Immobilizer System Troubleshooting
Immobilizer System Troubleshooting
Except '07 USA models
1. Turn the ignition switch to ON (II) with a programmed key.
2. Check to see if the immobilizer indicator comes on.
Does the indicator come on?
YES - Go to step 3.
NO - Go to step 12.
3. Check the immobilizer indicator operation.
Does the indicator come on for 2 seconds, then go off?
YES - Go to step 4.
NO - Go to step 6.
4. Try to crank the engine.
Does the starter motor operate?
YES - Go to step 5.
NO - Check the starter motor.
5. Try to start the engine.
Does the engine start?
YES - Check the Status Log in the Immobilizer Info with the HDS. Immobilizer System Status Log
NO - Go to step 32.
6. Check to see if the immobilizer indicator comes on and blinks.
Does the indicator blink?
YES - Go to step 29.
NO - Go to step 7.
7. Disconnect the immobilizer control unit-receiver 7P connector.
8. Check to see if the immobilizer indicator goes off.
Does the indicator go off?
YES - Substitute a known-good immobilizer control unit-receiver and/or ECM/PCM.
NO - Go to step 9.
9. Turn the ignition switch to LOCK (0).
10. Remove the gauge control module and disconnect its connector. Service and Repair
11. Check for continuity between the immobilizer control unit-receiver 7P connector terminal No. 5 (IMOLMP) and body ground.
Is there continuity?
YES - Repair a short to ground in the wire.
NO - Faulty immobilizer indicator, replace the gauge control module.
12. Try to start the engine.
Does the engine start?
YES - Go to step 13.
NO - Go to step 19.
13. Turn the ignition switch to LOCK (0).
14. Disconnect the immobilizer control unit-receiver 7P connector.
15. Measure the voltage between immobilizer control unit-receiver 7P connector terminal No. 7 (+B) and body ground.
Is there battery voltage?
YES - Go to step 16.
NO - Faulty No. 9 (10 A) fuse in the under-hood fuse/relay box. If the fuse is OK, check for an open in the wire between the immobilizer control unit-receiver and under-dash fuse/relay box.
16. Using a jumper wire, connect the immobilizer control unit-receiver terminal No. 5 (IMOLMP) to ground.
Does the indicator come on?
YES - Replace the immobilizer control unit-receiver.
NO - Go to step 17.
17. Remove the gauge control module and disconnect its 36P connector. Service and Repair
18. Check for continuity between immobilizer control unit-receiver 7P connector terminal No. 5 (IMOLMP) and gauge control module 36P connector terminal No. 7.
Is there continuity?
YES - Faulty immobilizer indicator, replace the immobilizer indicator bulb or gauge control module.
NO - Repair an open in the wire.
19. Turn the ignition switch to LOCK (0).
20. Disconnect the immobilizer control unit-receiver 7P connector.
21. Turn the ignition switch to ON (II).
22. Measure the voltage between immobilizer control unit-receiver 7P connector terminal No. 6 (IG1) and body ground.
Is there battery voltage?
YES - Go to step 23.
NO - Faulty No. 17 (15 A) fuse in the under-dash fuse/relay box. If the fuse is OK, check for an open in the wire between the immobilizer control unit-receiver and under-dash fuse/relay box.
23. Measure the voltage between immobilizer control unit-receiver 7P connector terminals No. 1 (LG3) and No. 6 (IG1).
Is there battery voltage?
YES - Substitute a known-good immobilizer control unit-receiver control, and recheck.
NO - Go to step 24.
24. Turn the ignition switch to LOCK (0).
25. Jump the SCS line with the HDS.
26. Disconnect ECM/PCM connector E (31P).
27. Check for continuity between immobilizer control unit-receiver 7P connector terminal No. 1 (LG3) and ECM/PCM connector E (31P) terminal No. 3.
Is there continuity?
YES - Go to step 28.
NO - Repair an open in the wire.
28. Check for continuity between imoes unit 5P connector terminal No. 1 (LG3) and ECM/PCM connector E (31P) terminal No. 3.
Is there continuity?
YES - Substitute a known-good immobilizer control unit-receiver and/or imoes unit, and recheck.
NO - Repair an open in the wire.
29. Turn the ignition switch to LOCK (0).
30. Connect the HDS to the data link connector.
31. Turn the ignition switch to ON (II).
32. Look at the System Check in the Immobilizer Info with the HDS. Immobilizer System Check
Is the immobilizer system normal?
YES - Go back to step 1.
NO - Go to step 33.
33. Verify the System Check display on the HDS.
- Harness short from the ECM/PCM to the immobilizer control unit-receiver. (IMOCD line short)
- The communication was not good between the ECM/PCM and the immobilizer control unit-receiver by the battery voltage low.
- The communication was not good between the immobilizer control unit-receiver and the ECM/PCM by influence of some noise.
- Immobilizer control unit-receiver failure
- ECM/PCM failure
Does the HDS display any of the preceding information?
YES - Go to step 34.
NO - Go to step 40.
34. Turn the ignition switch to LOCK (0).
35. Disconnect the immobilizer control unit-receiver 7P connector.
36. Jump the SCS line with the HDS.
37. Disconnect ECM/PCM connector E (31P).
38. Check for continuity between immobilizer control unit-receiver 7P connector terminal No. 2 (IMOCD) and body ground.
Is there continuity?
YES - Repair a short to ground in the wire.
NO - Go to step 39.
39. Check for continuity between imoes unit 5P connector terminal No. 2 (IMOCD) and body ground.
Is there continuity?
YES - Repair a short to ground in the wire.
NO - Substitute a known-good imoes unit, ECM/PCM and/or immobilizer control unit-receiver, and recheck.
40. Verify the System Check display on the HDS.
- Blown fuse
- Harness open from the ECM/PCM and the immobilizer control unit-receiver.
- The communication was not good between the ECM/PCM and the immobilizer control unit-receiver by battery voltage low.
- The communication was not good between the immobilizer control unit-receiver and the ECM/PCM by influence of some noise.
- Immobilizer control unit-receiver failure
- ECM/PCM failure
Does the HDS display any of the preceding information?
YES - Go to step 41.
NO - Check the Possible Failures shown on the System Check display. Immobilizer System Check
41. Turn the ignition switch to LOCK (0).
42. Disconnect the immobilizer control unit-receiver 7P connector.
43. Jump the SCS line with the HDS.
44. Disconnect ECM/PCM connector E (31P).
45. Check for continuity between immobilizer control unit-receiver 7P connector terminal No. 2 (IMOCD) and ECM/PCM connector E (31P) terminal No. 27 (IMOCD).
Is there continuity?
YES - Go to step 46.
NO - Repair an open in the wire.
46. Check for continuity between imoes unit 5P connector terminal No. 2 (IMOCD) and ECM/PCM connector E (31P) terminal No. 27 (IMOCD).
Is there continuity?
YES - Substitute a known-good imoes unit and/or immobilizer control unit-receiver, and recheck the system. If the imoes unit and/or immobilizer control unit-receiver is OK, substitute a known-good ECM/PCM, and recheck.
NO - Repair an open in the wire.
