Ignition "OFF"
Disconnect ECM connector(C23-4)
Ignition "ON" & Engine "OFF"
Using a suitable wire, jumper the ECM harness connector(20/C23-4) to chassis ground.
Is MIL bulb illuminated?
YES
Go to next step
NO
Remove instrument cluster and inspect MIL bulb. If it is burned out, replace bulb. If bulb is okay, locate source of open between bulb and 20/C23-4 or between bulb and Meter Fuse. Repair as necessary and go to "Verification of Vehicle Repair" procedure
Remove wire from ECM harness connector(20/C23-4)
Does MIL bulb go out?
YES
Thoroughly check for loose, bent, or corroded terminals in MIL circuit (including circuit board). Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
Check for source of short to GND between bulb and ECM(20/C23-4). Repair as necessary. and go to "Verification of Vehicle Repair" procedure
