Possible Causes
WARNING: This page is about a different car, the 2004 Mercury Monterey and 2004 Ford Freestar. 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 6 . - Check RCM connector
Disconnect connector C310A. Inspect component side of RCM connector C310A for worn or damaged camming beams. See Fig 2 . Inspect harness side of RCM connector C310A for damaged or dislodged shorting bars. See Fig 3 . Also check for foreign material. If camming beams and shorting bars are in good condition, go to next step. If camming beams and shorting bars are not in good condition, repair as necessary. Go to step 6 . - Check circuit for short to ground
Access instrument cluster and disconnect harness connector C220A. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Reconnect RCM harness connector C310A. Measure resistance between ground and harness side of instrument cluster connector C220A, terminal No. 1 (Black/Yellow wire, circuit No. 608). See Fig 4 . If resistance is more than 10 k/ohms, repair or replace instrument cluster. If resistance is less than 10 k/ohms, go to next step. - Check RCM
Disconnect RCM harness connectors. Measure resistance between ground and component side of RCM connector C310A, terminal No. 15. If resistance is more than 10 k/ohms, repair Black/Yellow wire. See WIRING DIAGRAMS . Go to next step. If resistance is less than 10 k/ohms, replace RCM. 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 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.