Possible Causes
WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. 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, inoperative RCM, damaged wiring, terminals or connectors, worn or damaged shorting bar or camming beam, or loss of RCM battery feed.
- Check for hard or intermittent DTC
Turn ignition switch to OFF position. Connect scan tool to DLC. See USING SCAN TOOL under DIAGNOSTICS. 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 or on-demand DTCs were retrieved, go to diagnostic trouble code identification table for direction to appropriate test. See DIAGNOSTIC TROUBLE CODE 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 connected and fully seated. See Fig 1 . If RCM connector C310A is fully connected, go to next step. If RCM connector C310A is not fully connected, reconnect connector. Go to step 7 . - Check ignition circuit for open
Disconnect negative battery cable and wait at least one minute. Disconnect RCM connector C310A. Connect negative battery cable. Turn ignition switch to ON position. Measure voltage between ground and harness side of RCM connector C310A, terminal No. 12 (Green/Yellow wire, circuit No. 1003). If voltage is 9-16 volts, go to next step. If voltage is not 9-16 volts, repair open in Green/Yellow wire. See WIRING DIAGRAMS . Go to step 7 . - Check ground circuit for open
Turn ignition switch to OFF position. Measure resistance between sheet metal ground near RCM and harness side of RCM connector C310A, terminal No. 16 (Black/Orange wire, circuit No. 649). If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Black/Orange wire. Go to step 7 . - Check AIR BAG warning light operation
Ensure instrument cluster connector C220B is connected. Turn ignition switch to ON position. Connect fused jumper between ground and harness side of RCM connector C310A, terminal No. 19 (Black/Yellow wire). If AIR BAG warning light goes out, replace RCM. Go to next step. If AIR BAG warning light does not go out, repair or replace instrument cluster. Go to next step. - Check circuit for open
Access and disconnect instrument cluster connector C220B. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Measure resistance between harness side of RCM connector C310A, terminal No. 19 and harness side of instrument cluster connector C220B, terminal No. 3 (Black/Yellow wire, circuit No. 608). See Fig 1 & Fig 2 . If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Black/Yellow wire. - 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 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.