Component Circuits Diagnosis

Use the following Diagnosis to determine if malfunction is caused by instrument panel cluster, wiring or another component. If cluster is the malfunctioning component, then the cluster needs to be replaced.

Residue from Silicon Based Cleaners
Refer to the "Cleaning Instrument Cluster Lens/Mask" procedures to remove the residue.

Headlamp Switch
Refer to Lever Combination Switch (LCS) for testing. Headlamp Switch

Repair/replace as needed.

I/P Cluster
If the complaint is the functionality of a gage, use the "System Performance Test" for that gage to start the diagnosis.

Replace I/P cluster as needed. Program odometer with vehicle mileage.

Oil Pressure Switch
Check the resistance through the switch to ground.

Switch is normally closed at: 9.6-40 kPa (1.4 to 5.8 psi) measured on dropping pressure.

Low Brake Fluid Switch
Check the resistance through the switch to ground.

Switch resistance: OPEN when brake fluid full. Less than one ohm when brake fluid low.

Park Brake Switch
Check the resistance through the switch to ground.

Switch resistance: Open with parking brake Off Less than four ohms when parking brake On.

Speedometer and Tachometer
Refer to System Performance Tests, for procedures to diagnosis the speedometer or tachometer.

ABS Control Module
Refer to Diagnostic Information procedures in the Antilock Brake System.

Repair/replace as needed.

Daytime Running Lights (DRL) Logic
The DRL logic is used to control the hi beam telltale and brake telltale.

The DRL logic is incorporated into the speedometer gage and is not separately replaceable.

With the key in the RUN position the following readings should appear when taking measurements at the specified pins of the instrument panel cluster harness connectors (disconnected from the instrument panel cluster.)

BLACK CONNECTOR
Pin H Battery voltage (RUN and START position only)

Pin M Battery voltage (at all times)

Pin K Continuity to ground

Pin N 0 Volts (with headlamps On and headlamp switch in HI beam or flash-to-pass psition)
Battery voltage (any other time)

Pin Q Continuity to ground (with brake brake On)
Open (with park brake Off)

If any of the above checks fail, repair the open/short in the malfunctioning circuit or component.

If all the above checks are correct, rule out all other possible causes in the cause/complaint table. If all others are ruled out, the problem is most likely the I/P cluster.

Verify that the complaint has been fixed. Repair/replace as needed.

Generator
Refer to Generator for diagnosis. Alternator

Repair/replace as needed.