Air Bag System Diagnostic System Check

WARNING: This page is about a different car, the 2001 GMC Safari and 2001 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Deactivate air bag system before performing any service operation involving steering column components. See appropriate AIR BAG RESTRAINT SYSTEMS article. Do not apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.

CAUTION: If any water enters vehicle's interior up to level of carpet or higher and soaks carpet, Sensing And Diagnostic Module (SDM) and SDM harness connector may need to be replaced. SDM could be activated when powered, which could cause deployment of air bag(s) and result in personal injury. Before attempting these procedures, air bag system must be disabled. See appropriate AIR BAG RESTRAINT SYSTEMS article. Turn ignition switch to LOCK position, inspect SDM mounting area, including carpet. If any significant soaking or evidence of significant soaking is detected, perform following task. Remove all water. Repair water damage. Replace SDM harness connector. Replace SDM. Failure to follow these tasks could result in possible air bag deployment, personal injury, or otherwise unneeded air bag system repairs.

NOTE: Air bag system may also be called Supplemental Inflatable Restraint (SIR), Supplemental Restraint System (SRS) or Inflatable Restraint Sensing And Diagnostic Module (SDM) system.

NOTE: Presence of DTCs which begin with "U" indicate some other module on class 2 serial data circuit is not communicating.

These diagnostic procedures will aid in repairing Supplemental Inflation Restraint (SIR) system malfunctions. For best results, use diagnostic procedures and follow sequence listed below: See diagnostic procedure as directed by air bag system diagnostic system check. Diagnostic procedures aid in diagnosing any SIR system malfunction. Bypassing procedures may result in following: Extended Diagnostic Time. Incorrect Diagnosis. Incorrect Parts Replacement. Repeat air bag system diagnostic system check after performing any repair or diagnostic procedures. This will verify that correct repair was performed. This will also ensure that no other malfunctions exist.

Observe instrument cluster while turning ignition switch to RUN position. Air bag indicator should flash 7 times. If indicator flashes 7 times, go to next step. If indicator does not flash 7 times, repair air bag system by symptom. For information on air bag DIAGNOSIS & TESTING or DISPOSAL PROCEDURES see lemon-25(R) AIR BAG SERVICE & REPAIR MANUAL, DOMESTIC & IMPORTED MODELS.
Connect scan tool to Data Link Connector (DLC). DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, go to TEST E: SCAN TOOL DOES NOT POWER UP under SYSTEM TESTS.
Turn ignition switch to RUN position. Using scan tool, attempt to communicate with Sensing And Diagnostic Module (SDM). If scan tool communicates with SDM, go to next step. If scan tool does not communicate with SDM, go to TEST D: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS.
Using scan tool, select DISPLAY DTCS function and retrieve any SDM DTCs. If scan tool displays any current or history DTCs, go to next step. If scan tool does not display any DTCs, system is okay.
If scan tool does not display any DTCs which begin with a "U", go to next step. If scan tool displays any DTCs which begin with a "U", go to TEST D: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS.
If scan tool display DTC B1000, go to DTC B1000: BODY CONTROL MODULE INTERNAL MALFUNCTION under DIAGNOSTIC TESTS. If scan tool displays any other DTCs, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .