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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 1965 (Auxiliary Brake System) >> Diagnostic Tests >> Auxiliary Brake System - Trailer Brake Control (TBC) Module >> Pinpoint Tests >> Pinpoint Test C: DTCs C2797, C2798, C2800, C2801 And C2803 - Brake Pressure Transducer Circuit Failure >> PINPOINT TEST C: DTCs C2797, C2798, C2800, C2801 AND C2803 - BRAKE PRESSURE TRANSDUCER CIRCUIT FAILURE

PINPOINT TEST C: DTCs C2797, C2798, C2800, C2801 AND C2803 - BRAKE PRESSURE TRANSDUCER CIRCUIT FAILURE

WARNING: This page is about a different car, the 2007 Ford Pickup, 2007 Ford F550 Super Duty, 2007 Ford F450 Super Duty, and 2007 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.
NOTE: If there is no brake pressure transducer mounted on the brake master cylinder, then the system was not correctly installed. Warranty repairs on incorrectly installed trailer brake systems will not be covered by Ford Motor Company.
  1. C1 CHECK THE DTCs 
    • Connect the diagnostic tool.
    • Key in ON position.
    • Clear the DTCs and cycle the ignition switch.
    • Retrieve the DTCs.
    • Did DTC C2797, C2798, C2800, C2801 or C2803 return? 
    1. YES  : For DTC C2797, go to  C7 .

      For DTC C2798 and C2801, go to  C9 .

      For DTC C2800, INSPECT the brake master cylinder for the presence of a brake pressure transducer. If a transducer is present, go to  C7 . If a transducer is not present, go to Pinpoint Test H .

      For DTC C2803, go to  C2 .

    2. NO  : If other DTCs are retrieved, go to Trailer Brake Control (TBC) Module Diagnostic Trouble Code (DTC) Index and continue diagnostics.

      If no DTCs returned, the customer trailer may be at fault. SEND the trailer to an authorized camper/trailer repair center.

  2. C2 CHECK THE TBC BOO PID 
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: TBC BOO PID
    • Monitor the TBC BOO PID while firmly pressing and releasing the brake pedal.
    • Does the TBC BOO PID agree with the stoplamp switch? 
    1. YES  : Go to  C3.
    2. NO  : VERIFY that the stoplamp switch is OK. If OK, go to  C12 . If not OK, REFER to EXTERIOR LIGHTING article for stoplamp switch diagnostics.
  3. C3 CHECK THE BRAKE PRESSURE SWITCH 
    • Key in OFF position.
    • Disconnect: Powertrain Control Module C175a (Gasoline)
    • Disconnect: Powertrain Control Module C1381a (Diesel)
    • Key in ON position.
    • For gasoline engine equipped vehicles  , measure the voltage between powertrain control module (PCM) C175a-65, circuit 307 (BK/YE), harness side and ground while firmly applying and releasing the brake pedal.
      • Fig 1: Checking Brake Pressure Switch (Gasoline Engine)
      GF0006740Courtesy of FORD MOTOR CO.
    • For diesel engine equipped vehicles  , measure the voltage between PCM C1381a-28, circuit 307 (BK/YE), harness side and ground while firmly applying and releasing the brake pedal.
      • Fig 2: Checking Brake Pressure Switch (Diesel Engine)
      GF0006741Courtesy of FORD MOTOR CO.
    • Is the voltage 0 volt with the brake pedal firmly applied and greater than 10 volts with the brake pedal released? 
    1. YES  : Go to  C12.
    2. NO  : Go to  C4.
  4. C4 CHECK CIRCUIT 418 (DG/YE) FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: Brake Pressure Switch C1025
    • Key in ON position.
      • NOTE: Do not press the brake pedal while measuring the voltage.
    • Measure the voltage between brake pressure switch C1025-1, circuit 418 (DG/YE), harness side and ground.
      • Fig 3: Checking Circuit 418 (DG/YE) For Open
      GF0006742Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts without pressing the brake pedal? 
    1. YES  : Go to  C5.
    2. NO  : VERIFY BJB fuse 12 (2A) is OK. If OK, REPAIR circuit 418 (DG/YE). CLEAR the DTCs. REPEAT the self-test.
  5. C5 CHECK CIRCUIT 307 (BK/YE) FOR A SHORT TO VOLTAGE 
    • Measure the voltage between brake pressure switch C1025-2, circuit 307 (BK/YE), harness side and ground.
      • Fig 4: Checking Circuit 307 (BK/YE) For Short To Voltage
      GF0006743Courtesy of FORD MOTOR CO.
    • Is voltage present? 
    1. YES  : REPAIR circuit 307 (BK/YE). CLEAR the DTCs. REPEAT the self-test.
    2. NO  : Go to  C6.
  6. C6 CHECK CIRCUIT 307 (BK/YE) FOR AN OPEN 
    • Key in OFF position.
    • For gasoline engine equipped vehicles  , measure the resistance between brake pressure switch C1025-2, circuit 307 (BK/YE), harness side and PCM C175a-65, circuit 307 (BK/YE), harness side.
      • Fig 5: Checking Circuit 307 (BK/YE) For Open (Gasoline Engine)
      GF0006744Courtesy of FORD MOTOR CO.
    • For diesel engine equipped vehicles  , measure the resistance between brake pressure switch C1025-2, circuit 307 (BK/YE), harness side and PCM C1381a-28, circuit 307 (BK/YE), harness side.
      • Fig 6: Checking Circuit 307 (BK/YE) For Open (Diesel Engine)
      GF0006745Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. YES  : INSTALL a new brake master cylinder. REFER to HYDRAULIC BRAKE ACTUATION article. CLEAR the DTCs. REPEAT the self-test.
    2. NO  : REPAIR circuit 307 (BK/YE). CLEAR the DTCs. REPEAT the self-test.
  7. C7 CHECK CIRCUIT 3602 (TN/YE) FOR A SHORT TO VOLTAGE 
    • Key in OFF position.
    • Disconnect: TBC Module C2142b
    • Disconnect: Brake Pressure Transducer C1445
    • Key in ON position.
    • Measure the voltage between C1445-3, circuit 3602 (TN/YE), harness side and ground.
      • Fig 7: Checking Circuit 3602 (TN/YE) For Short To Voltage
      GF0006746Courtesy of FORD MOTOR CO.
    • Is voltage present? 
    1. YES  : REPAIR circuit 3602 (TN/YE). CLEAR the DTCs. REPEAT the self-test.
    2. NO  : Go to  C8.
  8. C8 CHECK CIRCUIT 3602 (TN/YE) FOR A SHORT TO VOLTAGE 
    • Key in OFF position.
    • Connect: TBC Module C2142b
    • Key in ON position.
    • Measure the voltage between C1445-3, circuit 3602 (TN/YE), harness side and ground.
      • Fig 8: Checking Circuit 3602 (TN/YE) For Short To Voltage
      GF0006746Courtesy of FORD MOTOR CO.
    • Is voltage present? 
    1. YES  : If the voltage is greater than 6 volts, go to  C16 .

      If the voltage is less than 6 volts, attempt to recreate the DTC by flexing the wire harness at the brake pressure transducer. If the DTC returns, REPAIR the affected circuit(s). If the DTC does not return, CHECK the brake pressure transducer connector for corrosion, pushed-out pins and spread terminals. REPAIR the brake pressure transducer connector if necessary.

      If the brake pressure transducer connector is OK, INSTALL a new master cylinder. REFER to HYDRAULIC BRAKE ACTUATION article. CLEAR the DTCs. REPEAT the self-test.

    2. NO  : If lead here by DTC C2797, go to  C13 .

      If lead here by DTC C2800, go to  C10 .

  9. C9 CHECK CIRCUIT 3602 (TN/YE) FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Disconnect: TBC Module C2142b
    • Disconnect: Brake Pressure Transducer C1445
    • Measure the resistance between TBC module C2142b-10, circuit 3602 (TN/YE), harness side and ground.
      • Fig 9: Checking Circuit 3602 (TN/YE) For Short To Ground
      GF0006747Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : If lead here by DTC C2798, go to  C15 . If lead here by DTC C2801, go to  C11 .
    2. NO  : REPAIR circuit 3602 (TN/YE). CLEAR the DTCs. REPEAT the self-test.
  10. C10 CHECK THE BRAKE PRESSURE TRANSDUCER CIRCUITS FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: TBC Module C2142b
    • Disconnect: Brake Pressure Transducer C1445
    • Measure the resistance between:
      • TBC module C2142b-8, circuit 3600 (RD/WH), harness side and brake pressure transducer C1445-1, circuit 3600 (RD/WH), harness side.
      • TBC module C2142b-9, circuit 3601 (WH/RD), harness side and brake pressure transducer C1445-2, circuit 3601 (WH/RD), harness side.
      • TBC module C2142b-10, circuit 3602 (TN/YE), harness side and brake pressure transducer C1445-3, circuit 3602 (TN/YE), harness side.
      • Fig 10: Checking Brake Pressure Transducer Circuits For Open
      GF0006748Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    1. YES  : Go to  C13.
    2. NO  : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
  11. C11 CHECK CIRCUIT 3601 (WH/RD) FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Disconnect: TBC Module C2142b
    • Disconnect: Brake Pressure Transducer C1445
    • Measure the resistance between TBC module C2142b-9, circuit 3601 (WH/RD), harness side and ground.
      • Fig 11: Checking Circuit 3601 (WH/RD) For Short To Ground
      GF0006749Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  C15.
    2. NO  : REPAIR circuit 3601 (WH/RD). CLEAR the DTCs. REPEAT the self-test.
  12. C12 CHECK CIRCUIT 3601 (WH/RD) FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: TBC Module C2142b
    • Disconnect: Brake Pressure Transducer C1445
    • Measure the resistance between TBC module C2142b-9, circuit 3601 (WH/RD), harness side and brake pressure transducer C1445-2, circuit 3601 (WH/RD), harness side.
      • Fig 12: Checking Circuit 3601 (WH/RD) For An Open
      GF0006750Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. YES  : CHECK the brake pressure transducer connector for corrosion, pushed-out pins and spread terminals. REPAIR the connector as necessary. Attempt to recreate the DTC by flexing the wire harness at the brake pressure transducer. If the DTC returns, REPAIR the affected circuit(s). If the DTC does not return, INSTALL a new master cylinder. REFER to HYDRAULIC BRAKE ACTUATION article. CLEAR the DTCs. REPEAT the self-test.
    2. NO  : REPAIR circuit 3601 (WH/RD). CLEAR the DTCs. REPEAT the self-test.
  13. C13 CHECK CIRCUIT 3601 (WH/RD) FOR A SHORT TO VOLTAGE 
    • Key in OFF position.
    • Disconnect: TBC Module C2142b
    • Disconnect: Brake Pressure Transducer C1445
    • Key in ON position.
    • Measure the voltage between brake pressure transducer C1445-2, circuit 3601 (WH/RD), harness side and ground.
      • Fig 13: Checking Circuit 3601 (WH/RD) For Short To Voltage
      GF0006751Courtesy of FORD MOTOR CO.
    • Is voltage present? 
    1. YES  : REPAIR circuit 3601 (WH/RD). CLEAR the DTCs. REPEAT the self-test.
    2. NO  : Go to  C14.
  14. C14 CHECK CIRCUIT 3602 (TN/YE) FOR A SHORT TO VOLTAGE 
    • Key in OFF position.
    • Connect: TBC Module C2142b
    • Disconnect: Brake Pressure Transducer C1445
    • Key in ON position.
      • NOTE: Do not press the brake pedal while measuring the voltage.
    • Measure the voltage between brake pressure transducer C1445-2, circuit 3601 (WH/RD), harness side and ground.
      • Fig 14: Measuring Voltage Between Brake Pressure Transducer C1445-2, Circuit 3601 (WH/RD), Harness Side And Ground
      GF0006751Courtesy of FORD MOTOR CO.
    • Is voltage present without pressing the brake pedal? 
    1. YES  : Go to  C16.
    2. NO  : CHECK the brake pressure transducer connector for corrosion, pushed-out pins and spread terminals. REPAIR the connector as necessary. Attempt to recreate the DTC by flexing the wire harness at the brake pressure transducer. If the DTC returns, REPAIR the affected circuit(s). If the DTC does not return, INSTALL a new master cylinder. REFER to HYDRAULIC BRAKE ACTUATION article. CLEAR the DTCs. REPEAT the self-test.
  15. C15 CHECK CIRCUIT 3600 (RD/WH) FOR A SHORT TO VOLTAGE 
    • Connect: TBC Module C2142b
    • Key in ON position.
    • Measure the voltage between brake pressure transducer C1445-1, circuit 3600 (RD/WH), harness side and ground.
      • Fig 15: Checking Circuit 3600 (RD/WH) For Short To Voltage
      GF0006752Courtesy of FORD MOTOR CO.
    • Is voltage present? 
    1. YES  : CHECK the brake pressure transducer connector for corrosion, pushed-out pins and spread terminals. REPAIR the connector as necessary. Attempt to recreate the DTC by flexing the wire harness at the brake pressure transducer. If the DTC returns, REPAIR circuit 3600 (RD/WH). If the DTC does not return, INSTALL a new master cylinder. REFER to HYDRAULIC BRAKE ACTUATION article. CLEAR the DTCs. REPEAT the self-test.
    2. NO  : Go to  C16.
  16. C16 CHECK FOR CORRECT TBC MODULE OPERATION 
    • Key in OFF position.
    • Disconnect all the TBC module connectors.
    • Check for:
      • corrosion.
      • pushed-out pins.
      • spread terminals.
    • Connect all the TBC module connectors and make sure that they are seated correctly.
    • Operate the system and verify the concern is still present.
    • Is the concern still present? 
    1. YES  : INSTALL a new TBC module. REFER to Trailer Brake Control (TBC) Module  in this article. CLEAR the DTCs. REPEAT the self-test.
    2. NO  : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
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