A-1: Malfunction Indicator Light (Mil) Inoperative

When ignition is on, PCM energizes main relay. As PCM is supplied with ignition power, MIL turns on. After engine starts, MIL will turn off if no malfunction is detected. If a malfunction is detected, MIL will remain on until system is repaired.

1. Remove PCM cover, located below right side of instrument panel. Turn ignition on. Using DVOM, measure voltage (backprobe) between ground and PCM 28-pin connector "D" terminal No. 3 (Black/White wire). If 10-14 volts exists, go to step  3 . If 10-14 volts does not exist, go to next step.
2. Check for blown BATT fuse No. 1 (80-amp) or IG fuse No. 3 (60-amp) in underhood fuse/relay center, located on right fenderwell. If BATT and IG fuses are okay, check for blown IG METER fuse No. 21 (20-amp) in instrument panel fuse block. If fuses are okay, check for open or poor connection in Black/White wire between PCM and fuse block. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary.
3. Using jumper wire, ground PCM 35-pin connector "A" terminal No. 34 (Violet/Yellow wire). Turn ignition on. If MIL comes on, go to A-3: PCM POWER & GROUND CIRCUIT CHECK/ENGINE NO START  . If MIL does not come on, check for bad MIL bulb. If MIL bulb is okay, check for open in Black/White wire between fuse block and MIL or Violet/Yellow wire between PCM and MIL. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary.