MIL Circuit Troubleshooting
MIL Circuit Troubleshooting1. Turn the ignition switch ON (II).
2. Do the gauge self-diagnostic procedure.
Does the MIL flash?
YES - Go to step 3.
NO - Substitute a known-good gauge assembly, and recheck. If the MIL circuit is OK, replace the original gauge assembly.
3. Turn the ignition switch OFF.
4. Turn the ignition switch ON (II), and watch the MIL.
Does the MIL stay off?
YES - Go to step 19.
NO - Go to step 5.
5. Turn the ignition switch OFF.
6. Turn the ignition switch ON (II), wait 20 seconds, and watch the MIL.
Does the MIL stay on or flash more than 5 times?
YES - Go to step 7.
NO - The MIL circuit is OK.
7. Turn the ignition switch OFF.
8. Connect the HDS.
9. Turn the ignition switch ON (II), and read the HDS.
Does the HDS communicate with the ECM/PCM?
YES - Go to step 10.
NO - Go to "DLC Circuit Troubleshooting".
10. Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
YES - Go to the indicated DTC's troubleshooting.
NO - Go to step 11.
11. Check the MIL in the DATA LIST with the HDS.
Is ON indicated?
YES - Go to step 12.
NO - Substitute a known-good gauge assembly, and recheck. If the MIL circuit is OK, replace the original gauge assembly.
12. Check the SCS in the DATA LIST with the HDS.
Is a short indicated?
YES - Go to step 13.
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
13. Turn the ignition switch OFF.
14. Jump the SCS line with the HDS.
15. Disconnect ECM/PCM connector E (31P) and the HDS.
16. Check for continuity between ECM/PCM connector terminal E29 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM/PCM (E29) and the DLC.
NO - Go to step 17.
17. Disconnect gauge assembly connector B (16P).
18. Check for continuity between ECM/PCM connector terminal E31 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM/PCM (E31) and the gauge assembly.
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
19. Try to start the engine. Does the engine start?
YES - Go to step 20.
NO - Go to step 26.
20. Turn the ignition switch OFF.
21. Connect ECM/PCM connector terminal E31 to body ground with a jumper wire.
22. Turn the ignition switch ON (II).
Is the MIL on?
YES - Go to step 23.
NO - Check for an open in the wire between the ECM/PCM (E31) and the gauge assembly.
23. Turn the ignition switch OFF.
24. Connect the HDS.
25. Turn the ignition switch ON (II), and read the HDS.
Does the HDS communicate with the ECM/PCM?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Go to "DLC Circuit Troubleshooting".
26. Turn the ignition switch OFF.
27. Inspect the No.20 IG (50 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES - Check for an open in the wire between the No.20 IG (50 A) fuse and the ignition switch. If the wire is OK, go to step 28.
NO - Repair short in the wire between No.20 IG (50 A) fuse and the under-hood fuse/relay box. Also replace the No.20 IG (50 A) fuse.
28. Inspect the No.6 ECU (ECM/PCM) (15 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES - Go to step 35.
NO - Go to step 29.
29. Remove the blown No.6 ECU (ECM/PCM) (15 A) fuse from the under-hood fuse/relay box.
30. Remove the glove box and PGM-FI main relay 1 (FI MAIN) (A).
31. Check for continuity between body ground and PGM-FI main relay 1 (FI MAIN) 4P connector terminals No.2 and No.4 individually.
Is there continuity?
YES - Repair short in the wire between the No.6 ECU (ECM/PCM) (15 A) fuse and PGM-FI main relay 1 (FI MAIN). Also replace the No.6 ECU (ECM/PCM) (15 A) fuse.
NO - Go to step 32.
32. Disconnect each of the components or connectors below, one at a time, and check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No.1 and body ground.
- PGM-FI main relay 2 (FUEL PUMP)
- ECM/PCM connector A (31P)
- Each injector 2P connector
- Idle air control (IAC) valve 3P connector
- Camshaft position (CMP) sensor B 3P connector
- Crankshaft position (CKP) sensor 3P connector
Is there continuity?
YES - Go to step 33.
NO - Replace the component that made the short to body ground go away when disconnected. If the item is the ECM/PCM, update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM. Also replace the No.6 ECU (ECM/PCM) (15 A) fuse.
33. Disconnect the connectors from these components:
- PGM-FI main relay 2 (FUEL PUMP)
- ECM/PCM connector A (31P)
- Injectors
- Idle air control (IAC) valve
- Camshaft position (CMP) sensor B
- Crankshaft position (CKP) sensor
34. Check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No.1 and body ground.
Is there continuity?
YES - Repair short in the wire between PGM-FI main relay 1 (FI MAIN) and each item. Also replace the No.6 ECU (ECM/PCM) (15 A) fuse.
NO-Replace PGM-FI main relay 1 (FI MAIN). Also replace the No.6 ECU (ECM/PCM) (15 A) fuse.
35. Inspect the No.17 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES - Go to step 48.
NO - Go to step 36.
36. Remove the blown No.17 FUEL PUMP (15 A) fuse from the under-dash fuse/relay box.
37. Jump the SCS line with the HDS.
38. Disconnect ECM/PCM connector E (31P).
39. Check for continuity between ECM/PCM connector terminal E9 and body ground.
Is there continuity?
YES - Go to step 40.
NO - Replace the No.17 FUEL PUMP (15 A) fuse, and update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
40. Remove the glove box, and remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-hood fuse/relay box.
41. Check for continuity between ECM/PCM connector terminal E9 and body ground.
Is there continuity?
YES - Repair short in the wire between the No.17 FUEL PUMP (15 A) fuse and the ECM/PCM (E9), or between the No.17 FUEL PUMP (15 A) fuse and PGM-FI main relay 2 (FUEL PUMP). Also replace the No.17 FUEL PUMP (15 A) fuse.
NO - Go to step 42.
42. Remove the center console, the cargo floor covering, and both door sill trims.
43. Fold back the floor covering until the access panel is accessible.
44. Disconnect the fuel pump 5P connector.
45. Check for continuity between fuel pump 5P connector terminal No.5 and body ground.
Is there continuity?
YES - Repair short in the wire between the fuel pump and PGM-FI main relay 2 (FUEL PUMP). Also replace the No.17 FUEL PUMP (15 A) fuse.
NO - Go to step 46.
46. Reinstall PGM-FI main relay 2 (FUEL PUMP) (A).
47. Check for continuity between fuel pump 5P connector terminal No.5 and body ground.
Is there continuity?
YES-Replace PGM-FI main relay 2 (FUEL PUMP). Also replace the No.17 FUEL PUMP (15 A) fuse.
NO - Check the fuel pump, and replace it if necessary. Also replace the No.17 FUEL PUMP (15 A) fuse.
48. Jump the SCS line with the HDS.
49. Disconnect ECM/PCM connector E (31P).
50. Turn the ignition switch ON (II).
51. Measure voltage between ECM/PCM connector terminal E9 and body ground.
Is there battery voltage?
YES - Go to step 52.
NO - Repair open in the wire between the No.17 FUEL PUMP (15 A) fuse and the ECM/PCM (E9).
52. Measure voltage between ECM/PCM connector terminal E7 and body ground.
Is there battery voltage?
YES - Go to step 57.
NO - Go to step 53.
53. Turn the ignition switch OFF.
54. Remove the glove box, then remove PGM-FI main relay 1 (FI MAIN) (A) from the under-hood fuse/relay box.
55. Measure voltage between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No.4 and body ground.
Is there battery voltage?
YES - Go to step 56.
NO - Repair open in the wire between the No.6 ECU (ECM/PCM) (15 A) fuse and PGM-FI main relay 1 (FI MAIN).
56. Check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No.3 and ECM/PCM connector terminal E7.
Is there continuity?
YES - Test PGM-FI main relay 1 (FI MAIN). If the relay is OK, update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and the ECM/PCM (E7).
57. Reconnect ECM/PCM connector E (31P).
58. Turn the ignition switch ON (II).
59. Measure voltage between body ground and ECM/PCM connector terminals A2 and A3 individually.
Is there battery voltage?
YES - Go to step 66.
NO - Go to step 60.
60. Turn the ignition switch OFF.
61. Remove PGM-FI main relay 1 (FI MAIN) (A).
62. Turn the ignition switch ON (II).
63. Measure voltage between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No.2 and body ground.
Is there battery voltage?
YES - Go to step 64.
NO - Repair open in the wire between the No.6 ECU (ECM/PCM) (15 A) fuse and PGM-FI main relay 1 (FI MAIN).
64. Turn the ignition switch OFF.
65. Check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No.1 and ECM/PCM connector terminals A2 and A3 individually.
Is there continuity?
YES - Replace PGM-FI main relay 1 (FI MAIN).
NO - Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and the ECM/PCM (A2, A3).
66. Measure voltage between body ground and ECM/PCM connector terminals A4, A5, A8, and A9 individually.
Is there more than 0.2 V?
YES - Repair open in the wire(s) that had more than 0.2 V between G101 and the ECM/PCM (A4, A5, A8, A9).
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.