GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you review the Audible Warnings Description and perform the necessary inspections?

--

Go to Step 2

Go to Diagnostic Starting Point

2

  1. Using the scan tool, enter BCM Data List INPUT 1 and monitor the SEAT BELT BUCKLED input.
  2. Unfasten the driver's seat belt.

Is NO displayed?

--

Go to Step 3

Go to Step 6

3

Inspect the connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Are the connections in need of repair?

--

Go to Step 4

Go to Step 5

4

Repair the connections at the BCM as necessary. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 12

--

5

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

Did you complete the replacement?

--

Go to Step 12

--

6

  1. Disconnect the seat belt buckle switch connector.
  2. Jumper terminal A to terminal B.

Is NO displayed for the SEAT BELT BUCKLED input on the scan tool?

--

Go to Step 7

Go to Step 8

7

Replace the seat belt switch. Refer to Front Seat Belt Buckle Replacement in Seat Belts.

Did you complete the replacement?

--

Go to Step 12

--

8

  1. Disconnect the BCM connector C1.
  2. Connect a test lamp between connector C1 terminal A2 and terminal B11.
  3. Connect the seat belt buckle switch connector.
  4. Unbuckle the driver's seat belt.

Does the test lamp illuminate?

--

Go to Step 3

Go to Step 9

9

  1. Disconnect the seat belt buckle switch connector.
  2. Connect a test lamp between connector C1 terminal A2 and the seat belt switch connector terminal B (harness side).

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 11

10

Locate and repair the open or high resistance in CKT 238 between the BCM connector C1 terminal B11 and seat belt switch connector terminal A. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 12

--

11

Locate and repair the open or high resistance in CKT 1350 between the seat belt switch connector terminal B and G400. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2