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

Caution: This vehicle is equipped with a Supplemental Inflatable Restraint (SIR) System. Failure to follow the correct procedure could cause the following conditions:

   • Air bag deployment
   • Personal injury
   • Unnecessary SIR system repairs
In order to avoid the above conditions, observe the following guidelines:
   • Refer to SIR Component Views in order to determine if you are performing service on or near the SIR components or the SIR wiring.
   • If you are performing service on or near the SIR components or the SIR wiring, disable the SIR system. Refer to Disabling the SIR System.

  1. Disable the SIR system. Refer to Disabling the SIR System .
  2. Remove the driver seat. Refer to Front Seat Replacement - Bucket in Seats.
  3. Remove the front door stepwell mat. Refer to Front Side Door Step Mat Replacement in Interior Trim.
  4. Fold back the carpet to access the inflatable restraint sensing and diagnostic module (SDM).
  5. Remove the connector position assurance (CPA) (4) from the inflatable restraint sensing and diagnostic module (SDM) harness connector (3).

  6. Object Number: 388365  Size: SH
  7. Disconnect the SDM harness connector (3) from the SDM.
  8. Remove the SDM (2) mounting fasteners (1).
  9. Remove the SDM from the vehicle (2).

Installation Procedure


    Object Number: 388365  Size: SH
  1. Install the SDM (2) to the vehicle (5).
  2. Notice: Refer to Fastener Notice in the Preface section.

  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 (2).
  6. Install the CPA (4) to the SDM harness connector (3).
  7. Position the carpet to cover the inflatable restraint sensing and diagnostic module (SDM).
  8. Install the front door stepwell mat. Refer to Front Side Door Step Mat Replacement in Interior Trim.
  9. Install the driver seat. Refer to Front Seat Replacement - Bucket in Seats.
  10. Enable the SIR system. Refer to Enabling the SIR System .