MIL Circuit Troubleshooting

1.Turn the ignition switch ON (II).

2.Do the gauge self-diagnostic procedure.

Does the MIL indicator flash?


YES - Go to 3.


NO - Substitute a known-good gauge assembly, and recheck. If the MIL circuit is OK, replace the original gauge assembly.n


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 20.


NO - Go to 5.


5.Turn the ignition switch OFF.

6.Turn the ignition switch ON (II), and watch the MIL.

Does the MIL stay on or flash?


YES - Go to 7.


NO - The MIL circuit is OK.n


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?


YES - Go to 10.


NO - Go to ‘‘DLC Circuit Troubleshooting''.


10.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's troubleshooting.


NO - Go to 11.


11.Check the MIL in the DATA LIST with the HDS.

Is ON indicated?


YES - Go to 12.


NO - Substitute a known-good gauge assembly, and recheck. If the MIL circuit is OK, replace the original gauge assembly.n

12.Check the SCS in the DATA LIST with the HDS.

Is a short indicated?


YES - Go to 13.


NO - Go to 16.


13.Turn the ignition switch OFF, and wait 30 seconds.

14.Disconnect ECM connector No. 2 (58P).

15.Check for continuity between ECM connector No. 2 terminal No. 20 and body ground.

 

Is there continuity?


YES - Repair short in the wire between the service check connector and ECM connector No. 2 terminal No. 20.n


NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.n

16.Turn the ignition switch OFF, and wait 30 seconds.

17.Disconnect ECM connector No. 2 (58P).

18.Disconnect the gauge assembly 22P connector.

19.Check for continuity between ECM connector No. 2 terminal No. 42 and body ground.

 

Is there continuity?


YES - Repair short in the wire between the gauge assembly and ECM connector No. 2 terminal No. 42. n


NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.n

20.Try to start the engine.

Does the engine start?


YES - Go to 21.


NO - Go to 27.


21.Turn the ignition switch OFF.

22.Connect ECM connector No. 2 terminal No. 42 to body ground with a jumper wire.

 

23.Turn the ignition switch ON (II).

Is the MIL on?


YES - Check for an open in the wire between the gauge assembly and ECM connector No. 2 terminal No. 42.n


NO - Go to 24.


24.Turn the ignition switch OFF.

25.Connect the HDS.

26.Turn the ignition switch ON (II), and read the HDS.

Does the HDS communicate with the ECM?


YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.n


NO - Go to ‘‘DLC Circuit Troubleshooting''.

27.Press the inertia switch button.

28.Try to start the engine.

Does the engine start?


YES - Troubleshooting is complete.n


NO - Go to 23.


29.Check PGM-FI main relay 1.

Is PGM-FI main relay 1 OK?


YES - Go to 30.


NO - Replace  PGM-FI main relay 1.n


30.Inspect the No. 26 +B IGP (20 A) fuse inthe under-hood fuse/relay box.

Is the fuse OK?


YES - Go to 37.


NO - Go to 31.


31.Disconnect PGM-FI main relay 1.

32.Check for continuity between body ground and PGM-FI main relay 1 4P connector terminals No. 2 and No. 4 individually.

 

Is there continuity?


YES - Repair short in the wire between PGM-FI main relay 1 and the No. 26 +B IGP (20 A) fuse. Also replace the No. 26 +B IGP (20 A) fuse.n


NO - Go to 33.

33.Turn the ignition switch OFF, and wait 30 seconds.

34.Disconnect ECM connector No. 2 (58P).

35.Disconnect the fuel rail pressure control valve 2P connector.

36.Check for continuity between PGM-FI main relay 1 4P connector terminal No. 1 and body ground.

 

Is there continuity?


YES - Repair short in the wire between PGM-FI main relay 1, fuel rail pressure control valve and ECM connector No. 2 terminal No. 1, No. 3 or No. 5. Also replace the No. 26 +B IGP (20 A) fuse.n


NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.n

37.Turn the ignition switch OFF.

38.Disconnect PGM-FI main relay 1.

39.Measure voltage between body ground and PGM-FI main relay 1 4P connector terminals No. 2 and No. 4 individually.

 

Is there battery voltage?


YES - Go to 40.


NO - Repair open in the wire between PGM-FI main relay 1 and the No. 26 +B IGP (20 A) fuse.n


40.Disconnect ECM connector No. 2 (58P).

41.Connect PGM-FI main relay 1 4P connector terminal No. 3 to body ground with a jumper wire.

 

42.Check for continuity between ECM connector No. 2 terminal No. 19 and body ground.

 

Is there continuity?


YES - Go to 46.


NO - Go to 43.


43.Disconnect the inertia switch 3P connector.

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

 

45.Check for continuity between ECM connector No. 2 terminal No. 19 and body ground.

 

Is there continuity?


YES - Replace the  inertia switch.n


NO - Repair open in the wire between PGM-FI main relay 1 and ECM connector No. 2 terminal No. 19.n


46.Measure voltage between ECM connector No. 2 terminal No. 35 and body ground.

 

Is there battery voltage?


YES - Go to 48.


NO - Go to 47.

47.Inspect the No. 4 ACG (10 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?


YES - Repair open in the wire between the No. 4 ACG (10 A) fuse and ECM connector No. 2 terminal No. 1. n


NO - Repair short in the wire between the No. 4 ACG (10 A) fuse and ECM connector No. 2 terminal No. 1.n


48.Check for continuity between PGM-FI main relay 1 4P connector terminal No. 1 and ECM connector No. 2 terminals No. 1, No. 3, and No. 5 individually.

 

Is there continuity?


YES - Go to 49.


NO - Repair open in the wire between PGM-FI main relay 1 and ECM connector No. 2 terminal No. 1, No. 3 or No. 5.n

49.Check for continuity between body ground and ECM connector No. 2 terminals No. 2, No. 4, and No. 6 individually.

 

Is there continuity?


YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.n


NO - Repair open in the wire between PGM-FI main relay 1 and ECM connector No. 2 terminal No. 2, No. 4 or No. 6.n