Test NB: Malfunction Indicator Light: Testing

WARNING: This page does not describe the selected car, but rather 25 other vehicles, including the 2002 Lincoln Town Car, 2002 Lincoln Navigator, 2002 Lincoln LS, 2002 Lincoln Continental, and 2002 Lincoln Blackwood. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Diagnostic procedures beginning with step 1) are performed when directed here from an MIL concern under WARNING INDICATOR LIGHTS under SYMPTOMS in TROUBLE SHOOTING - NO CODES - EEC-V - GASOLINE & NGV article. For Blackwood, Continental, Escape, Expedition, Focus, F150 Pickup, LS, Mustang, Navigator, Thunderbird, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT for MIL diagnosis.

1) MIL Always On: Check MIL Circuit For Shorts To GND In Harness
If vehicle will not start, go to TEST A, step 1) . Service all KOEO or Continuous Memory DTCs before continuing. If no DTCs are present, turn ignition switch to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between PCM harness connector terminals No. 2 (MIL), and PWR GND and SIG RTN circuit terminals. See PCM PWR GND, SIG RTN & VREF TERMINAL IDENTIFICATION table. See Figure. If resistance is 10 k/ohms or less, repair MIL circuit between PCM and MIL for short to PWR GND or SIG RTN circuit. If resistance is 10 k/ohms or more, replace PCM.

NOTE: If vehicle will not start, go to TEST A, step 1) .

2) MIL Never On
Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and output side of MIL fuse. For MIL fuse location, refer to wiring diagram in appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. If voltage is 10.5 volts or less, go to next step. If voltage is more than 10.5 volts, go to step 4).

3) Check For B+ Voltage To MIL Fuse

Using a DVOM, measure voltage between negative battery terminal and B+ (input) side of MIL fuse. If voltage is 10.5 volts or less, repair open in B+ circuit to MIL fuse. See POWER DISTRIBUTION article in WIRING DIAGRAMS. If voltage is more than 10.5 volts, replace MIL fuse and recheck MIL operation.

4) Check Voltage On B+ Circuit

Turn ignition switch to OFF position. Disconnect instrument cluster connector. Refer to appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and B+ circuit at instrument cluster harness connector. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in instrument cluster fuse or B+ circuit to instrument cluster. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Recheck MIL operation.

5) Check For Open MIL Circuit Between PCM & Instrument Cluster

Turn ignition switch to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of MIL circuit between PCM harness connector terminal No. 2 and MIL circuit at instrument cluster harness connector. See Figure. If resistance is 5 ohms or more, repair open in MIL circuit. Recheck MIL operation. If resistance is less than 5 ohms, check MIL bulb and instrument cluster. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Repair as necessary. If no concerns are found, replace PCM. Recheck MIL operation.