PGM-FI System

MIL Circuit Troubleshooting (cont'd)

11-401  

  1. Inspect the No. 20 IG1 (40A) fuse in the under-hood fuse/relay box.

Is the fuse OK?

YES

- Repair open in the wire between the No. 20 IG (40A) fuse and the gauge assembly. If the wires are OK, test the ignition switch (see page 22-83).

NO

- Repair short in the wire between No. 20 IG (40A) fuse and the under-dash fuse/relay box. Also replace the No. 20 IG1 (40A) fuse.


  1. Try to start the engine.

Does the engine start?

YES

- Go to step 14.

NO

- Go to step 17.


  1. Turn the ignition switch OFF.
  2. Connect ECM/PCM connector terminal E31 and body ground with a jumper wire.

ECM/PCM CONNECTOR E (31P)

Wire side of female terminals

  1. Turn the ignition switch ON (II).

Is the MIL on?

YES

- Substitute a known-good ECM/PCM and recheck (see page 11-313). If symptom/indication goes away, replace the original ECM/PCM.

NO

- Check for an open in the wire between the ECM/PCM (E31) and the gauge assembly. Also check for a blown MIL bulb. If the wires and the bulb are OK, replace the gauge assembly.


  1. Turn the ignition switch OFF.
  1. Inspect the No. 6 ECU (ECM/PCM) (15A) fuse in the under-hood fuse/relay box.

Is the fuse OK?

YES

- Go to step 25.

NO

- Go to step 19.


  1. Remove the blown No. 6 ECU (ECM/PCM) (15A) fuse in the under-dash fuse/relay box.
  2. Remove the PGM-FI main relay 1 (A).

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

Wire side of female terminals

Is there continuity?

YES

- Repair short in the wire between the No. 6 ECU (ECM/PCM) (15A) fuse and the PGM-FI main relay 1. Also replace the No. 6 ECU (ECM/PCM) (15A) fuse.

NO

- Go to step 22.