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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 267 (Supplemental Inflatable Restraint System - Except F150) >> Diagnostic Tests >> Test D: Passenger-Side Air Bag Deactivation (Pad) Switch Fault (DTC B1871) >> Possible Causes

Possible Causes

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An PAD switch fault could be caused by damaged or inoperative PAD switch, damaged or inoperative RCM, or short to battery, short to ground or open in White/Light Blue wire (circuit No. 1112).

  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 B1871 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B1871 was not retrieved, fault is intermittent. Go to step  6.
  2. Check PAD switch ON position

    Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Access RCM and disconnect harness connector. See RESTRAINTS CONTROL MODULE (RCM)  under REMOVAL & INSTALLATION. Turn PAD switch to ON position. Measure resistance between harness side of RCM connector terminals No. 8 (White/Light Blue wire) and No. 21 (Black/Orange wire, circuit No. 649). See Figure. If resistance is 900-1100 ohms, go to next step. If resistance is not 900-1100 ohms, go to step  4.
  3. Check PAD switch OFF position

    Turn PAD switch to OFF position. Measure resistance between harness side of RCM connector terminals No. 8 (White/Light Blue wire) and No. 21 (Black/Orange wire). If resistance is 400-600 ohms, replace RCM. Go to step  7. If resistance is not 400-600 ohms, go to next step.
  4. Check circuit for short to battery

    Disconnect PAD switch harness connector. See PASSENGER-SIDE AIR BAG DEACTIVATION (PAD) SWITCH  under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. Measure voltage between ground and harness side of RCM connector terminal No. 8 (White/Light Blue wire). Measure voltage between ground and harness side of RCM connector terminal No. 21 (Black/Orange wire). If voltage is less than 0.2 volt on both circuits, go to next step. If voltage is more than 0.2 volt on either circuit, repair short to battery in appropriate wire. See WIRING DIAGRAMS . Go to step  7.
  5. Check circuit for open

    Turn ignition switch to OFF position. Measure resistance between harness side of RCM connector terminal No. 8 and harness side of PAD switch connector terminal No. 6 (White/Light Blue wire). See Figure & Fig 1 . If resistance is less than 5 ohms, replace PAD switch. Go to step  7. If resistance is more than 5 ohms, repair open in White/Light Blue wire. Go to step  7.
  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 B1871 was retrieved during on-demand self-test, fault is hard. Go to step  2. If DTC B1871 was not retrieved, fault is intermittent. Check for cause of intermittent faults in White/Yellow 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.
  7. 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 continuous 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.
Fig 1: Identifying Passenger-side Air Bag Deactivation (PAD) Switch Connector Terminals
G99H25467Courtesy of FORD MOTOR CO.