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.
A left side air bag circuit short to battery could be caused by a short to battery on Red/Green wire (circuit No. 30S-JA37), short to battery on Black/Green wire (circuit No. 31S-JA37), short to battery in left side air bag module or an RCM internal fault.
- Check for hard or intermittent DTCs
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. Clear continuous DTCs. See CLEARING FAULT CODES under DIAGNOSTICS. Perform on-demand self-test. See ON-DEMAND SELF-TEST under DIAGNOSTICS. If DTC B1992 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B1992 was not retrieved, fault is intermittent. Go to step 5 . - Check left side air bag
Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Turn ignition switch to RUN position. Perform on-demand self-test. If DTC B1992 is retrieved, go to next step. If DTC B1992 is not retrieved, replace left side air bag module. See SIDE AIR BAG MODULE under REMOVAL & INSTALLATION. Go to step 6 .NOTE: Do not remove or separate shorting bars from RCM harness connectors C310A or C310B. - Check left side air bag module circuit
Turn ignition switch to OFF position. Access RCM and disconnect RCM connector C310B. See RESTRAINTS CONTROL MODULE (RCM) under REMOVAL & INSTALLATION. Disconnect air bag module simulator from left side air bag connector. Turn ignition switch to RUN position. Measure voltage between ground and RCM harness connector C310B, terminals No. 2 (Red/Green wire) and No. 3 (Black/Green wire). See Figure . If voltage is more than 0.2 volt, repair short to battery in appropriate wire. See WIRING DIAGRAMS . If voltage is less than 0.2 volt, go to next step. - Check air bag module wiring
Inspect all crimps, terminals, wires and connectors in circuit No. 30S-JA37 (Red/Green wire) between side air bag module connector and RCM connector C310B, terminal No. 2, and circuit No. 31S-JA37 (Black/Green wire) between side air bag module connector and RCM connector C310B, terminal No. 3. Check for pinched wires and damaged connector pin terminals. If any damage is found, repair as necessary. Go to step 6 . If no damage is found, replace RCM. 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 B1992 was retrieved during on-demand self-test, check for causes of intermittent fault at or near left side air bag module connector. Repair any intermittent faults found and go to next step. If no intermittent faults are found, go to step 3 . If DTC B1992 was not retrieved during on-demand self-test, check for causes of intermittent short to battery on Red/Green or Black/Green wires. See WIRING DIAGRAMS . Attempt to recreate fault by 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.