GM Service Manual Online
For 1990-2009 cars only

Circuit Description

When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) compares the restraints ID that is stored in the SDM to the restraints ID that is stored in the body control module (BCM). The restraints ID that is being compared contains the last four digits of the SDM part number. Then, the SDM compares the VIN that is stored in the SDM to the VIN that is stored in the BCM and powertrain control module (PCM). For more detailed information concerning the Class 2 data lines, refer to Data Link Communications Circuit Description in Data Link Communications.

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

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 the SDM does not match the VIN information that is stored in the BCM.

Action Taken When the DTC Sets

    • The SDM commands the AIR BAG indicator ON via Class 2 serial data.
    • The SDM disables all deployment loops.

Conditions for Clearing the DTC

The restraints ID that is stored in the SDM matches the restraints ID that is stored in the BCM and the VIN information that is stored in the SDM matches the VIN information that is stored in the BCM.

Diagnostic Aids

DTC B1001 is an indication that the restraints IDs stored in both the BCM and SDM do not match or that the VINs stored in both the BCM and SDM do not match. If either the BCM and/or PCM were replaced, the replacement modules need to be reprogrammed for proper operation.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Tests to see if the BCM or SDM has been replaced

  2. Tests to see if the correct VIN is programmed in the PCM

  3. Tests to see if the correct VIN is programmed in the BCM

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2

Was the body control module (BCM) or sensing and diagnostic module (SDM) replaced?

Go to Step 6

Go to Step 3

3

  1. Install a scan tool.
  2. With a scan tool, verify that the powertrain control module (PCM) is programmed with the correct VIN by comparing the VIN that is stored in the PCM to the VIN plate of the vehicle.

Does the scan tool indicate that the PCM is programmed with the correct VIN?

Go to Step 5

Go to Step 4

4

Use a scan tool and/or the techline machine to program the correct VIN into the PCM. Refer to PCM Replacement/Reprogramming in Engine Controls.

Did you complete the action?

Go to Step 8

--

5

With a scan tool, verify that the BCM is programmed with the correct VIN by comparing the VIN that is stored in the BCM to the VIN that is stored in the PCM.

Does the scan tool indicate that the BCM is programmed with the correct VIN?

Go to Step 7

Go to Step 6

6

Follow the instructions on the scan tool to properly reprogram the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control Systems.

Did you complete the action?

Go to Step 8

--

7

  1. Turn OFF the ignition.
  2. Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 8

--

8

  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 2

System OK