Immobilizer System Troubleshooting
Troubleshooting1. Turn the ignition switch 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 - If available, check the Status Log in the Immobilizer Info with the HDS. If the Status Log is not available, the immobilizer system is OK at this time.
NO - Go to step 24.
6. Check to see if the immobilizer indicator comes on and blinks.
Does the indicator blink?
YES - Go to step 24.
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 - Substitute a known-good immobilizer control unit-receiver and/or ECM.
NO - Go to step 9.
9. Turn the ignition switch OFF.
10. Remove the gauge assembly and disconnect gauge assembly connector B (22P).
11. Check for continuity between the immobilizer control unit-receiver 7P connector No. 5 (IMOARM) terminal and body ground.
Is there continuity?
YES - Repair a short in the wire.
NO - Faulty immobilizer indicator, replace the gauge assembly.
12. Try to start the engine.
Does the engine start?
YES - Go to step 13.
NO - Go to step 18.
13. Turn the ignition switch OFF.
14. Disconnect the 7P connector from the immobilizer control unit-receiver.
15. Check for voltage between the immobilizer control unit-receiver 7P connector No. 7 (+B) terminal and body ground.
Is there battery voltage?
YES - Go to step 16.
NO - Faulty No. 9 (10 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. Remove the gauge assembly, and disconnect gauge assembly connector B (22P).
17. Check for continuity between the immobilizer control unit-receiver 7P connector No. 5 (IMOARM) terminal and gauge assembly connector B (22P) connector No. 1 terminal.
Is there continuity?
YES - Faulty immobilizer indicator, replace the gauge assembly.
NO - Repair an open in the wire.
18. Turn the ignition switch ON (II).
19. Check for voltage between the immobilizer control unit-receiver 7P connector No. 6 (IG1) terminal and body ground.
Is there battery voltage?
YES - Go to step 20.
NO - Faulty No. 4 (10 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.
20. Turn the ignition switch OFF.
21. Disconnect the 7P connector from the immobilizer control unit-receiver.
22. Disconnect the ECM connector E (31P).
23. Check for continuity between the immobilizer control unit-receiver 7P connector No. 1 (LG3) terminal and ECM connector E (31P) No. 3 terminal.
Is there continuity?
YES - Substitute a known-good immobilizer control unit-receiver and/or ECM.
NO - Repair an open in the wire. If the wire is OK, repair G101.
24. Turn the ignition switch OFF.
25. Connect the HDS to the data link connector.
26. Turn the ignition switch ON (II).
27. Look at the System Check in the Immobilizer Info with the HDS.
Is the immobilizer system normal?
YES - Go back to step 1.
NO - Go to step 28.
28. Verify the System Check display on the HDS.
Does the HDS display the following information?
- Harness short from the ECM to the immobilizer unit. (S-net line short)
- The communication was not good between the ECM and the immobilizer unit by the battery voltage low.
- The communication was not good between the immobilizer unit and the ECM by influence of some noise.
- Immobilizer unit failure
- ECM failure
YES - Go to step 31.
NO - Go to step 35.
29. Turn the ignition switch OFF.
30. Disconnect the 7P connector from the immobilizer control unit-receiver.
31. Disconnect the ECM connector E (31P) from the ECM.
32. Check for continuity between the immobilizer control unit-receiver 7P connector No. 2 (IMOCD) terminal and body ground.
Is there continuity?
YES - Repair a short in the wire.
NO - Substitute a known-good immobilizer control unit-receiver and/or ECM.
33. Verify the System Check display on the HDS.
Does the HDS display the following information?
- Blown fuse
- Harness open from the ECM and the immobilizer unit.
- The communication was not good between the ECM and the immobilizer unit by battery voltage low.
- The communication was not good between the immobilizer unit and the ECM by influence of some noise.
- Immobilizer unit failure
- ECM failure
YES - Go to step 34.
NO - Check the Possible Failures shown or the System Check display Index.
34. Turn the ignition switch OFF.
35. Disconnect the 7P connector from the immobilizer control unit-receiver.
36. Disconnect the ECM connector E (31P) from the ECM.
37. Check for continuity between the immobilizer control unit-receiver 7P connector No. 2 (IMOCD) terminal and ECM connector E (31P) No. 27 terminal.
Is there continuity?
YES - Substitute a known-good the immobilizer control unit-receiver and/or ECM.
NO - Repair an open in the wire.