GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the generator connector.
  2. Attach a fused jumper between the generator connector terminal B and ground.
  3. Turn the ignition switch to the RUN position.

Is the charge indicator on?

-

Go to Step 6

Go to Step 2

2

  1. Disconnect the PCM connector C2.
  2. Attach a fused jumper between the PCM connector C2 terminal 16 and ground.

Is the charge indicator on?

--

Go to Step 9

Go to Step 3

3

Use a DMM in order to test for a poor connection or an open in circuits 25 and circuit 39. Also check the charge indicator lamp.

Is there a poor connection or an open in circuit 25 or circuit 39 and is the charge indicator lamp OK?

--

Go to Step 4

Go to Step 5

4

Repair the poor connection or open in circuit 25 or circuit 39. Also replace the charge indicator lamp if required.

Is the repair complete?

--

System OK

--

5

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

Is the repair complete?

--

System OK

--

6

Test for a poor connection at the generator terminal L (B on connector).

Is there a poor connection at the generator terminal L?

--

Go to Step 7

Go to Step 8

7

Repair the poor connection at the generator terminal L.

Is the repair complete?

--

System OK

--

8

Replace the generator. Refer to Generator Replacement or Generator Replacement .

Is the repair complete?

--

System OK

--

9

Use a DMM in order to test for a poor connection or an open in circuit 225.

Is there a poor connection or on open in circuit 225?

--

Go to Step 10

Go to Step 11

10

Repair the poor connection or open in circuit 225.

Is the repair complete?

--

System OK

--

11

Service the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls - 3.1L or Powertrain Control Module Replacement/Programming in Engine Controls - 3.8L.

Is the repair complete?

--

System OK

--