## MIL Circuit Troubleshooting

1. | Turn the ignition switch OFF.

2. | Turn the ignition switch ON (II), and watch the MIL. Does the MIL stay off? YES - Go to 17. NO - Go to 3.

3. | Turn the ignition switch OFF.

4. | Turn the ignition switch ON (II), and wait 20 seconds, and watch the MIL. Does the MIL stay on or flash? YES - Go to 5. NO - The MIL circuit is OK.n

5. | Turn the ignition switch OFF.

6. | Connect the HDS.

7. | Turn the ignition switch ON (II), and read the HDS. Does the HDS communicate with the ECM? YES - Go to 8. NO - Go to ‘‘DLC Circuit Troubleshooting''.

8. | Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If any Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.n NO - Go to 9.

9. | Check the MIL in the DATA LIST with the HDS. Does it ON indicated? YES - Go to 12. NO - Substitute a known-good gauge assembly, and recheck. When the MIL circuit is OK, replace the original gauge assembly.n

10. | Check the SCS in the DATA LIST with the HDS. Is it ON display? YES - Go to 12. NO - Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.n

11. | Turn the ignition switch OFF, and wait 10 seconds.

12. | Connect the ECM test harness and the test pin box to the wire harness only, not to the ECM.

13. | Disconnect the HDS.

14. | Check for continuity between test pin box terminal No. 113 and body ground. Is there continuity? YES - Repair short in the wire between the ECM connector No. 4 terminal No. 32 (test pin box terminal No. 113) and the service check connector.n NO - Go to 15.

15. | Disconnect the gauge assembly 30P connector.

16. | Check for continuity between test pin box terminal No. 91 and body ground. Is there continuity? YES - Repair short in the wire between the ECM connector No. 4 terminal No. 10 (test pin box terminal No. 91) and the gauge assembly.n NO - Substitute a known-good ECM and recheck. If the symptom/indication goes away, replace the original ECM.n

17. | Try to start the engine. Does the engine start? YES - Go to 18. NO - Go to 23.

18. | Turn the ignition switch OFF.

19. | Check the No. 3 (7.5 A) fuse in the under-dash fuse/relay box. Is the fuse OK? YES - Check for an open in the wire between the gauge assembly and the No. 3 (7.5 A) fuse, if the wire is OK, go to 20. NO - Repair short in the wire between the gauge assembly and the No. 3 (7.5 A) fuse.n

20. | Connect the ECM test harness and the test pin box to the wire harness only, not to the ECM.

21. | Connect the test pin box terminal No. 91 to body ground with a jumper wire.

22. | Turn the ignition switch ON (II). Does the MIL come on? YES - Substitute a known-good ECM and recheck. If the symptom/indication goes away, replace the original ECM.n NO - Repair open in the wire between the ECM connector No. 4 terminal No. 10 (test pin box terminal No. 91) and the gauge assembly.n

23. | Turn the ignition switch OFF.

24. | Check the No. 11 (15 A) fuse in the under-dash fuse/relay box. Is the fuse OK? YES - Go to 25. NO - Go to 33.

25. | Connect the ECM test harness and the test pin box to the wire harness only, not to the ECM.

26. | Disconnect the inertia switch 3P connector.

27. | Connect inertia switch 3P connector terminals No. 1 and No. 3 with a jumper wire.

28. | Turn the ignition switch ON (II).

29. | Measure voltage between test pin box terminal No. 108 and body ground. Is there battery voltage? YES - Replace the inertia switch.n NO - Go to 30.

30. | Turn the ignition switch OFF.

31. | Remove the jumper wire from inertia switch 3P connector.

32. | Check for continuity between test pin box terminal No. 108 and inertia switch 3P connector terminal No. 3. Is there continuity? YES - Repair open in the wire between the inertia switch and the No. 11 (15 A) fuse.n NO - Repair open in the wire between the ECM connector No. 4 terminal No. 27 (test pin box terminal No. 108) and the inertia switch.n

33. | Remove the fuse cover.

34. | Remove PGM-FI main relay 2 (A) from the under-dash fuse/relay box.

35. | Connect the ECM test harness and the test pin box to the wire harness only, not to the ECM.

36. | Check for continuity between test pin box terminal No. 108 and body ground. Is there continuity? YES - Repair short in the wire between the ECM connector No. 4 terminal No. 27 (test pin box terminal No. 108) and the No. 11 (15 A) fuse, PGM-FI main relay 2.n NO - Go to 37.

37. | Check for continuity between test pin box terminals No. 4, No. 5, No. 98, No. 120 and body ground individually. Is there continuity? YES - Check for an open in the wire between PGM-FI main relay 1 and ECM connector No. 4 terminal No. 11 (test pin box terminal No. 92), if wire is OK, then go to fuel pump circuit troubleshooting.n NO - Repair open in the wire between the ECM connector No. 1 terminal No. 4 (test pin box terminal No. 4), ECM connector No. 1 terminal No. 5 (test pin box terminal No. 5), ECM connector No. 4 terminal No. 17 (test pin box terminal No. 98), ECM connector No. 4 terminal No. 39 (test pin box terminal No. 120) and G102.n