Possible Causes
AIR BAG warning light inoperative condition could be caused by damaged Black/Yellow wire (circuit 608), damaged or burned out bulb or an instrument cluster malfunction.
- Check for hard or intermittent DTC
Ensure ignition is off. Connect scan tool to DLC. See USING SCAN TOOL under DIAGNOSTICS. Turn ignition switch to RUN position. Retrieve and record any continuous DTCs. See RETRIEVING FAULT CODES under DIAGNOSTICS. Perform on-demand self-test. See ON-DEMAND SELF-TEST under DIAGNOSTICS. If DTC B1869 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B1869 was not retrieved, fault is intermittent. Go to step 5. - Check ECS
Turn ignition off. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Access ECS and disconnect harness connector. See ELECTRONIC CRASH SENSOR under REMOVAL & INSTALLATION. Measure resistance between chassis ground and ECS pin No. 7. See Fig 1. If resistance is more than 100 ohms, go to next step. If resistance is less than 100 ohms, replace ECS. Go to step 6. - Check circuit for short to ground
Ensure ignition is off. Access and disconnect 10-pin instrument cluster connector C250A. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Measure resistance between ECS harness connector terminals No. 7 (Black/Yellow wire) and No. 21 (Black/Orange wire). If resistance is less than 100 ohms, repair short to ground in Black/Yellow wire. Go to step 6. If resistance is more than 100 ohms, go to next step. - Check circuit for open
Measure resistance of Black/Yellow wire between ECS harness connector terminals No. 7 and instrument cluster connector C250A, terminal No. 6. See Figure & Fig 2 . If resistance is more than 10 ohms, repair open in Black/Yellow wire. Go to step 6. If resistance is less than 10 ohms, repair instrument cluster as necessary. Go to step 6. - Check for intermittent fault
Refer to continuous DTCs recorded in step 1. If DTC retrieved in step 1 was an intermittent fault, check for cause of intermittent short to ground or open on Black/Yellow wire. Attempt to recreate fault by flexing wire harness and cycling ignition switch frequently. Repair any intermittent problems found. Go to next step. If DTC retrieved in step 1 was not an intermittent fault, go to next step. - Check for additional DTCs
Refer to continuous DTCs recorded in step 1. If any continuous DTCs were retrieved, go to diagnostic trouble code identification table for direction to appropriate test. See DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION table. If no continuous DTCs were retrieved, reconnect air bag system. Activate air bag system. See ACTIVATING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Prove out system. Clear all DTCs. See CLEARING FAULT CODES under DIAGNOSTICS.