GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

    CAUTION: Be careful when you handle a sensing and diagnostic module (SDM). Do not strike or jolt the SDM. Before applying power to the SDM:

       • Remove any dirt, grease, etc. from the mounting surface
       • Position the SDM horizontally on the mounting surface
       • Point the arrow on the SDM toward the front of the vehicle
       • Tighten all of the SDM fasteners and SDM bracket fasteners to the specified torque value
    Failure to follow the correct procedure could cause air bag deployment, personal injury, or unnecessary SIR system repairs.

    Caution: If any water enters the vehicle's interior up to the level of the carpet or higher and soaks the carpet, the sensing and diagnostic module (SDM) and the SDM harness connector may need to be replaced. The SDM could be activated when powered, which could cause deployment of the air bag(s) and result in personal injury. Before attempting these procedures, the SIR system must be disabled. Refer to Disabling the SIR System.

    With the ignition OFF, inspect the SDM mounting area, including the carpet. If any significant soaking or evidence of significant soaking is detected, you must perform the following tasks:

    1. Remove all water.
    2. Repair the water damage.
    3. Replace the SDM harness connector.
    4. Replace the SDM.
    Failure to follow these tasks could result in possible air bag deployment, personal injury, or otherwise unneeded SIR system repairs.

  1. Disable the SIR system. Refer to Disabling the SIR System .
  2. Remove the passenger front seat. Refer to Seat Replacement or to Split Bench Seat Replacement in Seats.
  3. Remove the passenger front carpet retainer, then roll back the carpet. Refer to Carpet Retainer Replacement in Interior Trim.

  4. Object Number: 217474  Size: SH
  5. Remove the connector position assurance (CPA) from the wiring harness connector to the inflatable restraint sensing and diagnostic module (SDM).

  6. Object Number: 217475  Size: SH
  7. Disconnect the SDM wiring harness connector from the SDM.

  8. Object Number: 217478  Size: SH
  9. Remove the SDM mounting fasteners (1).
  10. Remove the SDM (2) from the floor pan (3).

Important: If the SDM mounting holes or fasteners are damaged to the extent that the module can no longer be properly mounted, use the following repair. Tighten the replacement fastener with a hand tool in order to prevent stripping the replacement fastener.

First Repair


    Object Number: 217478  Size: SH
  1. Remove and discard the stripped fastener.
  2. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  3. Install the SDM with new fastener GM P/N 10156138.
  4. Tighten
    Tighten fastener to 10 N·m (89 lb in).

Second Repair

  1. Remove the stripped fastener and discard it.
  2. Install the SDM using a larger fastener GM P/N 10267482 with a washer GM P/N 11500305.
  3. Tighten
    Tighten fastener to 5 N·m (44 lb in).

Installation Procedure


    Object Number: 217478  Size: SH
  1. Install the SDM (2) to the floor pan (3).
  2. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  3. Install the SDM mounting fasteners (1).
  4. Tighten
    Tighten fasteners to 10 N·m (89 lb in).


    Object Number: 217475  Size: SH
  5. Install the SDM wiring harness connector to the SDM.

  6. Object Number: 217474  Size: SH
  7. Install the CPA to the SDM wiring harness connector.
  8. Install the carpet and the carpet retainer. Refer to Carpet Retainer Replacement in Interior Trim.
  9. Install the passenger front seat. Refer to Seat Replacement or to Split Bench Seat Replacement in Seats.
  10. Important: The AIR BAG indicator may remain ON after the SDM has been replaced. DTC B1001 may set requiring the SDM part number to be set in multiple modules. If the indicator remains ON after enabling the SIR system, perform the diagnostic system check and follow the steps thoroughly to ensure that the SDM is set properly.

  11. Enable the SIR system. Refer to Enabling the SIR System .