Antitheft and Alarm Systems: Testing and Inspection
Immobilizer SystemTroubleshooting
Follow this procedure if the vehicle does not start, or after rewriting the ECM with the HDS and the vehicle does not start.
Note these items before troubleshooting:
- Due to the action of the immobilizer system, the engine takes slightly more time to start than 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, repeat the starting procedure. If the engine still does not start, troubleshoot the system.
1. Using a scan tool, check for a Diagnostic Trouble Code (DTC).
Is DTC P1607 indicated?
YES - Replace the ECM.
NO - Go to step 2.
2. Turn the ignition switch ON (II) with the proper key.
3. Check to see if the immobilizer indicator light comes on.
Does the indicator light blink?
YES - Go to step 4.
NO - Check for these problems:
- an open in the PNK wire between the gauge assembly and ECM.
- a faulty immobilizer indicator light.
4. Disconnect the 5P connector from the immobilizer receiver unit.
5. Check for voltage between the No.1 terminal and body ground with the ignition switch turned ON (II).
Is there battery voltage?
YES - Go to step 6.
NO - Check for these problems:
- a blown No.2 (15 A) fuse in the under-dash fuse/relay box.
- a blown No.46 (15 A) fuse in the main under-hood fuse/relay box.
- an open in the YEL/BLK wire between the PGM-FI main relay and immobilizer receiver unit.
- a faulty PGM-FI main relay.
6. Check for continuity between the No.4 terminal and body ground.
Is there continuity?
YES - Go to step 7.
NO - Repair open in the BRN wire between the immobilizer receiver unit and G101.
7. Check for continuity between the No.2 terminal and the ECM.
Is there continuity?
YES - Go to step 8.
NO - Repair open in the RED/BLU wire between the immobilizer unit and ECM.
8. Check for continuity between the No.3 terminal and ECM.
Is there continuity?
YES - Replace the immobilizer receiver unit. If the engine still won't start, substitute a known-good ECM, and recheck.
NO - Repair open in the PNK/BLU wire between the immobilizer unit and ECM.