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Home >> Lincoln >> 2018 >> Navigator L Select, 4WD >> Repair and Diagnosis >> Restraints >> Restraints Control Systems >> RCM Guided Routine Testing -- (3 Of 4) >> Pinpoint Tests >> Pinpoint Test FA: Driver Buckle Sensor >> Visual Inspection and Diagnostic Pre-checks

Visual Inspection and Diagnostic Pre-checks

WARNING: Incorrect repair techniques or actions can cause an accidental SRS deployment. Never compromise or depart from these instructions. Failure to precisely follow all instructions could result in serious personal injury from an accidental deployment.
CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test.
NOTE: Only disconnect or reconnect SRS components when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS.
NOTE: Always make sure the correct SRS component is being installed. Parts released for other vehicles may not be compatible even if they appear physically similar. Check the part number listed in the Ford parts catalog to make sure the correct component is being installed. If an incorrect SRS component is installed, DTCs may set.
NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
Fig 1: Restraint Control Module-B (RCM-B) Connector End View (C310B)
G12765561Courtesy of FORD MOTOR CO.
Harness Side

Circuit Pin
DRV_SBLT_BCKL_SN_FD (Driver Seatbelt Buckle Sensor Feed) - CR201 54 (GREEN/BLUE)
SNSR_RTN (Sensor Return) - RR172 53 (GREEN/VIOLET)
Fig 2: Driver Seatbelt Buckle Switch Connector End View (C3201)
G12765562Courtesy of FORD MOTOR CO.
Harness Side

Circuit Pin
DRV_SBLT_BCKL_SN_FD (Driver Seatbelt Buckle Sensor Feed) - CR201 5 (GREEN/BLUE)
  1. FA1: CHECK FOR DTC U3003:16 AND U3003:17 
    WARNING: Before beginning any service procedure in this article, refer to Safety Warnings in General Information article. Failure to follow this instruction may result in serious personal injury.
    NOTE: Diagnose all network-related (lost communication) DTCs first.
    • Ignition ON, engine OFF.
    • Carry out the RCM self-test.
    • Is DTC U3003:16 or U3003:17 retrieved DTC during the self-test? 
      Yes No
      REFER to the DTC Chart. Go to  FA2.
  2. FA2: RETRIEVE RCM DTCS 
    • Ignition ON, engine OFF.
    • Carry out the RCM self-test.
    • Is DTC B0050:11, B0050:12, B0050:13 and B0050:1D retrieved as an on-demand (not continuous) DTC during the self-test? 
      Yes No
      This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self-test.
      For DTC B0050:11 or B0050:1D, Go to  FA3.
      For DTC B0050:12, Go to  FA5.
      For DTC B0050:13, Go to  FA6.
      For all others,
      No fault found.      		 This is an intermittent fault when present as a CMDTC only.
      Go to  FA12.
  3. FA3: CHECK THE DRIVER SEATBELT BUCKLE SWITCH DTC FOR A FAULT STATUS CHANGE (SHORT TO GROUND OR CURRENT OUT OF RANGE INDICATED) 
    NOTE: This pinpoint test step attempts to change the fault reported by the RCM by inducing a different fault condition. If the reported fault changes, this indicates the RCM is functioning correctly and is not the source of the fault.
    • Ignition OFF.
    • Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering in Supplemental Restraint System article.
    • Driver Seatbelt Buckle Switch connector disconnected. (C3201)
    • Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Repowering in Supplemental Restraint System article.
    • Ignition ON, engine OFF.
    • Carry out the RCM self-test.
      NOTE: When viewing DTCs with the driver seatbelt buckle switch disconnected, an open circuit fault is normally retrieved.
    • Does the on-demand DTC change from B0050:11 or B0050:1D to B0050:13? 
      Yes No
      Go to  FA9. For DTC B0050:11, Go to  FA4.
      For DTC B0050:1D, Go to  FA10.
      For all others,
      No fault found.
  4. FA4: CHECK THE DRIVER SEATBELT BUCKLE SWITCH CIRCUIT FOR A SHORT TO GROUND 
    • Ignition OFF.
    • Depower the SRS. REFER to the Supplemental Restraint System (SRS) Depowering in the General Procedures portion of Supplemental Restraint System article.
    • RCM_A connector disconnected. (C310A)
    • RCM_B connector disconnected. (C310B)
    • Measure the resistance between:
      (+) Driver Seatbelt Buckle Switch (C3201) Connector, Harness Side (-)
      DRV_SBLT_BCKL_SN_FD - CR201 (GREEN/BLUE) - Pin 5 Ground
    • Is the resistance greater than 10, 000 ohms? 
      Yes No
      Go to  FA10. REPAIR the circuit in question.
      Go to  FA13.
  5. FA5: CHECK THE DRIVER SEATBELT BUCKLE SWITCH CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition OFF.
    • Depower the SRS. REFER to the Supplemental Restraint System (SRS) Depowering in the General Procedures portion of Supplemental Restraint System article.
    • RCM_A connector disconnected. (C310A)
    • RCM_B connector disconnected. (C310B)
    • Driver Side Airbag Assembly connector disconnected.
    • Driver Seatbelt Buckle Switch connector disconnected. (C3201)
    • Repower the SRS. REFER to the Supplemental Restraint System (SRS) Repowering in the General Procedures portion of Supplemental Restraint System article.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) Driver Seatbelt Buckle Switch (C3201) Connector, Harness Side (-)
      DRV_SBLT_BCKL_SN_FD - CR201 (GREEN/BLUE) - Pin 5 Ground
    • Is any voltage present? 
      Yes No
      REPAIR the circuit in question.
      Go to  FA13.      		 Go to  FA10.
  6. FA6: CHECK THE DRIVER SEATBELT BUCKLE SWITCH DTC FOR A FAULT STATUS CHANGE (OPEN INDICATED) 
    NOTE: This pinpoint test step attempts to change the fault reported by the RCM by inducing a different fault condition. If the reported fault changes, this indicates the RCM is functioning correctly and is not the source of the fault.
    • Ignition OFF.
    • Depower the SRS. REFER to the Supplemental Restraint System (SRS) Depowering in the General Procedures portion of Supplemental Restraint System article.
    • Driver Side Airbag Assembly connector disconnected.
    • Driver Seatbelt Buckle Switch connector disconnected. (C3201)
    • Connect a 5 amp fused jumper wire between the following:
      Point A
      Driver Seatbelt Buckle Switch (C3201) Connector, Harness Side      		 Point B
      Driver Seatbelt Buckle Switch (C3201) Connector, Harness Side
      DRV_SBLT_BCKL_SN_FD - CR201 (GREEN/BLUE) - Pin 5 SNSR_RTN
    • Repower the SRS. REFER to the Supplemental Restraint System (SRS) Repowering in the General Procedures portion of Supplemental Restraint System article.
    • Ignition ON, engine OFF.
    • Carry out the RCM self-test.
      NOTE: DIAGNOSTIC TIP: When viewing DTCs with the driver seatbelt buckle switch circuits shorted together, a short to ground fault is normally retrieved.
    • Does the on-demand DTC change from B0050:13 to B0050:11? 
      Yes No
      REMOVE the fused jumper wire.
      Go to  FA9.      		 REMOVE the fused jumper wire.
      Go to  FA7.
  7. FA7: CHECK THE DRIVER SEATBELT BUCKLE SWITCH CIRCUIT FOR AN OPEN 
    • Ignition OFF.
    • Depower the SRS. REFER to the Supplemental Restraint System (SRS) Depowering in the General Procedures portion of Supplemental Restraint System article.
    • RCM_A connector disconnected. (C310A)
    • RCM_B connector disconnected. (C310B)
    • Measure the resistance between:
      (+) RCM_B (C310B) Connector, Harness Side (-) Driver Seatbelt Buckle Switch (C3201) Connector, Harness Side
      DRV_SBLT_BCKL_SN_FD - CR201 (GREEN/BLUE) - Pin 54 DRV_SBLT_BCKL_SN_FD - CR201 - Pin 5
    • Is the resistance less than 0.5 ohm? 
      Yes No
      Go to  FA8. REPAIR the circuit in question.
      Go to  FA13.
  8. FA8: CHECK THE DRIVER SEATBELT BUCKLE SWITCH GROUND CIRCUIT FOR AN OPEN (TO RCM) 
    • Measure the resistance between:
      (+) Driver Seatbelt Buckle Switch (C3201) Connector, Harness Side (-) RCM_B (C310B) Connector, Harness Side
      SNSR_RTN SNSR_RTN - RR172 - Pin 53
    • Is the resistance less than 3 ohms? 
      Yes No
      Go to  FA10. REPAIR the circuit in question.
      Go to  FA13.
  9. FA9: CONFIRM THE DRIVER SEATBELT BUCKLE SWITCH FAULT 
    NOTE: Make sure all SRS components and the RCM electrical connectors are connected before carrying out the self-test. If not, DTCs are set.
    • Ignition OFF.
    • Depower the SRS. REFER to the Supplemental Restraint System (SRS) Depowering in the General Procedures portion of Supplemental Restraint System article.
    • Prior to reconnecting any previously disconnected SRS component:
      • inspect connector(s) (including any inline connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
      • inspect wire harness for any damaged, pinched, cut or pierced wires.
      • inspect the RCM electrical Connector Position Assurance (CPA) lever/locks for correct operation.
      • repair any concerns found. Refer to OEM GROUND DISTRIBUTION article, for schematic and connector information.
    • RCM_A connector connected. (C310A)
    • RCM_B connector connected. (C310B)
    • Driver Side Airbag Assembly connector connected. (if previously disconnected).
    • Driver Seatbelt Buckle Switch connector connected. (C3201) Make sure it seats and latches correctly.
    • Repower the SRS. REFER to the Supplemental Restraint System (SRS) Repowering in the General Procedures portion of Supplemental Restraint System article.
    • Ignition ON, engine OFF.
    • Carry out the RCM self-test.
    • Is the original DTC retrieved on-demand during self-test? 
      Yes No
      INSTALL a new driver seatbelt buckle (includes buckle switch). REFER to the appropriate Removal and Installation procedure in Seatbelt Systems article
      Go to  FA13.      		 In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time.
      Install SRS components only when directed to do so in the pinpoint test.
      Go to  FA12.
  10. FA10: CONFIRM THE RCM FAULT 
    NOTE: Make sure all SRS components and the RCM electrical connectors are connected before carrying out the self-test. If not, DTCs are set.
    • Ignition OFF.
    • Depower the SRS. REFER to the Supplemental Restraint System (SRS) Depowering in the General Procedures portion of Supplemental Restraint System article.
    • Prior to reconnecting any previously disconnected SRS component:
      • inspect connector(s) (including any inline connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
      • inspect wire harness for any damaged, pinched, cut or pierced wires.
      • inspect the RCM Connector Position Assurance (CPA) lever/locks for correct operation.
      • repair any concerns found. Refer to OEM GROUND DISTRIBUTION article, for schematic and connector information.
    • RCM_A connector connected. (C310A) (if previously disconnected).
    • RCM_B connector connected. (C310B) (if previously disconnected).
    • Driver Side Airbag Assembly connector connected. (if previously disconnected).
    • Driver Seatbelt Buckle Switch connector connected. (C3201)
    • Repower the SRS. REFER to the Supplemental Restraint System (SRS) Repowering in the General Procedures portion of Supplemental Restraint System article.
    • Ignition ON, engine OFF.
    • Carry out the RCM self-test.
    • Is the original DTC retrieved on-demand during self-test? 
      Yes No
      Go to  FA11. In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time.
      Install SRS components only when directed to do so in the pinpoint test.
      Go to  FA12.
  11. FA11: CONFIRM THE REPAIR 
    • Ignition OFF.
    • CHECK OASIS for any applicable TSBs.
      • If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions.
      • If no TSBs address this concern, INSTALL a new RCM. Refer to the appropriate Removal and Installation procedure in Supplemental Restraint System article.

    INSTALL a new RCM.

    Reconnect all previously disconnected SRS components and repower the SRS. REFER to the Supplemental Restraint System (SRS) Repowering in the General Procedures portion of Supplemental Restraint System article.

    Carry out the OCSM and RCM self-test and record DTCs if present. Do not clear any DTCs until all DTCs have been resolved. DIAGNOSE and REPAIR the RCM and/or OCSM DTCs.

    Carry out the OCSM and RCM self-test and record DTCs if present. Do not clear any DTCs until all DTCs have been resolved.

    If any SRS DTCs are retrieved, DO NOT clear any DTCs until all DTCs have been resolved. DIAGNOSE and REPAIR the RCM and/or OCSM DTCs.

    If no DTCs are retrieved on-demand, the repair is complete. RETURN the vehicle to the customer.

  12. FA12: CHECK FOR AN INTERMITTENT FAULT 
    • Ignition OFF.
    • Depower the SRS. REFER to the Supplemental Restraint System (SRS) Depowering in the General Procedures portion of Supplemental Restraint System article.
    • Driver Seatbelt Buckle Switch connector disconnected. (C3201)
    • Inspect:
      • connector(s) (including any inline connectors) for corrosion, loose or spread terminals and loose or frayed wire connections at terminals.
      • wire harness for any damage, pinched, cut or pierced wires.
      • the RCM Connector Position Assurance (CPA) lever/locks for correct operation. Repair any concerns found. Refer to OEM GROUND DISTRIBUTION article, for schematic and connector information.
    • Connect all previously disconnected component(s)/connector(s).
    • Repower the SRS. REFER to the Supplemental Restraint System (SRS) Repowering in the General Procedures portion of Supplemental Restraint System article.
    • Ignition ON, engine OFF.
    • Carry out the RCM self-test.
    • Is DTC B0050:11, B0050:12, B0050:13 and B0050:1D retrieved on-demand during self-test? 
      Yes No
      This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self-test.
      For DTC B0050:11 or B0050:1D, Go to  FA3.
      For DTC B0050:12, Go to  FA5.
      For DTC B0050:13, Go to  FA6.
      For all others,
      No fault found.      		 The fault is not present and cannot be recreated at this time. Do not install any new SRS components at this time. Install SRS components only when directed to do so in the pinpoint test.
      Go to  FA13.
  13. FA13: CHECK FOR ADDITIONAL SRS DTCS 
    WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
    • Ignition OFF.
    • Depower the SRS. REFER to the Supplemental Restraint System (SRS) Depowering in the General Procedures portion of Supplemental Restraint System article.
    • Reconnect all SRS components (if previously disconnected).
    • Repower the SRS. REFER to the Supplemental Restraint System (SRS) Repowering in the General Procedures portion of Supplemental Restraint System article.
    • Ignition ON, engine OFF.
    • Clear the RCM DTCs.
    • Ignition OFF.
    • Ignition ON, engine OFF.
    • Wait 10 seconds.
    • Carry out the RCM self-test.
    • If equipped with an OCSM, carry out the OCSM self-test.
    • Carry out the OCS self-test.
    • Are any RCM and/or OCSM DTCs retrieved on-demand during self-tests? 
      Yes No
      Do not clear any DTCs until all DTCs have been resolved. DIAGNOSE and REPAIR the RCM and/or OCSM DTCs. The repair is complete. RETURN the vehicle to the customer.
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