System Description

The vehicle is equipped with a type IV immobilizer system that will disable the vehicle unless the proper ignition key is used. This system consists of a transponder located in the ignition key, an immobilizer control unit-receiver, an indicator, imoes unit ('08-10 models), and the PCM.

When the immobilizer key is inserted into the ignition switch and turned to the ON (II) position, the immobilizer control unit-receiver sends power to the transponder in the ignition key. The transponder then sends a coded signal back to the immobilizer control unit-receiver, which sends a coded signal to the imoes unit, which confirms the code and signals the PCM to supply power to the fuel pump circuit. A communication agreement with the HDS is required at the PCM or the imoes unit after repair or replacement. When replacing the immobilizer control unit-receiver, all keys are required to be registered into the new immobilizer control unit-receiver. Any keys that were not registered in the immobilizer control unit-receiver will not start the vehicle.

Fig 1: Immobilizer Control Unit-Receiver System Diagram

Courtesy of AMERICAN HONDA MOTOR CO., INC.

• If the proper key has been used, the immobilizer indicator will come on for about 2 seconds, then go off.
• If the wrong key has been used or the code was not received or recognized by the units, the indicator will come on for about 2 seconds, then it will blink until the ignition switch is turned to LOCK (0).
• When the ignition switch is turned to LOCK (0), the indicator blinks for about 5 seconds to signal that the unit has reset correctly, then the indicator goes off.

IMMOBILIZER INDICATOR BLINKING PATTERN: 

IGNITION SWITCH		Courtesy of AMERICAN HONDA MOTOR CO., INC.
PROPER KEY INSERTED	INDICATOR	Courtesy of AMERICAN HONDA MOTOR CO., INC.
WRONG KEY INSERTED	INDICATOR	Courtesy of AMERICAN HONDA MOTOR CO., INC.