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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 927 (Supplemental Inflatable Restraint System -- F250-F550 Super Duty) >> Diagnosis And Testing >> Pinpoint Tests - Air Bag Supplemental Restraint System (SRS) >> Pinpoint Test D: LFC 25/DTC B1871 - Passenger Air Bag Deactivate Module Fault >> Pinpoint Test D: LFC 25/DTC B1871 - Passenger Air Bag Deactivate Module Fault

Pinpoint Test D: LFC 25/DTC B1871 - Passenger Air Bag Deactivate Module Fault

WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. 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 a thorough Inspection and Verification before proceeding with the Pinpoint Test.
  1. D1 CHECK FOR ON-DEMAND AND CONTINUOUS 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.
    NOTE: After diagnosing or repairing a supplemental restraint system (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.
    • Enter the following diagnostic mode on the diagnostic tool: Retrieve/Record On-Demand DTCs.
    • Enter the following diagnostic mode on the diagnostic tool: Retrieve/Record Continuous DTCs.
    • Was DTC B1871 retrieved during the on-demand self test? 
    • Yes  : This is a hard fault. The fault condition is still present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self test. GO to D2.
    • No  : This is an intermittent fault. The fault condition is not present at this time. GO to  D6.
  2. D2 CHECK THE PAD SWITCH "ON" POSITION 
    • Key in OFF position.
    • Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING  in this article.
    • Disconnect: RCM C2041.
    • Place the PAD switch in the "ON" position.
    • Measure the resistance between RCM C2041 pin 8, circuit 1112 (WH/LB), harness side and RCM C2041 pin 21, circuit 649 (BK/OG), harness side.
      Fig 1: Measuring Resistance Between RCM C2041 Pin 8 Circuit 1112 And RCM C2041 Pin 21 Circuit 649 Harness Side
      G03926207Courtesy of FORD MOTOR CO.
    • Is the resistance between 900 and 1100 ohms? 
    • Yes  : GO to D3.
    • No  : GO to  D4.
  3. D3 CHECK THE PAD SWITCH "OFF" POSITION 
    • Place the PAD switch in the "OFF" position.
    • Measure the resistance between RCM C2041 pin 8, circuit 1112 (WH/LB), harness side and RCM C2041 pin 21, circuit 649 (BK/OG), harness side.
      Fig 2: Measuring Resistance Between RCM C2041 Pin 8 Circuit 1112 And RCM C2041 Pin 21 Circuit 649
      G03926207Courtesy of FORD MOTOR CO.
    • Is the resistance between 400 and 600 ohms? 
  4. D4 CHECK CIRCUIT 1112 (WH/LB) FOR A SHORT TO BATTERY 
    • Disconnect: PAD Switch C2099.
    • Repower the system. Do not  prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING  in this article.
    • Key in ON position.
    • Measure the voltage between PAD C2099 pin 6, circuit 1112 (WH/LB), harness side and ground.
      Fig 3: Measuring Voltage Between Pad C2099 Pin 6 Circuit 1112 Harness Side And Ground
      G03926209Courtesy of FORD MOTOR CO.
    • Is the voltage less than 0.2 volt? 
    • Yes  : GO to D5.
    • No  : REPAIR circuit 1112 (WH/LB). GO to  D7.
  5. D5 CHECK CIRCUIT 1112 (WH/LB) FOR AN OPEN 
    • Key in OFF position.
    • Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING  in this article.
    • Measure the resistance between RCM C2041 pin 8, circuit 1112 (WH/LB), harness side and PAD switch C2099 pin 6, circuit 1112 (WH/LB), harness side.
      Fig 4: Measuring Resistance Between RCM C2041 Pin 8 Circuit 1112 Harness Side And Pad Switch C2099 Pin 6 Circuit 1112
      G03926210Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
  6. D6 CHECK FOR AN INTERMITTENT FAULT 
    • Key in OFF position.
    • Enter the following diagnostic mode on the diagnostic tool: On-Demand Self Test.
    • Was DTC B1871 retrieved during the on-demand self test? 
    • Yes  : This is a hard fault. The fault condition is now present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self test. GO to  D2.
    • No  : CHECK for causes of intermittent faults on circuit 1112 (WH/LB). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. REPAIR any intermittent concerns found. GO to D7.
  7. D7 CHECK FOR ADDITIONAL DTCs 
    • Refer to the continuous DTCs recorded during Step  D1.
    • Were any continuous DTCs retrieved during Step   D1 ? 
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