Honda Immobilizer

1949 Chrysler, first with starter switch in ignition key

Theft deterrent passively or actively interrupts a circuit in the ignition, fuel,

or start circuit.

The key must be recognized in order for the vehicle to start.

6 Immobilizer types

Basic immobilizer components: Key/transponder,

lock cylinder (transceiver/receiver), Immobilizer control unit, ECM/PCM

Transponder Key does not contain batteries

There are billions of ID codes.

Each system has a receiver unit which is an antenna attached to the ignition switch.

Receiver unit energizes the transponder (key) and the transponder transmits the key code to the

immobilizer control unit.

The ECM/PCM receives the unique serial code from the

immobilizer control unit

Immobilizer control unit sends a unique serial code to the

ECM/PCM

ECM/PCM confirms the ID code, it sends a ‘handshake’ back to the

immobilizer control unit

Serial codes are mutually recognized, the ECM/PCM enables

the fuel system

Type one system, disables start and fuel

Type 2 systems use a receiver connected to the immobilizer controlunit which is built into the ECM/PCM

Type 3 and 4 systems use an immobilizer control unit and a

receiver built into one unit

Type 5 and 6 systems use a combination immobilizer control

unit & receiver along with an additional security IMOES unit

(immobilizer entry system)

Type 6, engine start then code is checked, no match = engine dies

Signal from the keyless access control unit is sent out to the

ECM/PCM and IMOES

Master key with black grip: ignition, door, trunk, & glove box. Valet key with gray grip: Ignition & door locks

traditional key and the sidewinder key (2002 & later)

Matrix H Key Cutting MachineRequired for Sidewinder Key

Type 2 & 3 stamped with a "F" for fixed transponder codes.

Type 4 - 6 stamped with a "V" for rolling transponder codes

Type 1 system: 1997 - 2001 Prelude, 1996 - 2004 3.5RL, &

1997-2005 NSX.

Type 1: Red learning key puts immobilizer systeminto a re-programming mode to add & delete keys.The red learning key will not start the engine.

A lost red learning key requires replacing the immobilizer control unit.

Green immobilizer system indicator confirms operation. Controlled by immobilizer unit in Types 1 through 5 and by CAN in Type 6.

Vehicles normally come with three keysHDS needed to program additional keys

If one key is being added, you only need one programmed key from the customer (except Type 1, all programmed keys are needed.)

At times, all programmed keys are needed for any system

Type 1 - 3 , ‘ilco’ Key Code Duplicator and ‘ilco’ programmable key blanks marked with "T5" can be

used to make a duplicate key,

Type 1 accept a total of 5 keys, not including the red learning key. Type

2 - 6 accept a total of 6 keys.

If no programmed keys, or system failure, you can still start the engine

using a cut key blank and a VIN specific Immobilizer ‘Brake Code’

5 digit brake code is entered using the ign switch & the parking brake

Cranks no start

Verify system indicator is working

Try using the key only without key rings

or other keys attached

HDS troubleshooting with System Check and Status Log

Results of system check

Status Log

Diagnosis Using PID data

BAN indicates immobilizer fault

HDS need for replacing parts

Early Type 2 requires all keys for PCM programming

If lamp on with engine running it is a free start