LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2000 >> Contour SE, 2.0 3, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 794 (Supplemental Restraint System) >> Diagnosis And Testing >> Pinpoint Tests - Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) >> PINPOINT TEST V: LFC 72/DTC B2792 - Cross Link Between Firing Loops >> Pinpoint Test V: LFC 72/DTC B2792 - Restraint System - Cross Link Circuit Failure

Pinpoint Test V: LFC 72/DTC B2792 - Restraint System - Cross Link Circuit Failure

WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Most faults are due to connector and/or wiring concerns. Carry out thorough Inspection and Verification  before proceeding with the Pinpoint Test.
  1. V1 CHECK FOR CONTINUOUS AND ON-DEMAND DTCs 
    WARNING: Restraint system diagnostic tools are for service only. Tools must be removed prior to operating the vehicle over the road. Failure to remove restraint system diagnostic tools could result in injury and possible violation of vehicle safety standards.
    WARNING: Never probe the connectors on the air bag module. Doing so can result in air bag deployment, which can result in personal injury.
    WARNING: The safety belt pretensioner is a pyrotechnic device. Always wear safety glasses when repairing an air bag equipped vehicle and when handling a safety belt buckle pretensioner or safety belt retractor pretensioner. Never probe a pretensioner electrical connector. Doing so could result in pretensioner or air bag deployment and could result in personal injury.
    CAUTION: To avoid potential damage to the restraints control module (RCM), make sure the RCM and bracket assembly is secured to the floor pan and the SRS is depowered before either disconnecting or reconnecting the RCM electrical connectors.
    NOTE: After diagnosing or repairing an SRS, the restraint system diagnostic tools must be removed before operating the vehicle over the road.
    NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
    • Key in OFF position.
    • Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
    • Remove the driver air bag module. Refer to DRIVER AIR BAG MODULE .
    • Attach restraint system diagnostic tool 418-F395 to the clockspring side of the driver air bag module electrical connector.
    • Disconnect: Passenger Air Bag Module C256.
    • Attach restraint system diagnostic tool 418-133 to the passenger air bag module C256.
    • Repower the system. Do not  prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
    • Enter the following diagnostic mode on the scan tool: Retrieve/Record all Continuous and On-Demand DTCs.
    • Enter the following diagnostic mode on the scan tool: Clear All DTCs.
    • Cycle the ignition OFF then ON.
    • Enter the following diagnostic mode on the scan tool: Retrieve All Continuous and On-Demand DTCs.
    • Was DTC B2792 retrieved continuous along with DTCs B1938, B1879 or B1883? 
    • Yes  : If DTCs B2792 and B1938 are present, GO to V2.

      If DTCs B2792 and B1879 are present, GO to  V3.

      If DTCs B2792 and B1883 are present, GO to  V4.

    • No  : This is an intermittent fault. The fault condition is not present at this time. GO to  V7.
  2. V2 CHECK THE PASSENGER AIR BAG CIRCUITS FOR A SHORT TO THE DRIVER AIR BAG CIRCUITS 
    • Key in OFF position.
    • Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
    • Disconnect: RCM C310a.
    • Disconnect: Driver Air Bag Module Restraint System Diagnostic Tool.
    • Disconnect: Passenger Air Bag Module Restraint System Diagnostic Tool.
    • Check the passenger air bag module circuits for a short to the driver air bag module circuits by carrying out the following:
      • Measure the resistance between RCM C310a pin 3, circuit 607 (LB/OG), harness side and the RCM C310a pin 1, circuit 614 (GY/OG), harness side.
      • Measure the resistance between RCM C310a pin 3, circuit 607 (LB/OG), harness side and the RCM C310a pin 2, circuit 615 (GY/WH), harness side.
      • Measure the resistance between RCM C310a pin 4, circuit 616 (PK/BK), harness side and the RCM C310a pin 1, circuit 614 (GY/OG), harness side.
      • Measure the resistance between RCM C310a pin 4, circuit 616 (PK/BK), harness side and the RCM C310a pin 2, circuit 615 (GY/WH), harness side.
        Fig 1: Checking Passenger Air Bag Module Circuits
        G03891322Courtesy of FORD MOTOR CO.
    • Are the resistances greater than 10,000 ohms? 
    • Yes  : GO to  V6.
    • No  : REPAIR short in circuit 607 (LB/OG), circuit 614 (GY/OG), circuit 615 (GY/WH), or circuit 616 (PK/BK). GO to  V8.
  3. V3 CHECK THE DRIVER SAFETY BELT BUCKLE PRETENSIONER CIRCUITS FOR A SHORT TO THE DRIVER OR PASSENGER AIR BAG CIRCUITS 
    • Key in OFF position.
    • Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
    • Disconnect: RCM C310b.
    • Disconnect: RCM C310a.
    • Disconnect: Driver Safety Belt Buckle Pretensioner C323.
    • Disconnect: Driver Air Bag Module Restraint System Diagnostic Tool.
    • Disconnect: Passenger Air Bag Module Restraint System Diagnostic Tool.
    • Check the driver safety belt buckle pretensioner circuits for a short to the driver air bag module circuits and the passenger air bag module circuits by carrying out the following:
      • Measure the resistance between RCM C310b pin 17, circuit 1079 (LG/RD), harness side and the RCM C310a pin 1, circuit 614 (GY/OG), harness side.
      • Measure the resistance between RCM C310b pin 17, circuit 1079 (LG/RD), harness side and the RCM C310a pin 2, circuit 615 (GY/WH), harness side.
      • Measure the resistance between RCM C310b pin 18, circuit 1080 (LG/BK), harness side and the RCM C310a pin 1, circuit 614 (GY/OG), harness side.
      • Measure the resistance between RCM C310b pin 18, circuit 1080 (LG/BK), harness side and the RCM C310a pin 2, circuit 615 (GY/WH), harness side.
      • Measure the resistance between RCM C310b pin 17, circuit 1079 (LG/RD), harness side and the RCM C310a pin 3, circuit 607 (LB/OG), harness side.
      • Measure the resistance between RCM C310b pin 17, circuit 1079 (LG/RD), harness side and the RCM C310a pin 2, circuit 616 (PK/BK), harness side.
      • Measure the resistance between RCM C310b pin 18, circuit 1080 (LG/BK), harness side and the RCM C310a pin 3, circuit 607 (LB/OG), harness side.
      • Measure the resistance between RCM C310b pin 18, circuit 1080 (LG/BK), harness side and the RCM C310a pin 2, circuit 616 (PK/BK), harness side.
        Fig 2: Checking Driver Safety Belt Buckle Pretensioner Circuits For Short To Driver Or Passenger Air Bag Circuits
        G03891323Courtesy of FORD MOTOR CO.
    • Are the resistances greater than 10,000 ohms? 
    • Yes  : GO to  V6.
    • No  : REPAIR short in circuit 1079 (LG/RD), circuit 1080 (LG/BK), circuit 614 (GY/OG), circuit 615 (GY/WH), circuit 607 (LB/OG) and/or circuit 616 (PK/BK). GO to  V8.
  4. V4 CHECK THE PASSENGER SAFETY BELT BUCKLE PRETENSIONER CIRCUITS FOR A SHORT TO THE DRIVER SAFETY BELT BUCKLE PRETENSIONER CIRCUITS 
    • Key in OFF position.
    • Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
    • Disconnect: RCM C310b.
    • Disconnect: Passenger Safety Belt Buckle Pretensioner C303.
    • Disconnect: Driver Safety Belt Buckle Pretensioner C323.
    • Check the passenger safety belt pretensioner circuits for a short to the driver pretensioner circuits by carrying out the following:
      • Measure the resistance between RCM C310b pin 35, circuit 1081 (YE/RD), harness side and the RCM C310b pin 17, circuit 1079 (LG/RD), harness side.
      • Measure the resistance between RCM C310b pin 35, circuit 1081 (YE/RD), harness side and the RCM C310b pin 18, circuit 1080 (LG/BK), harness side.
      • Measure the resistance between RCM C310b pin 36, circuit 1082 (LB/BK), harness side and the RCM C310b pin 17, circuit 1079 (LG/RD), harness side.
      • Measure the resistance between RCM C310b pin 36, circuit 1082 (LB/BK), harness side and the RCM C310b pin 18, circuit 1080 (LG/BK), harness side.
        Fig 3: Checking Passenger Safety Belt Pretensioner Circuits For Short To Driver Pretensioner Circuits
        G03891324Courtesy of FORD MOTOR CO.
    • Are the resistances greater than 10,000 ohms? 
    • Yes  : GO to V5.
    • No  : REPAIR short in circuit 1081 (YE/RD), circuit 1082 (LG/BK), circuit 1079 (LG/RD), and/or circuit 1080 (LG/BK). GO to  V8.
  5. V5 CHECK THE PASSENGER SAFETY BELT BUCKLE PRETENSIONER CIRCUITS FOR A SHORT TO THE DRIVER OR PASSENGER AIR BAG CIRCUITS 
    • Disconnect: Driver Air Bag Module Restraint System Diagnostic Tool.
    • Disconnect: Passenger Air Bag Module Restraint System Diagnostic Tool.
    • Check the passenger safety belt buckle pretensioner circuits for a short to the driver air bag module circuits and passenger air bag module circuits by carrying out the following:
      • Measure the resistance between RCM C310b pin 35, circuit 1081 (YE/RD), harness side and the RCM C310a pin 1, circuit 614 (GY/OG), harness side.
      • Measure the resistance between RCM C310b pin 35, circuit 1081 (YE/RD), harness side and the RCM C310a pin 2, circuit 615 (GY/WH), harness side.
      • Measure the resistance between RCM C310b pin 36, circuit 1082 (LB/RD), harness side and the RCM C310a pin 1, circuit 614 (GY/OG), harness side.
      • Measure the resistance between RCM C310b pin 36, circuit 1082 (LB/RD), harness side and the RCM C310a pin 2, circuit 615 (GY/WH), harness side.
      • Measure the resistance between RCM C310b pin 35, circuit 1081 (YE/RD), harness side and the RCM C310a pin 3, circuit 607 (LB/OG), harness side.
      • Measure the resistance between RCM C310b pin 35, circuit 1081 (YE/RD), harness side and the RCM C310a pin 4, circuit 616 (PK/BK), harness side.
      • Measure the resistance between RCM C310b pin 36, circuit 1082 (LB/RD), harness side and the RCM C310a pin 3, circuit 607 (LB/OG), harness side.
      • Measure the resistance between RCM C310b pin 36, circuit 1082 (LB/RD), harness side and the RCM C310a pin 4, circuit 616 (PK/BK), harness side.
        Fig 4: Checking Passenger Safety Belt Buckle Pretensioner Circuits For Short To Driver Air Bag Module Circuits And Passenger Air Bag Module Circuits
        G03891325Courtesy of FORD MOTOR CO.
    • Are the resistances greater than 10,000 ohms? 
    • Yes  : GO to V6.
    • No  : REPAIR short in circuit 1081 (YE/RD), circuit 1082 (LB/RD), circuit 614 (GY/OG), circuit 615 (GY/WH), circuit 607 (LB/OG) and/or circuit 616 (PK/BK). GO to  V8.
  6. V6 CONFIRM THE RCM FAULT 
    NOTE: Make sure all restraint system diagnostic tools, sensor electrical connectors and the RCM electrical connectors are connected before carrying out the on-demand self test. If not, erroneous DTCs will be recorded.
    • Connect: RCM C310b.
    • Connect: RCM C310a.
    • Connect: Driver Air Bag Module Restraint System Diagnostic Tool.
    • Connect: Passenger Air Bag Module Restraint System Diagnostic Tool.
    • Connect: Passenger Safety Belt Buckle Pretensioner (if previously disconnected).
    • Connect: Driver Safety Belt Buckle Pretensioner (if previously disconnected).
    • Repower the system. Do not  prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
    • Key in ON position.
    • Enter the following diagnostic mode on the scan tool: Retrieve Continuous DTCs.
    • Was DTC B2792 retrieved? 
    • Yes  : INSTALL a new RCM. REFER to RESTRAINTS CONTROL MODULE (RCM) . GO to  V8.
    • No  : CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. ACTIVATE other systems in the same wire harness. REPAIR any intermittent concerns found. GO to  V8.
  7. V7 CHECK FOR AN INTERMITTENT FAULT 
    • Clear all DTCs.
    • Cycle the ignition OFF then ON.
    • Enter the following diagnostic mode on the scan tool: Retrieve Continuous DTCs.
    • Was DTC B2227 retrieved during the on-demand self test? 
    • Yes  : This is a hard fault. The fault condition is now present. The fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self test. GO to V8.
    • No  : CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. ACTIVATE other systems in the same wire harness. REPAIR any intermittent concerns found. GO to V8.
  8. V8 CHECK FOR ADDITIONAL DTCs 
    • Clear all DTCs.
    • Cycle the ignition OFF then ON.
    • Enter the following diagnostic mode on the scan tool: Retrieve all Continuous and On-Demand DTCs.
    • Were additional DTCs retrieved? 
scientia non olet · About LEMON Manuals