PGM-FI System

MIL Circuit Troubleshooting (cont'd)

11-542  

  1. Disconnect each of the components or the connectors below, one at a time, and check for continuity between the PGM-FI main relay 1 4P connector terminal No. 1 and body ground.
  • PGM-FI main relay 2
  • ECM/PCM connector A (31P)
  • Each injector 2P connector
  • Idle air control (IAC) valve 3P connector
  • Top dead centre (TDC) sensor 2P connector
  • Crankshaft position (CKP) sensor 3P connector

Wire side of female terminals

Is there continuity?

YES

- Go to step 16.

NO

- Replace the item that made continuity to body ground go away when disconnected. If the item is the ECM/PCM, substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/PCM.

Also replace the No. 6 ECU (ECM/PCM) (15 A) fuse.


  1. Disconnect the connectors of all following items.
  • PGM-FI main relay 2
  • ECM/PCM connector A (31P)
  • Injectors
  • Idle air control (IAC) valve
  • Top dead centre (TDC) sensor
  • Crankshaft position (CKP) sensor

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

Wire side of female terminals

Is there continuity?

YES

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

NO

- Replace the PGM-FI main relay 1. Also replace the No 6 ECU (ECM/PCM) (15A) fuse.

  1. Inspect the No. 17 FUEL PUMP (15A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES

- Go to step 30.

NO

- Go to step 19.


  1. Remove the blown No. 17 FUEL PUMP (15A) fuse in the under-dash fuse/relay box.
  2. Disconnect ECM/PCM connector E (31P).