GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Start the engine.
  2. Connect a DMM (set at DC scale) between the generator L terminal and ground.

Is the voltage above the specified value?

8.0 V

Go to Step 2

Go to Step 3

2

Connect a DMM to the generator BAT terminal.

Is the voltage above the specified value?

8.0 V

Go to Step 4

Go to Step 5

3

  1. Inspect for an open or a poor connection in CKT 225 between generator terminal L and PCM connector C2 terminal 35.
  2. Repair as needed.

Is the circuit repair complete?

--

Go to Charging System Check

--

4

  1. Run the engine at fast idle.
  2. Turn all of the accessories off.
  3. Connect a DMM (DC scale) across the battery terminals.

Is the voltage within the specified range?

13.3--15.5 V

Go to Step 6

Go to Step 7

5

  1. Inspect between the generator BAT terminal and the battery for an open in CKT1.
  2. Repair as needed.

Is the circuit repair complete?

--

Go to Charging System Check

--

6

  1. Test the generator. Refer to Generator Not Operating Properly .
  2. Load test the battery. Refer to Battery Load Test .
  3. Repair as needed.

Is the repair complete?

--

Go to Charging System Check

--

7

Replace the generator.

Is the replacement complete?

--

Go to Charging System Check

--