GM Service Manual Online
For 1990-2009 cars only

Circuit Description

After entering the RUN power mode, the inflatable restraint sensing and diagnostic module (SDM) receives the VIN from BCM, via the class 2 serial data circuit. The SDM also receives a message from the body control module (BCM) containing its restraints ID. The restraints ID contains the last four digits of the SDM part number. The module compares the information stored in its memory with the information received from the BCM. If either the VIN or the restraints ID stored in the BCM do not match those stored in the SDM, the SDM sets DTC B1001.

Conditions for Running the DTC

    • Battery voltage is between 9-16 volts.
    • The ignition is ON.

Conditions for Setting the DTC

The restraints ID that is stored in the SDM does not match the restraints ID that is stored in the BCM, or the VIN that is stored in the SDM does not match the VIN that is stored in the BCM.

Action Taken When the DTC Sets

The following module specific actions may occur:

    • The SDM commands the AIR BAG indicator ON.
    • The SDM disables all deployment loops.

Conditions for Clearing the DTC

    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Diagnostic Aids

DTC B1001 sets if the restraints ID or the VIN stored in the BCM and SDM do not match. If either the BCM or the SDM were replaced, that module needs to be reprogrammed for proper operation.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check-SIR?

Go to Step 2

Go to Diagnostic System Check - SIR in SIR

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Retrieve DTCs.

Is DTC B1001 a current DTC?

Go to Step 3

Go to Step 7

3

Has the BCM or SDM been replaced?

Go to Step 5

Go to Step 4

4

  1. Follow the current procedure to reprogram the module that set the DTC. Refer to Control Module References for the applicable programming procedure.
  2. Use the scan tool in order to clear the DTCs.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 6

Go to Step 7

5

Follow the procedure to reprogram the module that was replaced. Refer to Control Module References for the applicable programming procedure.

Did you complete the action?

Go to Step 7

--

6

Important: Perform the programming or setup procedure for the module, if required.

Replace the module that set the DTC. Refer to Control Module References .

Did you complete the replacement?

Go to Step 7

--

7

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 5

System OK