Possible Causes
WARNING: This page is about a different car, the 2002 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
Inoperative AIR BAG warning light could be caused by instrument cluster circuit failure, open or short in wiring harness, faulty light bulb, or damaged or inoperative RCM.
- 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 DIAGNOSTIC TROUBLE CODES (DTCS) 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 RCM
Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Access RCM and disconnect harness connector C310A. See RESTRAINTS CONTROL MODULE (RCM) under REMOVAL & INSTALLATION. Measure resistance between ground and RCM connector C310A (component side), pin No. 20. See Fig 1 . If resistance is less than 100 ohms, replace RCM. Go to step 6 . If resistance is more than 100 ohms, go to next step. - Check circuit for short to ground
Measure resistance between RCM harness connector C310A, terminals No. 20 (Black/Green wire) and No. 21 (Black/Red wire, circuit No. 31S-JA10). See Figure . If resistance is less than 100 ohms, repair short to ground in Black/Green wire. See WIRING DIAGRAMS . Go to step 6 . If resistance is more than 100 ohms, go to next step. - Check circuit for open
Access instrument cluster and disconnect harness connector C220A. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. See Fig 2 . Measure resistance of Black/Green wire between RCM harness connector C310A, terminal No. 20 and instrument cluster connector terminal No. 22. See Figure & Fig 2 . If resistance is more than 10 ohms, repair open in Black/Green 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
Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Perform on-demand self-test. If DTC B1869 was retrieved during on-demand self-test, go to step 2 . If DTC B1869 was not retrieved during on-demand self-test, check for causes of intermittent short to ground or open in Black/Green wire. See WIRING DIAGRAMS . Attempt to recreate fault flexing wire harness and cycling ignition switch frequently. Repair any intermittent problems found. 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 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.