Immobilizer System

Symptom Troubleshooting Information

General Check before Troubleshooting

Before troubleshooting the immobilizer system, check the following general items:
- The battery is low; charge the battery fully, then troubleshoot the immobilizer system.
- The ignition key is not a genuine Acura part; use the Acura- approved key blank, register the key, then troubleshoot the immobilizer system.
- A key ring, or keys, or a key case is used; remove the key from it, and troubleshoot the immobilizer system with a key only.
- An aftermarket electrical part is attached; remove it, then troubleshoot the immobilizer system.

Symptom Troubleshooting Using the Immobilizer Indicator Lighting Pattern

NOTE: When symptom troubleshooting the immobilizer system, the built-in key must be in the ignition switch.

The pattern of the immobilizer indicator light can help troubleshooting the condition of the immobilizer system and the keyless access system. Following are descriptions of the five possible patterns:

Normal operation

When the ignition switch is turned ON (II) and the immobilizer code is identified, the immobilizer indicator comes on for 2 seconds, then goes off.
The immobilizer indicator blinks five times when the ignition switch is turned OFF.

+B line open

When the ignition switch is turned ON (II) and the immobilizer code is identified, the immobilizer indicator comes on for 2 seconds, then goes off.
The immobilizer indicator goes off when the ignition switch is turned OFF.

Immobilizer code is not identified

When the ignition switch is turned ON (II) but the immobilizer code is not identified, the immobilizer indicator comes on for 2 seconds, then blinks. The state of the immobilizer key registration and the IMOCD line can be checked by doing a SYSTEM CHECK with the HDS.
The immobilizer indicator goes off when the ignition switch is turned OFF.

Immobilizer indicator does not come on

If the immobilizer indicator does not come on when the ignition switch is turned ON (II), check for an open in the wire shown:

When the built-in key is used:
- Check for continuity between the immobilizer control unit-receiver and the keyless access control unit.
- Check for voltage to the immobilizer control unit-receiver IG1 and VBU +B line.
- Check for continuity between the immobilizer control unit-receiver and the gauge control module (IMOLMP line).

When the keyless access FOB is used:
- Check for voltage to the keyless access control unit IG1 and VBU +B, VBU +2, and Access lines.
- Check for continuity between the keyless access control unit and the gauge control module (IMOLMP line).
- Check for continuity between the keyless access control unit and body ground.

Immobilizer indicator does not go off

If the immobilizer indicator does not go off after the ignition switch is turned ON (II), check for a short to ground in the immobilizer circuit between the gauge control module and the immobilizer control unit-receiver.




Symptom Troubleshooting Using Malfunctioning Circuit Functions

If a malfunction occurs in the immobilizer circuit, use the following table to cross-reference the malfunctioning function to the line(s) that should be checked:

System Check and Status Log

NOTE: The HDS can be used to:
- Check the state of the immobilizer key registration and the IMOCD line by doing a SYSTEM CHECK.
- Check the number of times the immobilizer control unit-receiver doesn't permit the engine to run by checking the STATUS LOG.

1. Connect the HDS to the data link connector, then turn the ignition switch ON (II) and follow the prompts to the MAIN MENU.

NOTE: If the HDS does not communicate with the vehicle, go to the DLC circuit troubleshooting.

2. At the MAIN MENU, enter IMMOBILIZER, then select the IMMOBILIZER SET UP.
3. Do the SYSTEM CHECK. If there is a system check number, do the troubleshooting for the item indicated.
4. Check the status log using the HDS. Troubleshoot the line with the highest counts. If all the lines are "0" zero, the problem may not be caused by the immobilizer system, check for ignition or fuel problems.

NOTE: Once repaired, clear the status log by removing the No. 7 (10 A) fuse in the driver's under-dash fuse/relay box or disconnecting the battery.