GM Service Manual Online
For 1990-2009 cars only

Circuit Description

After entering RUN mode, the inflatable restraint sensing and diagnostic module (SDM) and Radio receive the VIN from the BCM, via the class 2 serial data circuit. The SDM also receives a message from the BCM containing its restraints ID. The restraints ID contains the last four digits of the SDM part number. The modules compare the information stored in their memory with the information received from the BCM.

Conditions for Running the DTC

Battery voltage is between 9-16 volts.

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 information that is stored in either the SDM or Radio does not match the VIN information 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 via a class 2 serial data message.
    • The SDM disables all deployment loops.
    • The radio does not function and displays as many characters of the word "CALIBRATE" as will fit on the display.

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 is an indication that the restraints ID stored in both the BCM and the SDM do not match or that the VIN stored in the BCM does not match the VIN stored either in the SDM or in the radio. If any of the modules mentioned above were previously replaced, the replaced module needs to be reprogrammed for proper operation.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check for the system exhibiting the symptom?

Go to Step 2

Go to Control Module References for the applicable Diagnostic System Check

2

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

Is the DTC B1001 retrieved as a current DTC?

Go to Step 3

Go to Step 7

3

Were any of the following modules replaced?

    • BCM
    • Radio
    • SDM

Go to Step 4

Go to Step 5

4

Follow the correct 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

--

5

  1. Follow the correct 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 clean 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

6

Important: Perform the reprogramming 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