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)?

--

Go to Step 2

Refer to Engine Controls

2

Is the speedometer inoperative?

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Go to Step 3

Gages Inoperative - All

3

  1. Disconnect the powertrain control module (PCM) connector C1.
  2. Turn the ignition switch to the RUN position.

Does the charge warning indicator light?

--

Go to Step 4

Go to Step 5

4

  1. Inspect CKT 25 for a short to ground.
  2. If OK, replace the instrument cluster. Refer to Instrument Cluster Replacement .
  3. Inspect the system.

Is the symptom still present?

--

--

System OK

5

  1. Connect a fused 3 amp jumper between the PCM harness connector terminal 36 and ground.
  2. Turn the ignition switch to the RUN position.

Does the charge warning indicator light?

--

Refer to Engine Electrical

Go to Step 6

6

Inspect for a poor connection or an open in CKT 25.

Does a poor connection or an open exist in CKT 25?

--

Go to Step 7

Go to Step 8

7

  1. Repair the poor connection or the open in CKT 25.
  2. Inspect the system.

Is the symptom still present?

--

--

System OK

8

  1. Inspect the warning indicator bulb and the bulb connection.
  2. If OK, replace the instrument cluster. Refer to Instrument Cluster Replacement .
  3. Inspect the system.

Is the symptom still present?

--

--

System OK