For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: The VOLT indicator or CHECK GAGES message with the engine outline telltale is inoperative.
1 | Turn the ignition to RUN and the engine OFF. Disconnect the generator connector. Using a fused jumper, jump RED (225) (harness side) to ground. Does the volt indicator lamp light? | -- | Go to Step 2 | Go to Step 3
2 | Check the connections at the generator. If OK, replace the generator. Are the repairs complete? | -- | Go to Starter and Charging System Check . | --
3 | Reconnect the generator connector. Disconnect the PCM connector C1 (Oldsmobile) or the PCM connector C2 (Buick). Using a fused jumper, connect PCM CONN C1 TERM 75 (Oldsmobile) or PCM CONN C2 TERM 35 (Buick) to ground. Does the volt indicator lamp light? | -- | Go to Step 4 | Go to Step 5
4 | Check the PCM connections. Check the connector C101 (terminal F1) for proper terminal contact. If OK, repair the open in CKT 225 (RED) between the PCM and the generator. Are the repairs complete? | -- | Go to Starter and Charging System Check . | --
5 | Refer to Instrument Cluster Diagnosis. Are the repairs complete? | -- | Go to Starter and Charging System Check . | --