Possible Causes
WARNING: This page is about a different car, the 2003 Ford Econoline. However, it is still accessible from the selected car via links, so may be relevant.
AIR BAG warning light malfunction may be caused by damaged wiring on circuit No. 608 (Black/Yellow wire), damaged or burned-out AIR BAG warning light bulb or instrument cluster malfunction.
- Check for additional warning lights
Turn ignition switch to RUN position. If other charging system warning light in instrument cluster is inoperative, diagnose instrument cluster malfunction. Repair instrument cluster as necessary. If charging system warning light is not inoperative, go to next step. - Check for hard or intermittent DTC
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (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 B1868 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B1868 was not retrieved, fault is intermittent. Go to step 8 . - Check AIR BAG warning light
Turn ignition switch to RUN position. If AIR BAG warning light is illuminated continuously, go to step 7 . If AIR BAG warning light is not illuminated continuously, go to next step. - Check AIR BAG warning light illumination
Turn ignition switch to OFF position. Access and disconnect ECS module harness connector. See ELECTRONIC CRASH SENSOR (ECS) MODULE under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. If AIR BAG warning light is illuminated continuously, replace ECS module. Go to step 8 . If AIR BAG warning light is not illuminated continuously, go to next step. - Check circuit No. 608 for open
Turn ignition switch to OFF position. Access and disconnect instrument cluster connector. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Measure resistance between ECS module connector terminal No. 7 and instrument cluster connector terminal No. 6 (Black/Yellow wire). See Figure & Fig 1 . If resistance is less than 10 ohms, go to next step. If resistance is more than 10 ohms, repair open in Black/Yellow wire. See WIRING DIAGRAMS . Go to step 8 . - Check circuit for voltage
Turn ignition switch to RUN position. Measure voltage between ground and instrument cluster connector terminal No. 7 (White/Yellow wire, circuit No. 1044). See Fig 1 . If voltage is more than 9 volts, check for causes of intermittent open or short conditions. Attempt to recreate hard fault by flexing wire harness and cycling ignition key. Repair any intermittent problems found. If no intermittent problems are found, replace ECS module. Go to step 8 . If voltage is less than 9 volts, check fuse No. 14 (5-amp) located in instrument panel fuse block. See Figure . If fuse No. 14 is okay, repair open in White/Yellow wire. If fuse is blown, replace fuse. Go to step 8 . - Check circuit for short to ground
Turn ignition switch to OFF position. Separate shorting bar between ECS module connector terminals No. 7 and 21. Measure resistance between ground and harness side of ECS module connector terminal No. 7 (Black/Yellow wire). If resistance is less than 1000 ohms, repair short to ground in Black/Yellow wire. Inspect shorting bar for damage or short circuit. Go to next step. If resistance is more than 1000 ohms, replace ECS module. 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. DO NOT clear any DTCs until all DTCs have been resolved. If no continuous DTCs were retrieved, reconnect air bag system. Activate air bag system. See ACTIVATING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear all DTCs. See CLEARING FAULT CODES under DIAGNOSTICS.