened , then suspect this sensor at first.

1. If the ECM detects fault on this signal, then the ECM stop “fuel injection and ignition

2. If the ECM could not detect fault signal, then normal component or not equipped component might be detected as a fault one.

Three mostly used Crankshaft position sensor.

1. Optical Sensor : The sensor is used on a single-bodied cam shaft with a hole on the disk. The signal is recognized when the signal passes through the hole while the disk is revolving. This particular sensor is destructive by heat and humidity and makes lots of noise. ( This is the only sensor that disk for Crankshaft position sensor revolve 1 revolution while crank shaft rotate 2 revolution. )

2. Magnetic Sensor : If the electromagnetic power generated by coil is intercepted by revolution of a single-bodied camshaft with target wheel (normally outside of flywheel ), then the voltage is generated. The sensor is using this voltage for signal..

3. Hall type sensor : The circuit is included in the sensor inside. This sensor electron The circuit included inside the sensor discharge the electron. The single bodied crank shaft with target wheel (normally outside of fly wheel ) disturbs discharging of electron and generate the voltage. This voltage is used for signal.

Magnetic type sensor signal

1. 2 Introduction of Crankshaft position sensor and principle (2/2)

Optical type

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Hi-Scan Mode : Please perform following procedure on the screen, - Vehicle selection System(Engine / Transmission / ABS …)Crankshaft Position Sensor Measuring

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be

connected with ground line of sensor.

1.3 The Methodology of Crankshaft Position Sensor Signal Measurement

Sensor repair info view.

Normal value About sensor Data analysis

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Malfunction of Crankshaft Position Sensor (1/2)

Cause of trouble 1. Malfunction of Crankshaft Position sensor or wiring circuit failure

(Signal, Ground and Reference line)2. Bad connection of wiring3. Cut off noise or remove cause of noise from Crankshaft Position sensor 3.1 Shield Crankshaft Position sensor wiring. 3.2 Check whether spark plug is original part or not (Resistance range : 2.0 - 4.5K)4. The counteraction of sensor maker should be required.

Engine state 1. The engine is not started.

2. Vibration? Stall in the engine sometimes occur.3. Vibration? Stall in the engine sometimes occurred and display DTC of normal part or non existing part4. The ignition timing is out of control range

Normal signal

Troubles

1. The signal is always high or low.2. The signal is intermittently missed.3. The noise signal detection.4. The signal is normal but ECM identify wrong Crankshaft Position signal.

1.4 Crankshaft Position Sensor Trouble type and Analysis (1/2)

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Malfunction of Crankshaft Position Sensor (2/2)

Signal wave when trouble detection

1. Always constant signal 2. Intermittently signal missing

3. The noise signal detection

4. Signal is normal but ECM wrong identification

Ignition timing from scanner is different with calculation from signal.

1.5 Crankshaft Position Sensor Trouble type and Analysis (2/2)

TDC

ATDC 48deg

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1. Field example of Crankshaft Position sensor trouble : ECM wrong identification

Cause of trouble

ECM identified wrong Crankshaft Position signal and it led to wrong calculation of ignition timing. So, ECM started ignition with suction stroke.

Related vehicles

This phenomenon is frequently occurred with magnetic Crankshaft Position sensor.Accent 2000MY, Elantra/Lantra, Coupe

Signal view

TroubleAccent 1.5L SOHC vehicle is started with hesitation.

Ignition was BTDC 12deg on scanner but calculation from measured signal was ATDC 48deg. TDC position was identified from service information of Hi-Scan.

1.6 Crankshaft Position Sensor Field Service Example (1/2)

TDC

ATDC 48deg

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2.Field example of Crankshaft Position sensor trouble : Intermittent signal missing

Cause of trouble Crankshaft Position signal was abnormal due to power cut when key released.

Related vehicles

This phenomenon is frequently occurrs with the optical Crankshaft Position sensorEF sonata, XG Grandure etc.

Signal view

Trouble HMC Sonata Trajet XG vehicle : Vehicle starts with hesitation in cold ambient condition or does not start at all.

If you measure Crankshaft Position signal with above phenomenon, you can see an abnormal crank signal. It result in injection cut off.

1.7 Crankshaft Position Sensor Field Service Example (2/2)

Cracked part

No injection

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About Sensor

Camshaft Position sensor is a sensor that indicate the TDC of each cylinders by the ECM. This sensor is necessary to calculating injection phase. We can calculate the TDC from the Crankshaft Position sensor but cylinder number. Therefore ECM recognize the TDC right after Camshaft Position signal. The ECM use the cam signal located between two long tooth. If the signal of cam is located inside the long tooth, then The ECM detects it as a fault.

Information from the signal of cam sensor : TDC of the1st cylinder

2.1 Introduction of Camshaft Position sensor and principle(1/2)

2. Camshaft Position sensor signal analysis

19th

TDC

TDC shown after CAM signal is the first TDC. 19th

TDC

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About Sensor

Algorithm In order to reduce the emission, injection should be finished before intake valve open. If the fuel is injected on the hot intake valve, then fuel is well vaporized and this helps good combustion.

Therefore, cam signal is used to identify the cylinder number.

In case of no spark time adjustment type,we can know it by comparing cam signal position with Crankshaft Position sensor.

Three mostly used Camshaft Position sensor.

1. Optical Sensor : The sensor is used on a single-bodied cam shaft with a hole on the disk. The signal is recognized when the signal passes through the hole while the disk is revolving. This particular sensor is destructive by heat and humidity and makes lots of noise. ( This is the only sensor that disk for Crankshaft Position sensor revolve 2 revolution while crank shaft rotate 1 revolution. )

2. Magnetic Sensor : If the electromagnetic power generated by coil is intercepted by the revolution of a single-bodied camshaft with a target wheel (normally outside of the flywheel ), then the voltage is generated. The sensor use this voltage for signal.

3. Hall type sensor : The circuit is included in the sensor. This sensor electron The circuit discharge the electron. The single bodied crank shaft with a target wheel (normally outside of fly wheel ) disturbs discharging of the electron and generates the voltage. This voltage is used for signal

Optical / hall type sensor signal

Magnetic type sensor signal

2.2 Introduction of Camshaft Position sensor and principle(2/2)

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How to connect sensor : Channels A and B can be used simultaneously. The plus of probe(Red color) should be connected to the signal line of sensor and the minus(black color) should be con

nected to the ground line of the sensor.

2.3 The Methodology of Camshaft Position Sensor Signal Measurement

Remark :

Since both A and B channels can be used at the same time, it is better to measure crank and Camshaft Position signal simultaneously.

Sensor repair info view

Normal valve About sensor Data analysis

Hi-Scan Mode : Please perform following procedure on the screen, - Vehicle selectionSystem(ENG)CAM Part(F4 key) Measuring

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Malfunction of Camshaft Angle Sensor(1/2)

Cause of trouble

1. Malfunction of Camshaft Position sensor or wiring circuit failure (Signal, Ground and Reference line)2. Check valve timing. If it is not proper, please adjust it.3. Cut off noise or remove cause of noise from Camshaft Position sensor 3.1 Shield Camshaft Position sensor wiring. 3.2 Check whether spark plug is original (or not) (Resistance range : 2.0 - 4.5K)

Engine state 1. The engine problem is not occurred but GDI engine is not started.

2. CAM sensor error is intermittently detected with poor acceleration.3. The engine vibration and stall are sometimes occurred and display DTC of normal part or non existed part4. The ignition timing is out of control range.

Normal signal

Trouble1. The signal is always high or low.2. The signal is intermittently missed(Invalid signal detection during 1 cycle).3. The noise signal detection.

2.4 Camshaft Angle Sensor Trouble type and Analysis (1/2)

Upper signal in picture is CAM signal and sine signal is crank signal.

Camshaft Position signalCrankshaft Position sensor signal

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Malfunction of Camshaft Angle Sensor (2/2)


1. Always constant signal

2. Intermittently signal missing

(CAM signal detection in long tooth duration:This is normal with Avante XD)


2.5 Camshaft Angle Sensor Trouble type and Analysis (2/2)

CAM must appear between long teeth

No Camshaft Position signal Camshaft Position signal

CAM must appear between long teeth

CAM signal is inside of long tooth (Bad timing adjustment)

Avante, XG use this signal

CAM signal should locate about 2 teeth before long tooth.

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Field example of Camshaft Position sensor trouble : Case of CAM signal delay

Cause of trouble

Ignition was retarded (about 9[deg]) due to wrong valve timing and CAM signal was detected just before long tooth.

Related vehicles This phenomenon is occurred when CAM signal is identified before long tooth.

Signal view

TroubleElantra / Lantra vehicle is not accelerated and CAM error is sometimes detected.

CAM signal was identified before long tooth but distance between CAM signal and long tooth was not over 1 tooth.

The valve timing was wrong adjusted as 1 tooth.

< Reference > The valve timing can be fast or delay by tensioner moving when

acceleration

2.6 Camshaft Angle Sensor Field Service Example

Before valve timing adjustment After valve timing adjustment

CAM signal is close to long tooth

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About Sensor

TPS is the sensor to find out how much the acceleration pedal accelerates. If the line of this sensor is broken, then more than 4.7V or 2.1V of constant signal voltage can be produced depending on ECM internal circuit..

TPS

3.1 Introduction of TPS and principle

Sensor type

Algorithm In order to response to the driver’s will quickly, fuel injection is controlled by the acceleration speed and pedal value. If the pedal value is more than 50%, then the oxygen sensor feedback control is stopped to control the engine with more torque.

In case of sensor failure, intake air sensor is substituted for TPS. Therefore, fast accel and decel can not be detected with sensor failure and hesitation can occur.

Wiper type is the mostly used signal sensing type by now.

3. Throttle Position Sensor (TPS) signal analysis

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How to connect sensor : Channels A and B can be used simultaneously. The plus of probe(Red color) should be connected to the signal line of the sensor and the minus(black color) should be c

onnected to the ground line of sensor.

3.2 The Methodology of TPS Signal Measurement

Remark :

As it is possible to use A,B channels at the same time, it is better to measure TPS and intake air flow simultaneously.

Hi-Scan Mode : Please perform following procedure on the screen, - Vehicle selectionSystem(ENG)TPS Part(F4 key) Measuring

Normal valueAbout Sensor Data analysis


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Malfunction of TPS (1/2)

Cause of trouble

1. Malfunction of throttle position sensor or wiring circuit failure (Signal, Ground and Reference line)2. Check ground line and connecting part. If there is something wrong, connect it correctly. If it is occurred again after repairing, ECM should be changed with latest version. 3. Remove cause of noise 3.1 Shield sensor signal line. 3.2 Check whether spark plug is original part or not(Resistance range:2.0-4.5K)

Engine state

1. The vehicle hesitation is occurred with acceleration.2. Idle TPS adaptation value is less than TPS absolute value at normal idle and ECM doesn’t idle state even if real idle.Engine vibration is occurred with this phenomenon. 3. Emission is increased.4. The vehicle hesitation and vibration are occurred with acceleration.

Normal signal

Trouble1. The signal is always high or low.2. The signal is intermittently missed(Micro cut-off occurrence).3. The noise signal detection.4. Even if idle state, ECM does not identify it.

3.3 TPS Trouble type and Analysis (1/2)

As can as possible, TPS signal should be compared with MAF sensor signal. And check whether TPS & MAF signal are increased at the same time when acceleration.

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Malfunction of TPS (2/2)

Signal wave when

trouble detectio

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1. Always constant signal

2. Intermittently signal missing (Micro cut-off occurrence)


3.4 TPS Trouble type and Analysis (2/2)

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1.Field example of TPS malfunction : Signal missing by micro cut off

Cause of trouble

TPS signal is cut off.

Related vehicle This phenomenon is occurred in HMC vehicle which TPS ground line is connected

with ECM outside ( Accent 1.3/1.5L DOHC etc )

Signal view

Trouble Accent 1.3L SOHC vehicle not only doesn’t identify idle state but also vibration and stall are occurred. The hesitation is occurred with acceleration and scanner doesn’t recognize idle state even if vehicle is real idle.

TPS signal is sometimes “0” with normal MAF sensor signal.

3.5 TPS Field Service Example (1/2)

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2. Field example of TPS malfunction : Signal noise occurrence.

Cause of trouble As connecting TCU, TPS signal noise is so much detected. ECM identify noise as

fast acceleration, so it result in over fuel enrichment.

Related vehicle Vehicles which use same TPS wiring from TCU and ECM

Signal view

TroubleThe emission is increased so much in idle state with Tiburon 2.0L vehicle. O2 sensor is normal feedback control but it is shifted to rich side.

TPS signal noise is so much detected “0” with normal MAF sensor signal.

3.6 TPS Field Service Example (2/2)

Signal view

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About Sensor This is the sensor to see how much air flow is coming into the cylinder. It is very

important to calculate injection time. If the line is broken, then there are occasions when output voltage is over 4.7V depending on internal circuit like TPS.

4.1 Introduction of Intake Air Flow Sensor and Algorithm

Sensor type

Algorithm

The fuel quantity is decided by the air flow and the injector opening time decides fuel quantity. The calculated fuel amount is compensated more precisely by oxygen sensor feedback compensation. In case of air flow sensor error, the substitute value is calculated by engine speed and TPS.

4. Intake Air Flow Sensor Signal Analysis

Mostly used sensors by now are the MAP sensor ( Intake manifold pressure check ), MAF (Mass Air Flow :the resistance is changed when heated tip is cooled by inducted air )and Karman Vortex (This sensor monitors vortices generated as the intake air flows past vortex generators. Air flow is calculated by the frequency of ultrasonic waves that are changed depending on the amount of vortices. )

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4.2 The Methodology of Air Flow Sensor Signal Measurement

Remark :

As it is possible to measure A,B channels, it is better to measure intake air flow and TPS simultaneously.



Hi-Scan Mode : Please perform following procedure on the screen, - Vehicle selectionSystem(ENG)MAP Part(F4 key) Measuring

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Malfunction of Air flow sensor

Cause of trouble

1. Malfunction of air flow sensor or wiring circuit failure (Signal, Ground and Reference line)2. Check ground line and connecting part.If there is something wrong,connect it.

Engine state

1. Engine is hard to start. Even if it is started, vehicle hesitation is occurred when acceleration 2. Intermittently vehicle hesitation or engine stall is taken place.

Normal signal

Trouble 1. The signal is always high or low.2. The signal is intermittently constant.

4.3 Air Flow Sensor Trouble type and Analysis

As can as possible, MAF signal should be compared with TPS signal. And check whether MAF and TPS signal are increased at the same time when acceleration.

Signal wave when

trouble detectio

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As can as possible, MAF signal should be compared with TPS signal. And check whether MAF and TPS signal are increased at the same time when acceleration.

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Field example of Air flow sensor malfunction :Abnormally high signal (Sensor is normal but signal is high)

Cause of trouble

High MAP signal was detected because internal EGR was increased by exhaust pipe blocking. Due to that, ECM identify big air flow and exhaust pressure make high. It led to over fuel enrichment and poor acceleration due to lack of power.

Related vehicle

In case of MAP equipped vehicles,if exhaust pipe is blocked,this phenomenon is always occurred. MAP signal is increased proportion to exhaust pipe blocking status.

Signal view

Trouble Scoupe 1.5L SOHC vehicle is hard to start. Even if it is started, power is lack with acceleration and exhaust gas is black color.MAP signal is very high in idle state but scanner identify normal idle state.

Signal(1.9volt) is slightly higher than signal of no load racing(0.8 - 1.5volt)

4.4 Air Flow Sensor Field Service Example

Intake air flow signal

Normal : 1.1V at idle

Abnormal : 1.85V at idle

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About SensorThis is the sensor to compensate the fuel injection to get the stoichiometric air fuel ratio (14.6). The different voltage is generated depending on fuel richness ( oxygen richness ). According to this voltage variation, fuel injection is added or subtracted so that always relevant fuel is injected.

5.1 Introduction of oxygen sensor and principle

Sensor type

Algorithm

Oxygen sensor produce below 0.5V with rich oxygen( lean fuel) and over 0.5V with lean oxygen (rich fuel). Using this, ECM inject more fuel when oxygen sensor voltage is below 0.5V and reduce fuel as soon as voltage is over 0.5V. By continuing this control, supplied fuel is getting close to stoichiometirc air fuel ratio. This is the feedback control. In case of sensor failure, fuel is supplied by basic calculation.

Mostly used sensor now is the Zirconia ( It generate the voltage from 0V to 1V by oxygen richness ), Titania ( It generate different resistance by oxygen richness ) and UEGO sensor ( It is used for lean burn engine and it generate different current by oxygen richness ). Titania and Zirconia sensors are classified with and without heater.

5 Oxygen sensor signal analysis

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5.2 The Methodology of O2 Sensor Signal Measurement

Remark :

As it is possible to measure A,B channels, it is better to measure TPS too.


Hi-Scan Mode : Please perform following procedure on the screen, - Vehicle selectionSystem(ENG)O2 sensor Part(F4 key) Measuring

Normal value About Data analysis

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Malfunction of O2 sensor

Cause of trouble

1. Malfunction of O2 sensor or wiring circuit failure (Signal, Ground and Reference line)2. Check ground line and connecting part.If there is something wrong,connect it.3. A/F ratio distribution is unstable with individual cylinder (Fuel gas is induced from outside)4. O2 sensor tip is poisoned or exhaust gas temperature is too low.

Engine state

1,2 If acceleration pedal is worked before engine warm-up before, engine stall is occurred or power is lack. And also vehicle hesitation is taken place when fast acceleration. 3. Engine vibration is severe. In case of knock sensor equipped, power is lack and fuel economy make bad due to knock detection.4. Engine stall is Sometimes occurred or exhaust gas is black with fast acceleration.

Normal signal

Trouble1. The signal is always high or low.2. The signal is intermittently constant3. The switching is too fast.4. The switching is too slow.

5.3 O2 Sensor Trouble type and Analysis

As can as possible, O2 sensor signal should be compared with TPS signal. And check whether O2 sensor signal is switched or not when acceleration. If signal is switched, O2 sensor is normal.


1. Always constant 2. Slow switching 3. Fast switching

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1. Field example of O2 sensor malfunction : Too fast signal switching

Cause of trouble Vibration and knocking is decreased after repairing hydro tappet but it is still

remained. It is cleared as using synthetic oil.

Related vehicle

Most vehicles are related, especially it is so much taken place when low quality is used during long time.(In case of solid tappet equipped engine,if tappet is not adjusted,it is occurred)

Signal view

TroubleAccent 1.5L SOHC vehicle vibration is severe in idle state and heavy knocking is detected. O2 sensor signal is rapidly switched(Repeat high and low).

In case of too fast signal switching, it is due to abnormal tappet opening and canister closing etc.

5.4 O2 Sensor Field Service Example (1/2)

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2. Field example of O2 sensor malfunction : Too slow signal response

Cause of trouble Due to insufficient O2 sensor light off, signal is low and ECM start feedback control at this ti

me. ECM identify that fuel is lean with low signal and it result in over fuel enrichment.

Related vehicle

This phenomenon is frequently occurred with optical Crankshaft Position sensor (MELCO 52 pin ECM).Elantra, Scoupe, Excel(1.5L SOHC), New sonata(1.8, 2.0L SOHC) etc.

Signal view

TroubleElantra 1.5L SOHC vehicle hesitation or stall is taken place with acceleration after idling. At this time exhaust gas is black color and acceleration is poor.

Signal is stayed around 0.4 volt when problem occurrence. If acceleration pedal is continuously worked, signal is bigger and bigger as below picture by exhaust temperature.

5.5 O2 Sensor Field Service Example (2/2)

< Counter action >

O2 sensor is exchanged with heated type.Signal and ground line make connection same as before. And heater line is connected with after main relay and always operated with engine start. After this working, spark plug should be changed with new one and drive with high speed(2hours) to remove carbon in combustion chamber.

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About Injector The fuel quantity is decided by the air flow and the injector opening time decides fuel

quantity. The injector open by electromagnetic power and close by spring force. Since the electromagnetic power is depending on battery power, injector opening time is compensated by battery power.

6.1 Introduction of Injector and principle

Injector type

Algorithm

If the signal of Crankshaft Position sensor has the noise or broken signal, ECM stop the fuel injection until it get normal signal of Crankshaft Position sensor.

Therefore, engine can be unstable or stall.

The principles of opening ( open by electromagnetic power and close by spring force )are mostly same. But it is classified into orifice and pintle type by injection hole.

6 Injector active signal analysis

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6.2 The Methodology of Injector Signal Measurement



Hi-Scan Mode : Please perform following procedure on the screen, - Scope meter Engine Actuator Injection Measuring

.



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Malfunction of Injector

Cause of trouble 1. Wiring circuit failure (Power supply and Ground line)

2. Crankshaft Position sensor noise detection 3. Carbon accumulation in combustion chamber or fuel filter problem by other materials.

Engine state

1. Vehicle vibration is severe after start. 2. Vibration or engine stall is intermittently occurred. 3. Vehicle vibration is severe and engine sound is loud.

Normal signal

Trouble1. Injector is not opened.2. Intermittently injector is not opened.3. The clogging of injector.

6.3 Injector Trouble type and Analysis

Peak voltage and injector opening time is equal to individual cylinder without acceleration pedal.


1. Always constant 2. Injector is not opened 3. Clogging of injector

In case of clogging of injector or taking out from engine, it can be checked by O2 sensor signal.

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1. Field example of Injector malfunction : Clogging of injector tip

Cause of trouble Valve overlap is too big (55 deg). Carbon make clogging of injector.

Related vehicle

Most vehicle which has big valve overlap and use injector exception pintle type make this phenomenon.

Signal view

TroubleTiburon 2.0L DOHC (Camshaft modified vehicle): Checked O2 sensor signal due to severe engine vibration. O2 sensor signal switching is too fast.

Abnormal O2 sensor signal. It is due to abnormal A/F distribution with individual cylinder. Fuel is not supplied in a certain cylinder.

6.4 Injector Field Service Example (1/2)

Even if injector is clogged, injector signal is normal on scanner.

Fuel vapor gas flow in

Normal signal

Signal switching is too fast

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2.Field example of Injector malfunction:Sometimes not opened injector

Cause of trouble

Abnormal Crankshaft Position signal is detected due to noise detection, so ECM cut off fuel injection . At this time problem is taken place.

Related vehicle

This phenomenon is occurred with optical or magnetic type Crankshaft Position sensor.

Signal view

TroubleNew sonata (MAP sensor) vehicle vibration is intermittently occurred and engine stall. This is not taken place regularly.

O2 sensor signal is mainly below 0.5 volt(lean shift) but sometimes show above 0.5 volt(rich shift).

6.5 Injector Field Service Example (2/2)

< Counter action > Shield Crankshaft Position sensor signal line to prevent noise.

We don’t know whether ECM identify noise detected Crankshaft Position signal. If injector is not opened, you can think that ECM identify noise signal.

Crankshaft Position sensor

Shield ground

Shield wireconnector

Connect shield with condenser on the body

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About ISC valve

ISC valve is the valve that bypass the air to keep constant engine speed when throttle valve is closed. ECM control only the opening of the valve and air is supplied by the under pressure in the surge tank..

7.1 Introduction of ISC valve and principle

ISC valve type

Algorithm

The ECM compare the engine speed with target speed and open or close the valve when engine speed is lower or higher than target. This compensation is composed of proportional, integral and differential term- so called PID control..

Three mostly used type are DC type controlled by DC motor, Duty type controlled by duty and Step type controlled by the electromagnet

Duty type (2 coil) Step motor type

7. ISC valve control signal analysis

Control line

ISC valve

Control line

GND Duty control

ISC valveControl line

Control line

Control line

Control line

Engine speedEngine speed Target speed

ISC valve opening

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7.2 The Methodology of ISC Valve Signal Measurement




About sensorNormal value Data analysis

Hi-Scan Mode : Please perform following procedure on the screen, - Scope meter Engine Actuator ISC Measuring

IAC valve

IAC valve

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Malfunction of ISC valve

Cause of trouble

1. Wiring circuit failure (Power supply and Ground line) or Malfunction of TR in ECM2. Wiring is normal but valve is not operated by carbon or step loss etc. (Step loss : The difference between ECM control and actual opening duty) 3. Carbon accumulation in air flow path

Engine state 1, Even if engine start is possible, it is stalled soon or severe vibration

is occurred. (In case of BOSCH ISC, engine speed is stayed around 1500rpm) 2. If it is occurred with little opening,engine vibration or stall is taken place If it is occurred with big opening, engine is stayed with high speed. 3. As soon as engine is started, it is stalled.

Normal signal

Trouble1. ISC is not opened.2. Intermittently ISC is not opened.3. The closing stuck of ISC valve.

7.3 ISC Valve Trouble type and Analysis

ISC valve signal have difference according to which type is used. (Duty type / DC motor type / Step type)


1. Always constant 2. ISC valve stuck 3.ISC valve close stuck

Although ISC valve is stuck with closed position ,signal is normal. So, it can be checked by actuator operation. “ Refer to chapter 5”

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1. Field example of ISC malfunction : Clogging of ISC valve pintle

Cause of trouble Leaking oil from turbo is mixed with carbon. It led to block ISC valve pintle.

Related vehicle

This is often occurred with duty type ISC valve equipped vehicles,especially 1 coil type is more frequent.

Signal view

TroubleScoupe 1.5L SOHC Turbo engine stall is frequently occurred and engine start is hard.

7.4 ISC Valve Field Service Example

2. Field example of ISC malfunction : ISC valve step loss

Cause of trouble

Step between ECM control and actual opening have big difference. At this time, ISC valve adaptation is abnormal and opening duty is not controlled properly. So, this phenomenon is taken place.

Related vehicle

This is occurred with step motor malfunction or aging vehicle(Above 50,000 km/h) without step motor equipped.

Signal view

TroubleNew sonata (MAP sensor) vehicle: If engine stall is occurred,it is frequently taken place.

There is no problem in ISC signal, only ISC pintle is not operated. Carbon in pintle should be cleared.

There is no problem in ISC signal, only ISC pintle is not operated. ISC valve should be cleaned after disassembling. And reset ISC adaptation value and stay idle state more than 10 minute.

This step loss is not cleared completely. Although it is repaired or exchanged with new one, it may occur later.

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About Sensor

Coolant sensor is a sensor for detecting of how much engine is heated up and necessary to control injection/ignition/ISC valve depending on engine temperature. Because engine load is surely different depending on engine temperature. Intake air temperature sensor is used to calculate exact intake air flow and necessary for MAP sensor type. But it is often not to use it with MAF(Mass air flow )type.Some of MAP sensor include intake air temperature sensor inside and it is called T-MAP sensor.

8.1 Introduction of temperature sensor signal and principle

Sensor Type

Algorithm

Intake air temperature sensor is a sensor for calculating intake air quantity more exactly. The coolant temperature sensor is to set different target of fuel(Air Fuel ratio)/target speed/spark time in accordance with coolant temperature to compensate different engine load

Intake air temp. sensor T_MAP sensor

Coolant temp. sensor

Mostly used type is a thermistor type that increase the resistance with high temperature and decrease the resistance with low temperature.

.

8. Temperature sensor signal analysis

Target lambda area without feedback control depending on coolant temp

Target ignition area depending on coolant temp. - idle status

AF range

Spark range

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8.2 The Methodology of Temperature Sensor Signal MeasurementHow to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be



Hi-Scan Mode : Please perform following procedure on the screen, - Scope meter Engine Sensor WTS Measuring


Coolant sensor Coolant sensor

Coolant sensor

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Malfunction of Temperature sensor

Cause of trouble

1. Wiring circuit failure (Signal or Ground line open or shorted) 2. ECM internal circuit malfunction or temperature sensor position is not proper.

Engine state

1. Poor acceleration or exhaust gas is black due to over fuel enrichment. It is returned normal after 10 minute. 2. Intermittently idle rpm is oscillating (800 - 1000rpm).

Normal signal

Trouble1. Signal line open circuit (Temperature is below -30 deg.C )2. Signal line short to ground (Temperature is above 127 deg.C )3. Temperature signal change is too fast.

8.3 Temperature Sensor Trouble type and Analysis

Temperature sensor signal have difference according to which type is used. (Duty type / DC motor type / Step type)


1. Always constant 2. Temp. signal rapidly change

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Field example of Temp.sensor malfunction : Fast coolant signal change

Cause of trouble

Engine speed is oscillated by coolant temperature change due to ECM internal circuit malfunction. Idle engine speed is set with ECM data by coolant temperature in ECM.

Related vehicle Siemens ECM(52 pin) has sometimes problem but other ECM may have this phenomenon.

Signal view

TroubleAccent 1.3L SOHC vehicle : Engine speed is oscillating from 800 to 1000rpm with idle state.

8.4 Temperature Sensor Field Service Example

Engine speed is changed with coolant temperature oscillating. If actual coolant temperature is constant. The problem is still remained after TCO sensor change(3ea) but it is cleared after ECM change.

If you want to measure temperature, please refer to “Chapter 4 Multi meter utilization”

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About Sensor

The knock sensor employ the piezoelectric element or silicon that produce the signal(voltage) when it gets pressure. If there is knocking in the engine, then vibration is transformed to pressure vibration and it produces voltage. According to this voltage, knocking is detected.

9.1 Introduction of knock sensor and algorithm

Sensor type

Algorithm

Therefore, this signal is sampled by hardware and knocking is detected.

But the frequency of bad engine vibration can be overlapped with frequency of knocking. So, too much knocking can be detected by engine vibration.

It is difficult to distinguish the knock sensor type by means of sensor shape. But the element to detect vibration may be different.

Knock sensor

The frequency of knocking signal is too fast(about 6 - 18Khz) to analyze it by ECM.

9. Knock sensor signal analysis

45


9.2 The Methodology of Knock Sensor Signal Measurement

Hi-Scan Mode : Please perform following procedure on the screen, - Scope meter Engine Sensor Knock Measuring

How to connect sensor : A and B channel can be used simultaneously. The plus of probe(Red color) should be connected with signal line of sensor and the minus(black color) should be connected with ground line of sensor.


Data analysisNormal value About sensor

46


Malfunction of Knock sensor

Cause of trouble 1. Wiring circuit failure (Signal or Ground line open or shorted)

or knock sensor malfunction 2. A/F is different with individual cylinder.(Refer to 2.6injector trouble)3. ECM internal circuit malfunction (Should be changed ECM)

Engine state 1.If ECM detect knock sensor error, ignition is retarded(6-12deg).

It result in lack of power and bad fuel economy. If ECM don’t detect error,ignition is not retarded even if knocking is occurred. 2 Too much ignition retard(6-12deg) make lack of power and bad fuel economy3.Same as NO.1 description.

Normal signal

Trouble1. Knocking signal is always constant (Signal line open or shorted)2. Heavy knocking detection3. Knock signal is normal but knock is not detected (Communication malfunction of knock signal in ECM)

9.3 Knock Sensor Trouble type and Analysis

Knock sensor signal have difference according to which type is used. (Duty type / DC motor type / Step type


1. Always constant 2. Heavy knocking detection

Abnormal : constant signal

Normal signal

Heavy knocking

Normal signal

47


Field example of Knock sensor malfunction : Heavy knocking detection

Cause of trouble

Cylinder #1 intake valve is not opened properly due to malfunction of #1 rocker arm operation. It result in engine vibration and ignition retard by heavy knocking detection. So, ignition retard make lack of power and bad fuel economy.

Related vehicle

In case of knock sensor equipped vehicles, if engine state is unstable, it guess knocking detection.

Signal view

TroubleTiburon 2.0L DOHC vehicle: The power is lack with driving and fuel economy is

bad.

9.4 Knock Sensor Field Service Example

This signal can be also checked with O2 sensor signal.

Knock I.C exist in ECM. If it has malfunction, knocking detection is impossible. But ECM can detect whether it properly works or not.

Knock signal with problem detection

O2 sensor signal with problem detection

Heavy knocking

Normal signal

48


About Sensor

Vehicle speed sensor is a sensor that check wheel speed per second to calculate vehicle speed. It measures speed of body of rotation that directly connected with driving shaft.

10.1 Introduction of vehicle speed sensor and principle

Sensor Type

Algorithm

Mostly used vehicle speed sensor are lead type (switch on and off at every revolution )/ magnetic type and hall type.

Vehicle speed is calculated by calculating how many voltage over the threshold(normally 1.0 - 2.5V) are generated at one second. If the noise signal is over the threshold, then it is recognized as vehicle speed.

Magnetic and hall type is same principle as Crankshaft Position sensor.

Vehicle speed signal is required for AT car to decide gear shifting level and for MT car to reduce the shock during fast acceleration by adjusting spark time and fuel depending on vehicle speed and gear level.

ECM calculates the gear level using engine speed and vehicle speed.

10. Vehicle speed sensor signal analysis

VS sensor Rotor rotate with the cable connected to driving shaft

A hole for cable connection

VS sensor(lead switch type)

49


Hi-Scan Mode : Please perform following procedure on the screen, - Scope meter Engine Sensor Vehicle Speed Measuring

Data analysisAbout sensorNormal value

10.2 The Methodology of Vehicle Speed Sensor Signal Measurement



Vehicle speed Vehicle speed

50


Malfunction of Vehicle speed sensor

Cause of trouble 1. Wiring circuit failure (Signal or Ground line open or shorted)

or vehicle sensor malfunction 2. Too much signal noise detection in vehicle speed sensor

Engine state

1. Engine RPM is slightly high in idle state and it is oscillating. 2. In case of A/T vehicle, shift point is high gear position and it is shifted with 2 or 3 gear when take off.

Normal signal

Trouble1. Any vehicle speed sensor signal is not detected with driving.2. Vehicle speed is much higher than actual speed. (Too much signal noise)3. Even though vehicle stop, ECM identify vehicle speed.

10.3 Vehicle Speed Sensor Trouble type and Analysis

Vehicle speed signal should be detected in driving. It should be always constant at vehicle stop.


1. always constant 2. Noise detection in VS signal

51


Field example of VS sensor malfunction : Signal noise detection

Cause of trouble Too much noise is detected in VS signal. ECM identify driving with high speed.

Related vehicle All vehicles (Especially in case that ECM receive VS signal from TCU)

Signal view

Trouble Grandeur V6 2.0L DOHC vehicle: Vehicle take off with 2 or 3 gear shifting. Acceleration is impossible and VS is displayed with 40 - 70 Km/H on scanner even if vehicle stop.

10.4 Vehicle Speed Sensor Field Service Example

VS signal is not related to shape. Only check how many detect signal above 1.0 volt per 1sec.

VS signal with problem detection

52


About EGR This is a valve to add exhaust gas into the cylinder and so the combustion temperature is reduced.Reduced combustion temperature results reducing of nitrous-oxide emission.Exhaust gas is supplied through this valve by under-pressure of surge tank.

11.1 Introduction of EGR valve and principle

EGR type

Algorithm

Mostly used one is mechanical type that the valve is opened by under-pressure of surge tank as soon as solenoid valve is opened. And the solenoid valve is opened by ON/OFF system or duty system. In case of EEGR(Electric EGR) type, the EGR valve is opened by electromagnetic power..

EGR valve is opened within the range(2 - 7%) that is not to give big influence on engine operation. Opening value is controlled not to have big engine vibration. Therefore, in case of ON/OFF type, ON signal is activated in the area (engine speed & intake air flow )where no engine problem is found. With the EGR gas, ignition angle should be retarded about 4 - 8 degree

If the EGR gas is provided into the cylinder, combustion temperature is reduced and it is effective on reducing of nitrous-oxide emission.

Electric EGR valve Mechanical EGR valve

11. EGR valve control signal analysis

53


11.2 The Methodology of EGR Valve Signal Measurement

Hi-Scan Mode : Please perform following procedure on the screen, - Scope meter Engine Actuator EGR valve Measuring




54


Malfunction of EGR valve

Cause of trouble 1. Wiring circuit failure (Power supply or Ground line open or shorted)

or EGR solenoid valve malfunction 2. EGR valve is stuck for a while or friction increase by over heating.

Engine state

1. Severe engine vibration is occurred(Open stuck) or lean fuel control(MAP sensor type). 2. lean fuel control(MAP sensor type), fuel adaptation is increased to positive direction. Knocking is often taken place.3 Severe engine vibration (Engine is hard to start or severe engine vibration after start)

Normal signal

Trouble1. Malfunction of valve operation 2. EGR valve closed stuck3. EGR valve opened stuck

11.3 EGR Valve Operation Trouble type and Analysis

EGR valve operation can be checked only if it is operated. So, it should be checked with working acceleration pedal.


1. Always constant

EGR valve stuck is not checked with signal,indirectly it can be checked with O2 sensor signal. “Refer to O2 sensor chapter”

55


Field example of EGR valve malfunction : EGR valve closed stuck

Cause of trouble

EGR gas is not supplied in combustion chamber due to EGR valve closing stuck. At this time, ECM reduce fuel injection as much as EGR duty. So, injection is not sufficient and fuel adaptation is increased. And also knocking is occurred because ECM apply EGR activated ignition.

Related vehicle

This is occurred at EGR valve equipped vehicles with MAP sensor. MAF(Mass Air Flow:Hot Film Type)is also happened if ECM separately control EGR activated ignition.

Signal view

TroubleGrandeur V6 3.0L DOHC vehicle : Knocking is often taken place and intermittently fuel control is rich because fuel adaptation is increased to positive direction.

11.4 EGR Valve Field Service Example

EGR valve stuck is not checked with signal,indirectly it can be checked with O2 sensor signal.

O2 sensor signal with problem detection

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About valve Fuel vapor gas from fuel tank is not emitted to the air but stored in the canister to follow the emission regulation. And then this fuel vapor gas is supplied to the engine via purge valve during engine running.

12.1 Introduction of purge valve control and principle

Part type

Algorithm

Mostly used one is solenoid valve type that uses under-pressure of surge tank while valve is open. This is also divided into ON/OFF and duty type..

Purge valve is opened in the limit area no to give big influence on engine operation. Opening amount is controlled no to have rpm drop by too much rich fuel caused by purge gas. Therefore, in case of ON/OFF type, ON signal is controlled to activate in the area ( engine speed, intake air flow )of no engine problem.

Purge solenoid valve

Canister

If purge gas is supplied into the cylinder, mixture is getting richer. But as it is compensated by oxygen sensor, total fuel amount is same

12. Purge valve control signal analysis

57


12.2 The Methodology of Purge Valve Signal Measurement

Hi-Scan Mode : Please perform following procedure on the screen, - Scope meter Engine Actuator Purge valve Measuring




Canister purge solenoid

Canister purge solenoid valve

58


Malfunction of Purge valve

Cause of trouble 1. Wiring circuit failure (Power supply or Ground line open or shorted)

or Purge solenoid valve malfunction 2. Purge valve is stuck for a while or friction increase by over heating.

Engine state 1. Severe engine vibration is occurred when hot start(Open stuck) or

over fuel enrichment control.2. The smell of fuel gas is detected from vehicle.3. Severe engine vibration is occurred when hot start(Open stuck) or over fuel enrichment control.

Normal signal

Trouble1. Malfunction of valve operation 2. Purge valve closed stuck3. Purge valve opened stuck

12.3 Purge Valve Operation Trouble type and Analysis

Purge valve operation can be only checked with driving. It should be always constant with vehicle stop.


1. Always constant

Purge valve stuck is not checked with signal,indirectly it can be checked with O2 sensor signal. “Refer to O2 sensor chapter”

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Field example of Purge valve malfunction : Purge valve opened stuck

Cause of trouble

Purge valve is stuck at closed position with hot condition. At this time, over fuel gas is supplied into engine when vehicle start and it lead to make hard vehicle start.Engine vibration is still remained until fuel gas is completely exhausted.

Related vehicle

This is frequently taken place with Siemens purge valve equipped vehicle. With BOSCH valve, it is sometimes occurred.

Signal view

TroubleAccent 1.5L SOHC vehicle : Engine is hard to start when hot summer season. And fuel control is so rich with engine vibration after start.

12.4 Purge Valve Field Service Example

Purge valve stuck is not checked with signal,indirectly it can be checked with O2 sensor signal when fuel control is too rich.

O2 sensor signal with problem occurrence

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About sensor

13.1 Introduction of oxygen sensor control and principle

Sensor type

Algorithm

There are oxygen sensor without heater too. Oxygen sensor without heater is used to reduce the cost.

In order to prevent sensor over-heating, heater control is stopped at high exhaust gas temperature area. In case of engine start, sensor might be cracked by heating due to water on the sensor. Therefore, heating is start after water is evaporated

Oxygen sensor heater is a heater to heat up the tip of oxygen sensor. Since oxygen sensor activate when the sensor temperature is over 370degC, heater is needed to prevent delay of signal at low exhaust gas temperature.

13. Oxygen sensor heater control signal analysis

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13.2 The Methodology of O2 Sensor Heater Signal Measurement

Hi-Scan Mode : Please perform following procedure on the screen, - Scope meter Engine Sensor O2 sensor Measuring



Data analysisAbout SensorNormal value

62


Malfunction of O2 sensor heater

Cause of trouble

1. O2 sensor heater damage 2. Wiring circuit failure (Power supply or Ground line open or shorted)

Engine state

1,2 O2 sensor signal switching is too slow (Too slow light off) Intermittently exhaust gas is black and poor acceleration is detected and engine stall is occurred when fast acceleration. Fuel economy is bad.

Normal signal

Trouble1. Malfunction of valve operation (Power supply line is no problem but O2 sensor is not heated) 2. O2 sensor is not activated (Always OFF)

13.3 O2 Sensor Heater Operation Trouble type and Analysis

O2 sensor heater should be always “ON” if after start time is elapsed 40 sec (In case of duty type, it is “ON” above 95%)


1. Always constant

If O2 sensor heater signal is “OFF” when idle, error is detected.

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Field example of O2 sensor heater malfunction : Crack of tip

Cause of trouble

O2 sensor heater should be operated after removing humidity around tip. But as soon as engine is started, O2 sensor is heated at the same time. It result in crack of O2 sensor tip.

Related vehicle

Vehicle which is manufactured before 1995 year(BOSCH O2 sensor:Frequently occurrence, Woojin O2 sensor:Sometimes occurrence)

Signal view

TroubleHMC vehicles for US market : O2 sensor malfunction is many taken place in early winter season

13.4 O2 Sensor Heater Field Service Example

O2 sensor signal is not switched (Always constant).

O2 sensor signal with problem occurrence

Date post:	21-Nov-2014
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Hi-Scan Pro Utilization (EMS Diagnosis Manual)

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