LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2009 >> Flex Limited, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1601 (Anti-Lock Brake System - Vehicle Dynamic Systems) >> Diagnostic Tests >> Anti-Lock Control >> Pinpoint Tests >> Pinpoint Test H: DTCs C1278 and C1956 - Steering Angle Sensor Circuit Fault >> PINPOINT TEST H: DTCs C1278 AND C1956 - STEERING ANGLE SENSOR CIRCUIT FAULT

PINPOINT TEST H: DTCs C1278 AND C1956 - STEERING ANGLE SENSOR CIRCUIT FAULT

WARNING: This page is about a different car, the 2009 Mercury Sable, 2009 Ford Taurus X, and 2009 Ford Taurus. 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 multi-meter probes.
CAUTION: Overtightening of the steering wheel rotation sensor fasteners may deform or damage the sensor housing, possibly resulting in faulty operation.
NOTE: Make sure that the steering wheel rotation sensor is mounted securely to the column with 2 fasteners. A loose sensor or missing fastener may result in incorrect sensor operation. Make sure that the sensor connector is mated securely to the harness connector. Before proceeding with electrical testing, make sure that the vehicle battery is fully charged.
  1. H1 CARRY OUT THE CALIBRATION PROCEDURE 
    • Connect the diagnostic tool.
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: Clear the DTCs
    • Carry out the ABS module calibration procedure following the scan tool directions.
    • Test drive the vehicle.
    • Retrieve and record any ABS module DTCs.
    • Are any DTCs retrieved or does the calibration procedure indicate a fault? 
    1. YES  : If DTC C1278 or C1956 is retrieved or if the calibration procedure indicates a fault, go to  H2.

      If any other DTCs are retrieved, go to the ABS Module DTC Table .

    2. NO  : The system is operating correctly at this time. The concern may have been caused by an incorrect ABS module calibration. CLEAR the DTCs. REPEAT the self-test.
  2. H2 MONITOR THE STEERING WHEEL ANGLE (ST_WH_ANG) PID 
    • Enter the following diagnostic mode on the diagnostic tool: DataLogger ABS
    • Monitor the ST_WH_ANG PID while rotating the steering wheel clockwise and counterclockwise very slowly.
    • Does the PID move in intervals of 1 degree? 
    1. YES  : The system is operating correctly at this time. CLEAR the DTCs. REPEAT the self-test.
    2. NO  : Go to  H3.
  3. H3 CHECK FOR VOLTAGE AT THE STEERING WHEEL ROTATION SENSOR 
    • Key in OFF position.
    • Disconnect: Steering Wheel Rotation Sensor C226
    • Key in ON position.
    • Measure the voltage between steering wheel rotation sensor C226-4, circuit CBB38 (GY/BU), harness side and ground.
      • Fig 1: Measuring Voltage
      GF0045790Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 
    1. YES  : Go to  H4.
    2. NO  : VERIFY that BJB fuse 38 (10A) is OK. If OK, REPAIR circuit CBB38 (GY/BU). CALIBRATE the ABS module. FOLLOW the scan tool directions for the calibration procedure. CLEAR the DTCs. REPEAT the self-test.

      If the fuse is open, REFER to the appropriate System Wiring Diagrams article to identify possible causes of the circuit short.

  4. H4 CHECK CIRCUIT RCA09 (GN/VT) FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: ABS Module C135
    • Measure the resistance between steering wheel rotation sensor C226-1, circuit RCA09 (GN/VT), harness side and ABS module C135-12, circuit RCA09 (GN/VT), harness side.
      • Fig 2: Measuring Resistance
      GF0045791Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. YES  : Go to  H5.
    2. NO  : REPAIR circuit RCA09 (GN/VT). CALIBRATE the ABS module. FOLLOW the scan tool directions for the calibration procedure. CLEAR the DTCs. REPEAT the self-test.
  5. H5 CHECK CIRCUITS VCS06 (GY/BN) AND VCS07 (VT/OG) FOR A SHORT TO VOLTAGE 
    • Key in ON position.
    • Measure the voltage between ground and:
      • steering wheel rotation sensor C226-3, circuit VCS07 (VT/OG), harness side.
      • steering wheel rotation sensor C226-2, circuit VCS06 (GY/BN), harness side.
      • Fig 3: Measuring Voltage
      GF0045792Courtesy of FORD MOTOR CO.
    • Is any voltage present? 
    1. YES  : REPAIR the affected circuit(s). CALIBRATE the ABS module. FOLLOW the scan tool directions for the calibration procedure. CLEAR the DTCs. REPEAT the self-test.
    2. NO  : Go to  H6.
  6. H6 CHECK CIRCUITS VCS06 (GY/BN) AND VCS07 (VT/OG) FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Measure the resistance between ground and:
      • steering wheel rotation sensor C226-3, circuit VCS07 (VT/OG), harness side.
      • steering wheel rotation sensor C226-2, circuit VCS06 (GY/BN), harness side.
      • Fig 4: Measuring Resistance
      GF0043886Courtesy of FORD MOTOR CO.
    • Are the resistances greater than 10,000 ohms? 
    1. YES  : Go to  H7.
    2. NO  : REPAIR the affected circuit(s). CALIBRATE the ABS module. FOLLOW the scan tool directions for the calibration procedure. CLEAR the DTCs. REPEAT the self-test.
  7. H7 CHECK CIRCUITS VCS06 (GY/BN) AND VCS07 (VT/OG) FOR AN OPEN 
    • Measure resistance between the steering wheel rotation sensorC226, harness side and ABS module C135, harness side using the following chart:
      Steering Wheel Rotation Sensor Circuit ABS Module
      C226-3 VCS07 (VT/OG) C135-29
      C226-2 VCS06 (GY/BN) C135-8
      • Fig 5: Measuring Resistance
      GF0045793Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. YES  : Go to  H8.
    2. NO  : REPAIR the affected circuit(s). CALIBRATE the ABS module. FOLLOW the scan tool directions for the calibration procedure. CLEAR the DTCs. REPEAT the self-test.
  8. H8 CHECK CIRCUITS VCS06 (GY/BN) AND VCS07 (VT/OG) FOR A SHORT TOGETHER 
    • Measure the resistance between steering wheel rotation sensor C226-3, VCS07 (VT/OG), harness side and steering wheel rotation sensor C226-2, circuit VCS06 (GY/BN), harness side.
      • Fig 6: Measuring Resistance
      GF0043888Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : INSTALL a new steering wheel rotation sensor. REFER to Steering Wheel Rotation Sensor . CALIBRATE the ABS module. FOLLOW the scan tool directions for the calibration procedure. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
    2. NO  : REPAIR the affected circuit(s). CALIBRATE the ABS module. FOLLOW the scan tool directions for the calibration procedure. CLEAR the DTCs. REPEAT the self-test.
scientia non olet · About LEMON Manuals