GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Important: 

   • Battery must be in a charged state to avoid misdiagnosis.
   • The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requires checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving and idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact in General Electrical Diagnosis Procedures for specifics.

1

  1. Disconnect the PCM C2 connector.
  2. Turn the ignition switch to the RUN position.

Is the charge indicator ON?

--

Go to Step 2

Go to step 5

2

Use a DMM to check circuit 25 for a short to ground.

Is there a short to ground in circuit 25?

--

Go to Step 3

Go to Step 4

3

Repair the short to ground in circuit 25.

Has the repair been made and the system rechecked?

--

System OK

--

4

Replace the instrument cluster. Refer to Instrument Panel Cluster in Instrument Panel, Gauges and Console.

Has the repair been made and the system rechecked?

--

System OK

--

5

  1. Connect the PCM C2 connector.
  2. Disconnect the generator connector.
  3. Turn the gear selector to PARK.
  4. Start the engine.
  5. Run the engine over 1200 RPM.

Is the charge indicator ON?

--

Go to Step 6

Go to Step 9

6

Use a DMM to check circuit 225 for a short to ground.

Is there a short in circuit 225?

--

Go to Step 7

Go to Step 8

7

Repair the short in circuit 225.

Has the repair been made and the system rechecked?

--

System OK

--

8

Service the PCM. Refer to Powertrain Control Module Replacement/Programming for 3100 (VIN M) or Powertrain Control Module Replacement/Programming for 3800 (VIN K).

Has the repair been made and the system rechecked?

--

System OK

--

9

Replace the generator. Refer to Generator Replacement for 3100 (VIN M) or Generator Replacement for 3800 (VIN K).

Has the repair been made and the system rechecked?

--

System OK

--