Possible Causes
WARNING: This page is about a different car, the 2002 Lincoln Blackwood. However, it is still accessible from the selected car via links, so may be relevant.
Inoperative AIR BAG warning light could be caused by worn or damaged instrument cluster, open or short in wiring harness, faulty AIR BAG warning 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 6 . - 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 C2041A. See RESTRAINTS CONTROL MODULE (RCM) under REMOVAL & INSTALLATION. Measure resistance between ground and RCM connector C2041A (component side), pin No. 20. See Fig 1 . If resistance is less than 10 ohms, replace RCM. Go to step 7 . If resistance is more than 10 ohms, go to next step. - Check circuit for short to ground
Reconnect RCM harness connector C2041A. Access instrument cluster and disconnect harness connector C220A. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. See Fig 2 . Measure resistance between ground and instrument cluster harness connector C220A, terminal No. 13 (Black/Yellow wire). See Figure . If resistance is less than 100 ohms, repair short to ground in Black/Yellow wire. See WIRING DIAGRAMS . Go to step 7 . If resistance is more than 100 ohms, go to next step. - Check circuit for open
Disconnect RCM harness connector C2041A. Measure resistance between ground and instrument cluster harness connector C220A, terminal No. 13 (Black/Yellow wire). If resistance is more than 10 ohms, repair open in Black/Yellow wire. Go to step 7 . If resistance is less than 10 ohms, go to next step. - Check instrument cluster
Reconnect instrument cluster harness connector C220A. Turn ignition switch to RUN position. Connect a fused jumper between ground and instrument cluster harness connector C220A, terminal No. 13 (backprobe instrument cluster connector terminal). If AIR BAG warning light illuminates, replace RCM. If AIR BAG warning light does not illuminate, repair instrument cluster. - Check for intermittent fault
If DTC retrieved in step 1 was an intermittent fault, check for cause of intermittent fault in AIR BAG warning light. 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. 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.