GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition OFF.
  2. Roll down the windows.
  3. Close all of the doors.
  4. Connect a scan tool.
  5. Turn the ignition to the ON position.
  6. Using the scan tool, inspect for any DTCs in the body control module (BCM).

Does the scan tool show any DTCs?

--

Go to Diagnostic System Check - Body Control System in Body Controls

Go to Step 2

2

Using the scan tool, read the key in ignition switch status.

Does the scan tool show yes?

--

Go to Step 8

Go to Step 3

3

  1. Connect a fused jumper wire (back probe) terminal B4 of C201B to ground.
  2. Using the scan tool, read the key in ignition switch status.

Does the scan tool show yes?

--

Go to Step 4

Go to Step 5

4

Locate and repair CKT  1850 (BLK) for a open between C201B and ground.

Is the repair complete?

--

System OK

--

5

  1. Connect a fused jumper wire (back probe) terminal B3 of C201B to ground.
  2. Using the scan tool, read the key in ignition switch status.

Does the scan tool show yes?

--

Go to Step 6

Go to Step 7

6

Replace the key in ignition switch. Refer to Ignition Lock Cylinder Replacement - On Vehicle in Steering Wheel and Column Tilt.

Is the repair complete?

--

System OK

--

7

  1. Locate and repair the open in CKT 80 (LT GRN) between C201B and the BCM.
  2. If no open is found, replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

--

System OK

--

8

  1. Open the driver door.
  2. Using the scan tool, read the driver door jamb switch status.

Does the scan tool show ACTIVE?

--

Go to Step 9

Go to Step 10

9

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

--

System OK

--

10

  1. Disconnect the LH mini wedge (door jamb switch).
  2. Connect a fused jumper wire from terminal A or C of C1 to terminal D.
  3. Using the scan tool, read the driver door jamb switch status.

Does the scan tool show active?

--

Go to Step 11

Go to Step 12

11

Replace the LH mini wedge (door jamb switch). Refer to Front Side Door Lock Actuator Replacement in Doors.

Is the repair complete?

--

System OK

--

12

  1. Connect a fused jumper wire from terminal A or C of C1 to ground.
  2. Using the scan tool, read the driver door jamb switch status.

Does the scan tool show active?

--

Go to Step 13

Go to Step 14

13

Locate and repair CKT 1850 (BLK) for an open between the switch and ground.

Is the repair complete?

--

System OK

--

14

  1. Locate and repair the open in CKT 126 (TAN) between the switch and the BCM.
  2. If no open is found, replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Is the repair complete?

--

System OK

--