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Home >> Ford >> 2000 >> Contour SE, 2.0 3, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 269 (Air Bag Restraint Systems) >> Diagnostic Tests >> Test G: Occupant Classification Sensor (OCS) Circuit Fault (DTC B2290) >> Possible Causes

Possible Causes

WARNING: This page is about a different car, the 2004 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

OCS circuit fault could be caused by damaged wiring, terminals or connectors, faulty OCS system or faulty RCM.

  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. Retrieve, flag and record any continuous Diagnostic Trouble Codes (DTCs). See RETRIEVING FAULT CODES  under DIAGNOSTICS. Flag DTC B2290. See BIT-MAPPED DIAGNOSTIC TROUBLE CODES  under DIAGNOSTICS. Retrieve and record any flagged DTCs. Perform on-demand self-test. See ON-DEMAND SELF-TEST  under DIAGNOSTICS. Retrieve and record any flagged DTCs. If flagged fault "?" was retrieved during on-demand self-test, multiple faults exist and all steps of diagnostic procedure must be performed. On models equipped with original part OCS, if DTC B2290 was retrieved during on-demand self-test, fault is hard.
    • For communication (COMM) fault, go to next step.
    • For internal (INT) fault, replace OCS system. See OCCUPANT CLASSIFICATION SENSOR (OCS)  under REMOVAL & INSTALLATION. Go to step  27 .
    • For calibration fault, replace OCS system. Go to step  27 .
    • For OCS pressure sensor fault, go to step  18 .
    • If DTC B2290 was not retrieved during on-demand self-test, fault is intermittent. Go to step  26 .

      On models equipped with service part OCS, if DTC B2290 was retrieved during on-demand self-test, fault is hard.

    • For communication (COMM) fault, go to next step.
    • For internal (INT) fault, replace OCS system. See OCCUPANT CLASSIFICATION SENSOR (OCS)  under REMOVAL & INSTALLATION. Go to step  27 .
    • For calibration fault, replace OCS system. Go to step  27 .
    • For OCS pressure sensor fault, replace OCS system. Go to step  27 .
    • If DTC B2290 was not retrieved during on-demand self-test, fault is intermittent. Go to step  26 .

  2. Check seat wiring & connectors

    Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Visually inspect all OCS system and seat wiring harnesses and connectors, RCM wiring and terminals at RCM harness connector C310B, terminals No. 17 and 18. If wiring harnesses and connectors are okay, go to next step. If wiring harnesses and connectors are damaged, repair as necessary. Go to step  27 .

  3. Check ignition circuit for open

    Access and disconnect OCS connector C3043 from OCS Electronic Control Unit (ECU). See OCCUPANT CLASSIFICATION SENSOR (OCS)  under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. Position front seat in vehicle and reconnect seat floor harness connectors. Turn ignition switch to RUN position. Measure voltage between ground and harness side of OCS connector C3043, terminal "G" (Green/Orange wire, circuit No. 15-JA10B). See Fig 1 . If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in Green/Orange wire. Go to step  27 . See WIRING DIAGRAMS  .

  4. Check ground circuit for open

    Turn ignition switch to OFF position. Measure resistance between ground and OCS connector C3043, terminal "D" (Black/Green wire, circuit No. 31-JA52). If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Black/Green wire. Go to step  27 .

  5. Check for short to battery between OCS electronic control unit & RCM

    Access and disconnect RCM connectors C310A and 310B. See RESTRAINTS CONTROL MODULE (RCM)  under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. Measure voltage between ground and harness side of OCS connector C3043, terminal "E" (Gray wire, circuit No. 4-EC9). Measure voltage between ground and harness side of OCS connector C3043, terminal "F" (Blue wire, circuit No. 5-EC9). If voltage is less than 0.2 volt in both circuits, go to next step. If voltage is more than 0.2 volt in either circuit, repair short to battery in appropriate wire. Go to step  27 .

  6. Check for short to ground between OCS electronic control unit & RCM

    Turn ignition switch to OFF position. Measure resistance between ground and harness side of OCS connector C3043, terminal "E" (Green/Yellow wire). Measure resistance between ground and harness side of OCS connector C3043, terminal "F" (Blue wire). If resistance is more than one megohm in both circuits, go to next step. If resistance is less than one megohm in either circuit, repair short to ground in appropriate wire. Go to step  27 .

  7. Check circuit for open between OCS electronic control unit & RCM

    Turn ignition switch to OFF position. Measure resistance between harness side of RCM connector C310B, terminal No. 18 and harness side of OCS connector C3043, terminal "F" (Blue wire). See Figure & Fig 1 . If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Blue wire. Go to step  27 .

  8. Check circuit for open between OCS electronic control unit & RCM

    Measure resistance between harness side of RCM connector C310B, terminal No. 17 and harness side of OCS connector C3043, terminal "E" (Gray wire). If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Gray wire. Go to step  27 .

  9. Check circuit for short between OCS electronic control unit & RCM

    Measure resistance between harness side of OCS connector C3043, terminals "E" (Gray wire) and "F" (Blue wire). If resistance is more than one megohm, go to next step. If resistance is less than one megohm, repair short between Gray and Blue wires. Go to step  27 .

  10. Check ignition circuit for open

    Disconnect right front seat harness connector C3047. Turn ignition switch to RUN position. Turn ignition switch to RUN position. Measure voltage between ground and harness side of right front seat connector C3047, terminal No. 1 (Green/Orange wire, circuit No. 15-JA10B). See Fig 2 . If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in Green/Orange wire. Go to step  27 . See WIRING DIAGRAMS  .

  11. Check ground circuit for open

    Turn ignition switch to OFF position. Measure resistance between ground and harness side of right front seat connector C3047, terminal No. 2 (Black/Green wire, circuit No. 31-JA52). If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Black/Green wire. Go to step  27 .

  12. Check for short to battery between OCS electronic control unit & RCM

    Access and disconnect RCM connectors C310A and 310B. See RESTRAINTS CONTROL MODULE (RCM)  under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. Measure voltage between ground and harness side of right front seat connector C3047, terminal No. 4 (Gray wire, circuit No. 4-EC9). Measure voltage between ground and harness side of right front seat connector C3047, terminal No. 3 (Blue wire, circuit No. 5-EC9). If voltage is less than 0.2 volt in both circuits, go to next step. If voltage is more than 0.2 volt in either circuit, repair short to battery in appropriate wire. Go to step  27 .

  13. Check for short to ground between OCS electronic control unit & RCM

    Turn ignition switch to OFF position. Measure resistance between ground and harness side of right front seat connector C3047, terminal No. 4 (Green/Yellow wire). Measure resistance between ground and harness side of right front seat connector C3047, terminal No. 3 (Blue wire). If resistance is more than one megohm in both circuits, go to next step. If resistance is less than one megohm in either circuit, repair short to ground in appropriate wire. Go to step  27 .

  14. Check circuit for open between OCS electronic control unit & RCM

    Turn ignition switch to OFF position. Measure resistance between harness side of RCM connector C310B, terminal No. 18 and harness side of right front seat connector C3047, terminal No. 3 (Blue wire). See Figure & Fig 2 . If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Blue wire. Go to step  27 .

  15. Check circuit for open between OCS electronic control unit & RCM

    Measure resistance between harness side of RCM connector C310B, terminal No. 17 and harness side of right front seat connector C3047, terminal No. 4 (Gray wire). If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Gray wire. Go to step  27 .

  16. Check circuit for short between OCS electronic control unit & RCM

    Measure resistance between harness side of right front seat connector C3047, terminals No. 4 (Gray wire) and No. 3 (Blue wire). If resistance is more than one megohm, go to next step. If resistance is less than one megohm, repair short between Gray and Blue wires. Go to step  27 .
    NOTE: Ensure all air bag system simulators, sensor electrical connectors and RCM electrical connectors are connected prior to carrying out on-demand self-test or erroneous faults may be set.

  17. Check OCS

    Install NEW OCS system service kit. Reconnect RCM connectors. Zero OCS. See ZERO OCCUPANT CLASSIFICATION SENSOR (OCS)  under DIAGNOSTICS. Turn ignition switch to ON position. Perform on-demand self-test. Flag DTC B2290. Retrieve and record any flagged faults. If flagged fault "?" was retrieved during on-demand self-test, multiple faults exist and all steps of diagnostic procedure must be performed. If DTC B2290 was retrieved during on-demand self-test, replace RCM. Go to step  27 . If DTC B2290 was retrieved during on-demand self-test, fault is corrected. Go to step  27 .

  18. Check seat wiring & connectors

    Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Visually inspect all OCS system and seat wiring harnesses and connectors. If wiring harnesses and connectors are okay, go to next step. If wiring harnesses and connectors are damaged, repair as necessary. Go to step  27 .

  19. Check circuits for short to battery

    Access and disconnect both RCM connectors. See RESTRAINTS CONTROL MODULE (RCM)  under REMOVAL & INSTALLATION. Access and disconnect OCS connector C3042 from OCS pressure sensor. See OCCUPANT CLASSIFICATION SENSOR (OCS)  under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. Measure voltage between ground and harness side of OCS pressure sensor connector C3042, terminals "A" (Brown/Green wire, circuit No. 9-JA52), "B" (White/Green wire, circuit No. 8-JA52) and "C" (Yellow/Green wire, circuit No. 7-JA52). See Fig 3 . If voltage is more than 0.2 volt in any circuit, repair short to battery in appropriate wire. See WIRING DIAGRAMS  . Go to step  27 . If voltage is less than 0.2 volt in all circuits, go to next step.

  20. Check circuits for short to ground

    Turn ignition switch to OFF position. Measure resistance between ground and harness side of OCS pressure sensor connector C3042, terminals "A" (Brown/Green wire), "B" (White/Green wire) and "C" (Yellow/Green wire). If resistance is more than one megohm, go to next step. If resistance is less than one megohm, repair short to ground in appropriate circuit. Go to step  27 .

  21. Check circuit for open between OCS pressure sensor & OCS Electronic Control Unit (ECU)

    Disconnect OCS ECU harness connector C3043. Measure resistance between harness side of OCS ECU connector C3043, terminal "J" and harness side of OCS pressure sensor connector C3042, terminal "C" (Yellow/Green wire). See Fig 1 & Fig 3 . If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Yellow/Green. Go to step  27 .

  22. Check circuit for open between OCS pressure sensor & OCS Electronic Control Unit (ECU)

    Measure resistance between harness side of OCS ECU connector C3043, terminal "H" and harness side of OCS pressure sensor connector C3042, terminal "A" (Brown/Green wire). If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Brown/Green wire. Go to step  27 .

  23. Check circuit for open between OCS pressure sensor & OCS Electronic Control Unit (ECU)

    Measure resistance between harness side of OCS ECU connector C3043, terminal "K" and harness side of OCS pressure sensor connector C3042, terminal "B" (White/Green wire). If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in White/Green wire. Go to step  27 .

  24. Check circuits for short

    Measure resistance between harness side of OCS pressure sensor connector C3042, terminals "C" (Yellow/Green wire) and "B" (White/Green wire). Measure resistance between harness side of OCS pressure sensor connector C3042, terminals "C" (Yellow/Green wire) and "A" (Brown/Green wire). Measure resistance between harness side of OCS pressure sensor connector C3042, terminals "A" (Brown/Green wire) and "B" (White/Green wire). If resistance is more than one megohm between all circuits, go to next step. If resistance is less one megohm between any circuit, repair short between appropriate wires. Go to step  27 .
    NOTE: Ensure all air bag system simulators, sensor electrical connectors and RCM electrical connectors are connected prior to carrying out on-demand self-test or erroneous faults may be set.

  25. Check OCS

    Install NEW OCS system service kit. Reconnect RCM connectors. Zero OCS. See ZERO OCCUPANT CLASSIFICATION SENSOR (OCS)  under DIAGNOSTICS. Turn ignition switch to ON position. Perform on-demand self-test. Flag DTC B2290. Retrieve and record any flagged faults. If flagged fault "?" was retrieved during on-demand self-test, multiple faults exist and all steps of diagnostic procedure must be performed. If DTC B2290 was retrieved during on-demand self-test, replace RCM. Go to step  27 . If DTC B2290 was retrieved during on-demand self-test, fault is corrected. Go to step  27 .

  26. Check for intermittent fault

    Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Turn ignition switch to ON position. Perform on-demand self-test. If flagged fault "?" was retrieved during on-demand self-test in step  1 , multiple faults exist and all steps of diagnostic procedure must be performed. On models equipped with original part OCS, if DTC B2290 was retrieved during on-demand self-test, fault is hard.
    • For communication (COMM) fault, go to step  2 .
    • For internal (INT) fault, replace OCS system. See OCCUPANT CLASSIFICATION SENSOR (OCS)  under REMOVAL & INSTALLATION. Go to next step.
    • For calibration fault, replace OCS system. Go to next step.
    • For OCS pressure sensor fault, go to step  18 .

      On models equipped with service part OCS, if DTC B2290 was retrieved during on-demand self-test, fault is hard.

    • For communication (COMM) fault, go to step  2 .
    • For internal (INT) fault, replace OCS system. See OCCUPANT CLASSIFICATION SENSOR (OCS)  under REMOVAL & INSTALLATION. Go to next step.
    • For calibration fault, replace OCS system. Go to next step.
    • For OCS pressure sensor fault, replace OCS system. Go to next step.

      If DTC B2290 was not retrieved during on-demand self-test, check for cause of intermittent fault. Attempt to recreate fault by flexing wire harness and cycling ignition switch frequently. Repair any intermittent problems found. Go to next step.

  27. 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.
Fig 1: Identifying Occupant Classification Sensor (OCS) Module Connector C3043
G99F27412Courtesy of FORD MOTOR CO.
Fig 2: Identifying Right Front Seat Harness Connector C3047
G99I28173Courtesy of FORD MOTOR CO.
Fig 3: Identifying Occupant Classification Sensor (OCS) Pressure Sensor Connector C3042 Terminals
G99E27478Courtesy of FORD MOTOR CO.
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