Shift Light: Testing and Inspection

Upshift Indicator Lamp

The diagnosis found here addresses an inoperative lamp condition.

If the lamp comes on and stays on with the engine running, refer to Computers and Control Systems for diagnosis of the Powertrain Control Module.

If no Computers and Control Systems problem is found, the following procedure will help locate a short or open in the lamp circuit.

1. Disconnect the battery negative cable.
Unplug the PCM connector B (white).
Install a jumper wire between the up-shift lamp driver circuit cavity of the PCM connector B and a good ground.
Connect the battery negative cable.
Turn the ignition switch to the ON position. The lamp should light.
Remove the jumper wire and the lamp should go OFF.
If OK, refer to Computers and Control Systems to diagnose the PCM.
If not OK, go to Step 2.
2. Turn the ignition switch to the OFF position.
Disconnect the battery negative cable.
Remove the instrument cluster bezel and the cluster assembly. Service and Repair
Install a jumper wire between the up-shift lamp driver circuit cavity of the cluster tell-tale connector and a good ground.
Connect the battery negative cable.
Turn the ignition switch to the ON position. The lamp should light.
If OK, go to Step 3.
If not OK, replace the faulty bulb.
3. Turn the ignition switch to the OFF position.
Disconnect the battery negative cable.
Unplug the cluster tell-tale connector.
Check for continuity between the up-shift lamp driver circuit cavity of the tell-tale connector and a good ground. There should be no continuity.
If OK, go to Step 4.
If not OK, repair the short circuit as required.
4. Check continuity between the up-shift lamp driver circuit cavities of the tell-tale connector and the PCM connector B. There should be continuity.
If OK, test complete.
If not OK, repair the open circuit as required.