Test NB: Malfunction Indicator Light: Testing

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

1) MIL Always On: Check MIL Circuit For Short To Ground
Perform QUICK TEST . If any DTCs are present, service as necessary before continuing. Turn ignition off. Disconnect PCM harness connector. Inspect connector for damaged pins and repair if necessary. Using DVOM, measure resistance between MIL and GND circuits at PCM harness connector. See PCM TERMINAL CIRCUIT IDENTIFICATION table. If all resistances are more than 10 k/ohms, go to TEST DR , step 1). If any resistance is 10 k/ohms or less, repair short between circuits. See WIRING DIAGRAMS article.

NOTE: For additional testing information, see DIAGNOSTIC AIDS . If vehicle is a no-start, go to TEST A , step 1) before performing this test.

2) MIL Never On
Turn ignition on. Using DVOM, measure voltage between chassis ground and output side of fuse No. 37 (10-amp) in central junction box. If voltage is more than 10 volts, go to step 4). If voltage is 10 volts or less, go to next step.

3) Check For Battery Voltage To MIL Fuse

Turn ignition on. Using DVOM, measure voltage between chassis ground and input side of fuse No. 37. If voltage is more than 10 volts, replace fuse. If fuse blows again, check for a short to ground in MIL PWR circuit. If voltage is 10 volts or less, repair power circuit to MIL fuse. See POWER DISTRIBUTION article in WIRING DIAGRAMS.

4) Check MIL Bulb

Turn ignition off. Remove instrument cluster. Remove MIL bulb. Using DVOM, measure continuity across bulb contacts. If continuity exists, go to next step. If continuity does not exist, replace bulb and verify operation.

5) Check For Open Power Supply To Instrument Cluster

Disconnect instrument cluster harness connector C266b (analog) or C267c (electronic). Turn ignition on. Using DVOM, measure voltage between chassis ground and Blue wire at instrument cluster harness connector C266b terminal No. 13 (analog) or harness connector C267c terminal No. 20 (electronic). See Figure or Figure . If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open in MIL PWR circuit. See WIRING DIAGRAMS article.

6) Check MIL Circuit Continuity

Ensure ignition is off. Disconnect instrument cluster harness connector. Disconnect PCM harness connector. Inspect connector for damaged pins and repair if necessary. Using DVOM, measure resistance of MIL circuit between PCM harness connector and instrument cluster connector. If resistance is less than 5 ohms, replace PCM. Verify MIL operation. If resistance is 5 ohms or more, repair open in circuit. Verify MIL operation.