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Possible Causes

WARNING: This page is about a different car, the 2002 Lincoln Navigator and 2002 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

A left side air bag circuit short to ground could be caused by a short to ground in White/Light Blue wire (circuit No. 1257), short to ground in Brown/Light Blue wire (circuit No. 1258), short to ground in left side air bag module or RCM internal fault.

  1. 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 FAULT CODES  under DIAGNOSTICS. Perform on-demand self-test. See ON-DEMAND SELF-TEST  under DIAGNOSTICS. If DTC B1993 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B1993 was not retrieved, fault is intermittent. Go to step  7 .

  2. Check left side air bag module

    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 B1993 is retrieved, go to step  5 . If DTC B1993 is not retrieved, go to next step.

  3. Check left side air bag circuit for short to ground

    Turn ignition switch to OFF position. Disconnect left side air bag simulator from harness connector. Measure resistance of White/Light Blue wire between ground and harness side of left side air bag module floor harness connector. See WIRING DIAGRAMS  . If resistance is less than 1000 ohms, repair short to ground in White/Light Blue wire. Go to step  8 . If resistance is more than 1000 ohms, go to next step.

  4. Check left side air bag circuit for short to ground

    Measure resistance of Brown/Light Blue wire between ground and harness side of left side air bag module floor harness connector. If resistance is less than 1000 ohms, repair short to ground in Brown/Light Blue wire. Go to step  8 . If resistance is more than 5 ohms, replace left side air bag module. See SIDE AIR BAG MODULE  under REMOVAL & INSTALLATION. Go to step  8 .
    NOTE: Do not separate or remove shorting bars from RCM connector C2004.

  5. Check left side air bag circuit to seat harness

    Turn ignition switch to OFF position. Access RCM and disconnect harness connectors C2004 and C2005. See RESTRAINTS CONTROL MODULE (RCM)  under REMOVAL & INSTALLATION. Measure resistance between and harness side of RCM connector C2004, terminal No. 2 (White/Light Blue wire) and harness side of RCM connector C2005, terminal No. 21 (Black/Orange wire, circuit No. 649). See Figure . If resistance is less than 10 k/ohms, repair short to ground in White/Light Blue wire. See WIRING DIAGRAMS  . If resistance is more than 10 k/ohms, go to next step.

  6. Check left side air bag circuit to seat harness

    Disconnect left side air bag module simulator from harness connector. Inspect all crimps, terminals, wires and connectors in circuit No. 1257 (White/Light Blue wire) between left side air bag module floor harness connector and RCM connector C2004, terminal No. 2. Inspect all crimps, terminals, wires and connectors in circuit No. 1258 (Brown/Light Blue wire) between left side air bag module floor harness connector and RCM connector C2004, terminal No. 3. See WIRING DIAGRAMS  . Also, check for pinched wires and damaged connector terminals. If any damage is found, repair or replace as necessary. Go to step  8 . If no damage is found, replace RCM. Go to step  8 .

  7. Check for intermittent fault

    Refer to continuous DTCs recorded in step  1 . If DTC retrieved in step  1 was a intermittent fault, check for cause of intermittent short to ground in White/Light Blue and Brown/Light Blue wire. 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. If DTC retrieved in step  1 was not a intermittent fault, go to next step.

  8. 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. DO NOT clear any DTCs until all DTCs have been resolved. See DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION  table. 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.
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