## 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 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 - GO to the indicated DTC Troubleshooting. 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. Does 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 data link connector (DLC).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 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. 16 (7.5A) 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. 16 (7.5A) fuse, if the wire is OK, go to 20. NO - Repair short in the wire between the gauge assembly and the No. 16 (7.5A) 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 - 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 NO - Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.n

23. | Turn the ignition switch OFF.

24. | Check the No. 11 (15A) fuse in the under-dash fuse/relay box. Is the fuse OK? YES - Repair open in the wire between the ECM connector No. 4 terminal No. 27 (test pin box terminal No. 108) and the No. 11 (15A) fuse.n NO - Go to 25.

25. | Remove the driver's side under cover.

26. | Remove the relay holder (A) from the under-dash fuse/relay box, and remove the PGM-FI main relay 2 (blue) (B) from the relay holder (A).

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

28. | 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 No. 11 (15A) fuse.n NO - Go to 29.

29. | 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 the 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