Immobilizer System Troubleshooting
Immobilizer System Troubleshooting
'08-09 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 - Intermittent failure, the vehicle is OK at this time. Check the SYSTEM CHECK and STATUS LOG information. Immobilizer System Check
NO - Go to step 28.
6. Check to see if the immobilizer indicator comes on and blinks.
Does the indicator blink?
YES - Go to step 28.
NO - Go to step 7.
7. Disconnect the 7P connector from the immobilizer control unit-receiver.
8. Check to see if the immobilizer indicator goes off.
Does the indicator go off?
YES - Go to step 43.
NO - Go to step 9.
9. Turn the ignition switch to LOCK (0).
10. Remove the gauge assembly, and disconnect its connectors. Service and Repair
11. Check for continuity between 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 assembly. Service and Repair
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 7P connector from the immobilizer control unit-receiver.
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. 25 (7.5 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.
16. Using a jumper wire, connect the immobilizer control unit-receiver 7P connector 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 assembly, and disconnect connector A (22P). Service and Repair
18. Check for continuity between immobilizer control unit-receiver 7P connector terminal No. 5 (IMOLMP) and gauge assembly connector A (22P) terminal No. 4.
Is there continuity?
YES - Faulty immobilizer indicator, replace the immobilizer indicator bulb or gauge assembly.
NO - Repair an open in the wire.
19. Turn the ignition switch to LOCK (0).
20. Disconnect the 7P connector from the immobilizer control unit-receiver.
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. 2 (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, 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 connector E (31P).
27. Check for continuity between immobilizer control unit-receiver 7P connector terminal No. 1 (LG3) and ECM connector E (31P) terminal No. 3 (LG3).
Is there continuity?
YES - Check for a poor or loose connection at G101. If OK, substitute a known-good immobilizer control unit-receiver and recheck.
NO - Repair an open in the wire.
28. Turn the ignition switch to LOCK (0).
29. Connect the HDS to the data link connector.
30. Turn the ignition switch to ON (II).
31. Go to SYSTEM CHECK in IMMOBILIZER INFO of the HDS, Immobilizer System Check and look for the following information on the display:
- Harness short from the ECM to the immobilizer control unit-receiver. (IMOCD (S-Net) line short)
- The communication was not good between the ECM 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 by influence of some noise.
- Immobilizer control unit-receiver failure
- ECM failure
- Imoes unit failure
Does the HDS display any of the preceding information?
YES - Go to step 32.
NO - Go to step 37.
32. Turn the ignition switch to LOCK (0).
33. Disconnect the 7P connector from the immobilizer control unit-receiver, and the 5P connector from the imoes unit.
34. Jump the SCS line with the HDS.
35. Disconnect ECM connector E (31P).
36. Check for continuity between immobilizer control unit-receiver 7P connector terminal No. 2 IMOCD (S-Net) and body ground.
Is there continuity?
YES - Repair a short to ground in the wire.
NO - Go to step 43.
37. Verify the Status Log display on the HDS.
- Blown fuse
- Harness open from the ECM and the immobilizer control unit-receiver.
- The communication was not good between the ECM and the immobilizer control unit-receiver by battery voltage low.
- The communication was not good between the immobilizer control unit-receiver and the ECM by influence of some noise.
- Immobilizer control unit-receiver failure
- ECM failure
- Imoes unit failure
Does the HDS display any of the preceding information?
YES - Check the Possible Failures shown on the Status Log display. Immobilizer System Status Log
NO - Go to step 38.
38. Turn the ignition switch to LOCK (0).
39. Disconnect the 7P connector from the immobilizer control unit-receiver.
40. Jump the SCS line with the HDS.
41. Disconnect ECM connector E (31P).
42. Check for continuity between immobilizer control unit-receiver 7P connector terminal No. 2 IMOCD (S-Net) and ECM connector E (31P) terminal No. 27 IMOCD (S-Net).
Is there continuity?
YES - Go to step 43.
NO - Repair an open in the wire.
43. Check for continuity between imoes unit 5P connector terminal No. 2 IMOCD (S-Net) and ECM connector E (31P) terminal No. 27 IMOCD (S-Net).
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 , and recheck.
NO - Repair an open in the wire.
