GM 25744736
Front Impact Sensor

Vehicle accidents that cause damage to any part of the area require the SIR side air bag sensor replacement in that particular section. This includes areas that experience compression or bending due to moderate collisions with trees. You need to change the sensor at all times independently of air bag deployment status or sensor visual condition because hidden faults including mounting bracket bending or wire insulation cuts could trigger SIR/side air bag system malfunction. Therefore, do not attempt to assess the sensor for damage; simply replace it. A sensor replacement is necessary when it generates an indication through Diagnostic Trouble Code (DTC) tables.

Initial steps to replace the inflatable restraint front end sensor involve disabling the SIR system. Begin by removing the connector position assurance (CPA) which connects the wiring harness to the inflatable restraint front end sensor. Then disconnect the wiring harness from the front end sensor. Note that the front end sensor mounting fastener has left-handed threads; Start by disengaging the SIR system then loosen the left-hand threaded fastener on the upper tie bar before extracting the front end sensor from its position. Remove any dirt and impurities before placing the sensor on the mounting surface with its arrow facing forward. Tighten the fastener to 9 N.m (80 lb in) during installation of the mounting devices. Connect the harness wiring connector to the front end sensor before installing the CPA to the wiring harness connector on the front end sensor. Finally, enable the SIR system.

Remove the SIS mounting fasteners and take out the SIS from the center pillar.

Reinstall the center pillar trim, move the seat back to its original position, and enable the SIR system.