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Home >> Mazda >> 2013 >> 5 Grand Touring >> Repair and Diagnosis >> External Pages >> Different car >> Section 85 (Air Bag System) >> Diagnostic Tests >> Test V: Left-Side Air Bag Circuit Resistance High (DTC B1994) >> Possible Causes

Possible Causes

WARNING: This page is about a different car, the 2003 Mazda Tribute. However, it is still accessible from the selected car via links, so may be relevant.

Left-side air bag circuit high resistance could be caused by damaged White/Light Blue wire, damaged Brown/Light Blue wire, damaged 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 B1994 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B1994 was not retrieved, fault is intermittent. Go to step  5 .
  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 B1994 is not retrieved, replace left-side air bag module. See SIDE AIR BAG MODULE  under REMOVAL & INSTALLATION. Go to step  6 . If DTC B1994 is retrieved, go to next step.
    NOTE: By disconnecting RCM connector C2041B, circuit No. 1257 (White/Blue wire) and No. 1258 (Brown/Light Blue wire) are shorted together with shorting bar. Do not remove shorting bar.
  3. Check left-side air bag harness for high resistance

    Turn ignition switch to OFF position. Access and disconnect RCM connector C2041B. See RESTRAINTS CONTROL MODULE (RCM)  under REMOVAL & INSTALLATION. Remove left-side air bag module simulator. Zero ohmmeter. Measure resistance between White/Light Blue and Brown/Light Blue wires on RCM side of left-side air bag module floor harness connector. If resistance is more than one ohm, repair open in appropriate wire and go to step  6 . See WIRING DIAGRAMS  . If resistance is less than one ohm, replace RCM. Go to next step.
  4. Check left-side air bag circuit to seat harness

    Disconnect left-side air bag module simulator. Inspect all crimps, terminals, wires and connectors in White/Light Blue wire between left-side air bag module floor harness connector and RCM connector C2041B, terminal No. 2. See Figure . Inspect all crimps, terminals, wires and connectors in Brown/Light Blue wire between left-side air bag module floor harness connector and RCM connector C2041B, terminal No. 3. Also, check for pinched wires and damaged connector terminals. If any damage is found, repair/replace as necessary and go to step  6 . If no damage is found, replace RCM. Go to step  6 .
  5. 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 high resistance on White/Light Blue wire (circuit No. 1257) and Brown/Light Blue wire (circuit No. 1258). 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.
  6. 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 IDENTIFICATION  table. If no DTCs were retrieved, reconnect air bag system. Activate air bag system. See ACTIVATING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Prove out system. See PROVE OUT SYSTEM  under DIAGNOSTICS. Clear all DTCs. See CLEARING FAULT CODES  under DIAGNOSTICS.