GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Body Control System Schematics

1

Perform a Diagnostic System Check on the Body Control System.

Did you perform the Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Body Control System

2

Enter A Diagnostic System Check - Body Control System. Refer to Diagnostic System Check - Body Control System .

Does the BCM flash the fasten seat belt indicator to indicate the BCM type number?

Go to Step 3

Go to Step 4

3

Enter A Diagnostic System Check - Body Control System. Refer to Diagnostic System Check - Body Control System .

Does the BCM sound the chime to indicate the BCM type number?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4

  1. Turn the ignition switch OFF.
  2. Disconnect the BCM harness connectors.
  3. Turn the ignition switch ON, with the engine OFF.
  4. Connect a test lamp between the battery positive voltage, the ignition positive voltage and the accessory voltage circuits to the BCM harness connectors and a good ground.

Does the test lamp illuminate at all circuits?

Go to Step 5

Go to Step 7

5

Connect a test lamp between the BCM program enable circuit and a good ground.

Does the test lamp stay OFF?

Go to Step 6

Go to Step 8

6

Connect a test lamp between the battery positive voltage circuits and the BCM ground circuit.

Does the test lamp illuminate?

Go to Step 10

Go to Step 9

7

Test the indicated circuits for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

8

Test the BCM program enable signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

9

Test the ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

10

Inspect the BCM harness connectors for poor terminal contact. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 11

11

Replace the BCM with the correct BCM type, according to the vehicle equipment content/options. Refer to Body Control Module Replacement .

Is the repair complete?

Go to Step 12

--

12

  1. Reconnect all connectors.
  2. Perform A Diagnostic System Check - Body Control Systems.

Are you able to perform A Diagnostic System Check - Body Control Systems?

Go to Diagnostic System Check - Body Control System

Go to Step 4