Immobilizer System: Troubleshooting

Before troubleshooting the immobilizer system, troubleshoot any ECM/PCM diagnostic trouble codes (DTCs) (see GENERAL TROUBLESHOOTING INFORMATION ), and make sure the ECM/PCM has no malfunction.

Note these items before troubleshooting:

• Due to the action of the immobilizer system, the engine takes slightly more time to start than on a vehicle without an immobilizer system.
• When the system is normal, and the proper key is inserted, the indicator light comes on for 2 seconds, then it will go off.
• If the indicator starts to blink after 2 seconds, or if the engine does not start, remove any other immobilizer keys or large key fobs on the key ring, then repeat the starting procedure.

  If the engine still does not start, continue with this procedure.

1. Turn the ignition switch ON (II) with programmed key.
2. Check to see if the immobilizer indicator light comes on.

   Does the indicator light blink ? 

   1. YES  - Disconnect the 7P connector from the immobilizer control unit-receiver, then go to step  9 .
   2. NO  - Check for these problems, then go to step 3.
   • Blown No. 9 (10A) fuse in the under-hood fuse/relay box.
   • An open in the BLU/ORN wire between the gauge assembly and the immobilizer control unit-receiver.
   • A faulty immobilizer indicator light.
   • An open in the WHT/RED wire between the gauge assembly and the under-hood fuse/relay box.
3. Remove the driver's dashboard lower cover (see DRIVER'S DASHBOARD LOWER COVER REMOVAL/INSTALLATION ).
4. Remove the steering column lower cover (see STEERING COLUMN REMOVAL AND INSTALLATION ).
5. Disconnect the 7P connector (A) from the immobilizer control unit-receiver (B).
   Fig 1: Disconnecting 7-Pin Connector From Immobilizer Control Unit-Receiver

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
6. Check for voltage between the immobilizer control unit-receiver 7P connector No. 7 terminal and body ground.

   Is there battery voltage? 

   1. YES  - Go to step 7.
   2. NO  - Check for these problems:
   • Blown No. 9 (10A) fuse in the under-hood fuse/ relay box.
   • An open in the WHT/RED wire.
7. Check for voltage between the immobilizer control unit-receiver 7P connector No. 6 terminal and body ground with the ignition switch ON (II).

   Is there battery voltage? 

   1. YES  - Go to step 8.
   2. NO  - Check for these problems:
   • Blown No. 6 (15A) fuse in the under-hood fuse/relay box.
   • Faulty PGM-FI main relay 1.
   • An open in the YEL/BLK wire.
8. Check for voltage between the immobilizer control unit-receiver 7P connector No. 6 terminal and No. 1 terminal.

   Is there battery voltage? 

   1. YES  - Go to step 9.
   2. NO  - Check for these problems:
   • Open on the BRN/YEL wire.
   • Faulty ECM/PCM.
9. Check for continuity between the immobilizer control unit-receiver 7P connector No. 2 terminal and ECM/PCM terminal E27.

   Is there continuity? 

   1. YES  - Go to step 10.
   2. NO  - Repair the open in the WHT wire.
10. Disconnect the negative cable from the battery.
11. Disconnect ECM/PCM connector E.
12. Check for continuity between the immobilizer control unit-receiver 7P connector terminal No.2 and body ground.

    Is there continuity? 

    1. YES  - Repair short to ground in the WHT wire.
    2. NO  - Go to step 13.
13. Reconnect the 7P connector to the immobilizer control unit-receiver, the negative cable to the battery, and reconnect ECM/PCM connector E.
14. Check for voltage between the immobilizer control unit-receiver 7P connector No. 4 terminal and body ground with the parking brake lever pulled, then released.

    Is there 1 V or less, then 5 V or more? 

    1. YES  - Replace the immobilizer control unit-receiver. After replacing the immobilizer control unit-receiver, rewrite the unit with a HDS.
    2. NO  - Check for these problems:
    • Faulty parking brake switch or a poor body ground of the parking brake switch.
    • Repair open in the GRN/ORN wire.