GM Service Manual Online
For 1990-2009 cars only

Circuit Description

When you first turn the ignition switch to the RUN position, the inflatable restraint sensing and diagnostic module (SDM) compares the restraints ID stored in the SDM to the restraints ID stored in the body control module (BCM). The restraints ID being compared contains the last four digits of the SDM part number. The SDM then compares the vehicle identification number (VIN) stored in the SDM to the vehicle identification number (VIN) stored in the powertrain control module (PCM) or the vehicle control module (VCM). For more detailed information concerning the Class 2 serial data lines, refer to Data Link Communications Circuit Description in Data Link Communications.

Conditions for Setting the DTC

    • Ignition 1 voltage is within the normal operating voltage range.
    • The restraints ID stored in the SDM does not match the restraints ID stored in the BCM, or the VIN information stored in the SDM does not match the VIN information stored in the PCM/VCM.

This test is only run once during power up initialization.

Action Taken When the DTC Sets

    • The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.
    • The SDM disables all AIR BAG deployments.

Conditions for Clearing the DTC

    • The restraints ID stored in the SDM matches the restraints ID stored in the BCM and the VIN information stored in the SDM matches the VIN information stored in the PCM/VCM.
    • You issue a scan tool CLEAR CODES command.
    • A history DTC will clear once 255 malfunction free ignition cycles have occurred.

When the SDM detects that no DTCs are present, the SDM commands the AIR BAG warning lamp OFF.

Diagnostic Aids

DTC B1001 is an indication that the restraints ID stored in both the BCM and SDM do not match or that the VIN's stored in both the PCM/VCM and SDM do not match. If either the BCM and/or VCM/PCM were replaced, the replacement modules need to be reprogrammed for proper operation. In addition, if the BCM or SDM were replaced, the vehicle theft deterrent (VTD) system will also need to be reprogrammed.

Test Description

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

  1. This step checks to see if the correct VIN is programmed in the powertrain control module (PCM) or the vehicle control module (VCM).

  2. This step explains the proper steps to perform after a PCM/VCM has been replaced in order for the PCM/VCM to operate properly.

  3. This step explains the proper steps to perform after a BCM has been replaced in order for the BCM to operate properly.

  4. This step explains how to properly program the vehicle theft deterrent (VTD) system.

Step

Action

Value(s)

Yes

No

1

Did you perform the SIR Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, verify that the PCM/VCM is programmed with the correct VIN by comparing the VIN that is stored in the PCM/VCM to the VIN plate of the vehicle.

Is the PCM/VCM programmed with the correct VIN?

--

Go to Step 4

Go to Step 3

3

With a scan tool and/or techline machine, program the correct VIN into the PCM/VCM. Refer to PCM/VCM programming in Engine Controls.

Did you complete the programming procedure?

--

Go to Step 9

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4

Was the BCM replaced?

--

Go to Step 5

Go to Step 6

5

Program the BCM in order for the BCM to learn the restraints ID from the SDM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control Systems.

Did you complete the programming procedures?

--

Go to Step 8

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6

Was the SDM replaced?

--

Go to Step 8

Go to Step 7

7

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

--

Go to Step 8

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8

Reprogram the vehicle theft deterrent (VTD) system. Refer to PASSLOCK Reprogramming Seed and Key in Theft Deterrent.

Use the scan tool to perform the VTD relearn. Do not use the 30 minute manual procedure.: Did you complete the reprogramming procedure?

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Go to Step 9

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9

  1. Verify that all components, connectors, and CPAs are properly mounted.
  2. Use the scan tool in order to clear the DTCs.
  3. Turn the ignition switch OFF for 10 seconds.

Are all SIR components properly mounted and connected?

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Go to Diagnostic System Check - SIR

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