1. Turn the ignition switch to RUN.
2. Turn ON the park lamps.
3. Connect a scan tool to the data link connector.
4. Monitor the normal mode of communication between the IPC and the PRNDL.

Does DIMMING VOLTAGE change as the panel switch is moved?

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Go to Step 4

Go to Step 2

1. Turn ON the park lamps.
2. Disconnect the instrument cluster connector C1.
3. Turn the ignition switch to RUN.
4. Use a DMM in order to measure the voltage at C16 (Pontiac) and C1 (Oldsmobile and Buick).

Does the voltage measure more than specifications and vary with dimmer switch movement?

0.9 V

Go to Step 5

Go to Step 3

Repair an open or short to CKT 8 feed to the instrument cluster.

Did you find and repair a condition?

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System OK

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Replace the PRNDL control module. Refer to Shift Indicator Replacement.

Did you complete the repair?

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System OK

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Replace the instrument cluster. Refer to IP Cluster Replacement.

Did you complete the repair?

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System OK

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