Diagnostic Aids

Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:

CIRCUIT PIN IDENTIFICATION

Circuit	PCM Pin No.	Wire Color
MIL	18	Violet

NOTE: If MIL never comes on, start testing at step 2.

MIL Always On

Perform QUICK TEST . If any DTCs are present, service as necessary before continuing. Turn ignition off. Disconnect PCM harness connector. Inspect harness connector for damage. Measure resistance between MIL and GND circuits at PCM harness connector. See CIRCUIT PIN IDENTIFICATION table. If resistance is not greater than 10 k/ohms, repair short in circuit between PCM harness connector and MIL. If resistance is greater than 10 k/ohms, go to TEST DR .

MIL Never On

Turn ignition on, with engine off. Check voltage between ground and fuse No. 29 in instrument panel fuse panel. If voltage reading is greater than 10 volts, go to step 4. If voltage reading is not greater than 10 volts, go to next step.

Check Battery Voltage

Turn ignition on. Check voltage at input side of fuse. If voltage reading is greater than 10 volts, replace fuse. If fuse blows again, check for a shorted circuit. If voltage reading is not greater than 10 volts, repair power distribution. See POWER DISTRIBUTION article in WIRING DIAGRAMS.

Check MIL Bulb

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

Check Power To Instrument Cluster

Disconnect instrument cluster harness connector. Turn ignition on. Measure voltage between ground and Blue wire at instrument cluster harness connector. See WIRING DIAGRAMS article. See CIRCUIT PIN IDENTIFICATION table. If voltage reading is greater than 10 volts, go to next step. If voltage reading is not greater than 10 volts, repair open in circuit.