Possible Causes
WARNING: This page is about a different car, the 2004 Ford Econoline. However, it is still accessible from the selected car via links, so may be relevant.
An AIR BAG warning light that is continuously illuminated may be caused by disconnected RCM, damaged battery or ignition circuit, loss of ground circuit to RCM, faulty wiring, terminals or connectors, faulty instrument cluster or faulty RCM.
- Check for hard or intermittent DTC
Turn ignition switch to OFF position. Connect scan tool to DLC. Turn ignition switch to ON 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 continuous DTCs were retrieved, go to next step. If on-demand DTCs were retrieved, go to diagnostic trouble code identification table for direction to appropriate test. See DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION table. If no DTCs were retrieved, go to next step. - Check RCM connection
Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Access RCM. See RESTRAINTS CONTROL MODULE (RCM) under REMOVAL & INSTALLATION. Ensure RCM connector C310A is fully connected and locking tab is engaged. See Fig 1 . If RCM connector C310A is fully connected and locking tab is engaged, go to next step. If RCM connector C310A is not fully connected or locking tab is not engaged, reconnect connector and engaged locking tab as necessary. Go to step 7 . - Check Red/White wire for open
Disconnect RCM connector C310A. Turn ignition switch to ON position. Measure voltage between ground and harness side of RCM connector C310A, terminal No. 12 (Red/White wire, circuit No. 937). If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in Red/White wire. See WIRING DIAGRAMS . Go to step 7 . - Check Black/Light Blue wire for open
Turn ignition switch to OFF position. Measure resistance between ground and harness side of RCM connector C310A, terminal No. 16 (Black/Light Blue wire, circuit No. 1203). If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Black/Light Blue wire. Go to step 7 . - Check Black/Yellow wire for short to ground
Access and disconnect instrument cluster connector C220A. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. See Fig 2 . Measure resistance between ground and harness side of instrument cluster connector C220A, terminal No. 3 (Black/Yellow wire, circuit No. 608). If resistance is more than 10 k/ohms, replace instrument cluster. Go to step 7 . If resistance is less than 10 k/ohms, go to next step. - Check RCM
Disconnect both RCM harness connectors. Measure resistance between ground and component side of RCM connector C310A, terminal No. 15. See Fig 3 . If resistance is more than 10 k/ohms, repair Black/Yellow wire as necessary. Go to step 7 . If resistance is less than 10 k/ohms, replace RCM. Go to step 7 . - 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.