GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Has the vehicle been inspected for Diagnostic Trouble Codes (DTC's)?

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Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls 3.1 or Powertrain On Board Diagnostic (OBD) System Check in Engine Controls 3.8

2

Inspect CKT 121 between the instrument cluster connector terminal D6 and the ignition control module (ICM) connector terminal E (VIN K) or connector C1 terminal C (VIN M) for the following conditions:

    • An open
    • Any signs of excessive resistance
    • Any electromagnetic interference
    • A short to ground
    • A short to the battery voltage

Does an open, a short, excessive resistance, or electromagnetic interference exist in CKT 121?`

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Go to Step 3

Go to Step 4

3

Repair CKT 121 between the instrument cluster connector terminal D6 and the ICM connector terminal E (VIN K) or connector C1 terminal C (VIN M) as needed.

Is the repair complete?

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System OK

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4

Replace the instrument cluster. Refer to Instrument Cluster Replacement .

Is the repair complete?

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System OK

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