GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 1998 🢒 S/T Isuzu - 2WD 🢒 Restraints 🢒 SIR 🢒 Supplemental Restraint Sensing and Diagnostic Module Replacement

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 SRS system must be disabled. Refer to Disabling the SRS 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 SRS system repairs.

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 SRS system repairs.

Removal Procedure
  1. Disable the SRS. Refer to Disabling the SRS .
  2. Remove the drivers seat, Refer to Front Seat Replacement in Seats.
  3. Remove driver seat belt from floor. Refer to Seat Belt Replacement in Seat Belts.
  4. Remove the carpet retaining sill trim molding -- LH, Refer to Sill Trim Plate Replacement in Interior Trim.
  5. Remove the floor console (if equipped), Refer to Floor Console Replacement in Interior Trim.
  6. Fold back the carpet to access the supplemental restraint Sensing and Diagnostic Module (SDM).
  7. Remove the Connector Position Assurance (CPA) from the SDM harness connector.
  8. Disconnect the SDM harness connector from the SDM.

    9. Object Number: 187111 Size: SH
  9. Remove the SDM mounting fasteners (1).
  10. Remove the SDM (2) from the vehicle. (3).

Installation Procedure

    Object Number: 187111 Size: SH
  1. Install the SDM (2) to the vehicle (3).
  2. Install the SDM mounting fasteners (1).

    3. Tighten
    Tighten fasteners to 12 N·m (106 lb in). Refer to

    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.

    in Cautions and Notices.

  3. Install the SDM harness connector to the SDM.
  4. Install the Connector Position Assurance (CPA) to the SDM harness connector.
  5. Position the carpet to cover the supplemental restraint Sensing and Diagnostic Module (SDM).
  6. Install the floor console (if equipped), Refer to Floor Console Replacement in Interior Trim.
  7. Install the carpet retaining sill trim molding -- LH, Refer to Sill Trim Plate Replacement in Interior Trim.
  8. Install driver seat belt to floor. Refer to Seat Belt Replacement in Seat Belts.
  9. Install the driver seat, Refer to Front Seat Replacement in Seats.
  10. Enable the SRS. Refer to Enabling the SRS .