GM Service Manual Online
For 1990-2009 cars only

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.

Removal Procedure

  1. Disable the SIR system. Refer to Disabling the SIR System .
  2. Remove the front passenger seat. Refer to Front Seat Replacement - Bucket in Seats.
  3. Remove the passenger front carpet retainer. Refer to Front Carpet Retainer Replacement and Rear Carpet Retainer Replacement in Interior Trim.
  4. Remove the RF seat belt anchor bolt.
  5. Fold back the carpet to access the inflatable restraint sensing and diagnostic module (SDM).

  6. Object Number: 241291  Size: MH
  7. Remove the connector position assurance (CPA) (2) from the inflatable restraint sensing and diagnostic module (SDM) harness connector (3).
  8. Disconnect the SDM harness connector (3) from the SDM (5).
  9. Remove the SDM mounting fasteners (1).
  10. Remove the SDM (5) from the vehicle.

Installation Procedure


    Object Number: 241291  Size: MH
  1. Install the SDM (5) to the vehicle.
  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).

  5. Install the SDM harness connector (3) to the SDM (5).
  6. Install the connector position assurance (CPA) (2) to the SDM harness connector.
  7. Position the carpet to cover the inflatable restraint sensing and diagnostic module (SDM).
  8. Install the RF seat belt anchor bolt.
  9. Install the passenger front carpet retainer. Refer to Front Carpet Retainer Replacement and Rear Carpet Retainer Replacement in Interior Trim.
  10. Install the front passenger seat. Refer to Front Seat Replacement - Bucket in Seats.
  11. Enable the SIR system. Refer to Enabling the SIR System .
  12. If you replaced the SDM, perform the following procedure in order to update the BCM with the new SDM part number:
  13.         Important: The AIR BAG indicator may remain ON after the SDM is replaced. After programming the SDM part number into the BCM, cycle the ignition switch OFF and ON. This turns OFF the AIR BAG indicator and clears the DTC.

    10.1. Install a scan tool.
    10.2. Select the Special Functions option from the SIR Menu and press enter.
    10.3. Select the Setup SDM Part Number in BCM option and press enter.
    10.4. Follow the procedure on the scan tool display.
    10.5. Cycle the ignition switch OFF and ON.