VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1237/37, C1275/75, C1276/76, C1277/77, C1278/78

DTC Code DTC Name
C1237/37 Speed Sensor Rotor Faulty
C1275/75 Abnormal Change in Output Signal of Front Speed Sensor RH (Test Mode DTC)
C1276/76 Abnormal Change in Output Signal of Front Speed Sensor LH (Test Mode DTC)
C1277/77 Abnormal Change in Output Signal of Rear Speed Sensor RH (Test Mode DTC)
C1278/78 Abnormal Change in Output Signal of Rear Speed Sensor LH (Test Mode DTC)

DESCRIPTION

The skid control ECU measures the speed of each wheel by receiving signals from the speed sensor.

These signals are used for recognizing that all 4 wheels are operating properly.

Therefore, all wheel signals must be equal.

DTCs C1275/75 to C1278/78 can be deleted when the speed sensor sends a vehicle speed signal or the Test Mode ends. DTCs from C1275/75 to C1278/78 are output only in the Test Mode.

A0138FEE03
DTC Code DTC Detection Condition Trouble Area
C1237/37

When any of the following is detected:


  1. Discrepancy among four wheel speed sensor output.

  2. Abnormal pulse signals from 3 or more sensors.

  3. Continuous ABS control for 60 seconds or more.

  • Tire and wheel size

  • Tire deformation

  • Speed sensor rotor

  • Speed sensor

  • Speed sensor circuit

  • Brake actuator assembly (Skid control ECU)

C1275/75

C1276/76

C1277/77

C1278/78

 Detected only during Test Mode. Speed sensor rotor

Tech Tips


  • DTC C1275/75 is for the front speed sensor RH.

  • DTC C1276/76 is for the front speed sensor LH.

  • DTC C1277/77 is for the rear speed sensor RH.

  • DTC C1278/78 is for the rear speed sensor LH.

WIRING DIAGRAM

A0136SME02

INSPECTION PROCEDURE

Tech Tips

When C0200/31, C0205/32, C0210/33, C0215/34, C1330/35, C1331/36, C1332/38 and/or C1333/39 is output together with C1237/37, inspect and repair the trouble areas indicated by C0200/31, C0205/32, C0210/33, C0215/34, C1330/35, C1331/36, C1332/38 and/or C1333/39 first Click here for front, or Click here for rear).

PROCEDURE


  1. CHECK TIRES


    1. Check the size and condition of all 4 wheels Click here.

      Tech Tips

      The DTC is output when tire deformation or a difference in tire size is detected.

      OK
      The diameter of all 4 tires and air pressure are the same.

    NG

    REPLACE TIRES SO THAT ALL FOUR TIRES ARE THE SAME SIZE

    OK

  2. CHECK EACH SPEED SENSOR TIP


    1. Remove the each speed sensor Click here for front, or Click here for rear).

    2. Check the speed sensor tip.

      OK
      No scratches or foreign matter on the sensor tip.

      Note

      Check the speed sensor signal after cleaning or replacement Click here.


    NG

    CLEAN OR REPLACE EACH SPEED SENSOR

    OK

  3. CHECK EACH SPEED SENSOR ROTOR


    1. Remove each speed sensor rotor.

    2. Check the speed sensor rotors.

      OK
      No scratches, oil, or foreign matter on the rotors.

      Tech Tips


      • The front speed sensor rotor is incorporated into the front axle hub bearing.

      • The rear speed sensor rotor is incorporated into the rear axle hub and bearing assembly.

      Note

      Check the speed sensor signal after cleaning or replacement Click here.


    NG

    CLEAN OR REPLACE EACH SPEED SENSOR ROTOR

    OK

  4. INSPECT EACH SPEED SENSOR


    1. A0136E0E01

      Install the front speed sensor and speed sensor rotor.

    2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

    3. Disconnect each speed sensor connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      for RH
      Tester Connection Condition Specified Condition
      1 (FR+) - Body ground Always 10 kΩ or higher
      2 (FR-) - Body ground Always 10 kΩ or higher
      1 (RR+) - Body ground Always 10 kΩ or higher
      2 (RR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      1 (FL+) - Body ground Always 10 kΩ or higher
      2 (FL-) - Body ground Always 10 kΩ or higher
      1 (RL+) - Body ground Always 10 kΩ or higher
      2 (RL-) - Body ground Always 10 kΩ or higher

      Note

      Check the speed sensor signal after replacement Click here.


    NG

    REPLACE EACH SPEED SENSOR

    OK

  5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - EACH SPEED SENSOR)


    1. A0138HEE01

      Disconnect the skid control ECU connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      for RH
      Tester Connection Condition Specified Condition
      A41-9 (FR+) - A7-1 (FR+) Always Below 1 Ω
      A41-9 (FR+) - Body ground Always 10 kΩ or higher
      A41-10 (FR-) - A7-2 (FR-) Always Below 1 Ω
      A41-10 (FR-) - Body ground Always 10 kΩ or higher
      A41-8 (RR+) - H3-1 (RR+) Always Below 1 Ω
      A41-8 (RR+) - Body ground Always 10 kΩ or higher
      A41-29 (RR-) - H3-2 (RR-) Always Below 1 Ω
      A41-29 (RR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A41-26 (FL+) - A13-1 (FL+) Always Below 1 Ω
      A41-26 (FL+) - Body ground Always 10 kΩ or higher
      A41-5 (FL-) - A13-2 (FL-) Always Below 1 Ω
      A41-5 (FL-) - Body ground Always 10 kΩ or higher
      A41-6 (RL+) - H4-1 (RL+) Always Below 1 Ω
      A41-6 (RL+) - Body ground Always 10 kΩ or higher
      A41-27 (RL-) - H4-2 (RL-) Always Below 1 Ω
      A41-27 (RL-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. RECONFIRM DTC


    1. Turn the ignition switch to OFF.

    2. Reconnect the speed sensor connector.

    3. Clear the DTC Click here.

    4. Start the engine.

    5. Drive the vehicle at a speed of 20 km/h (12 mph) or more for at least 60 seconds.

    6. Check if the same DTC is recorded Click here.

      Result
      Result Proceed to
      DTC (C1237/37) output A
      DTC (C1237/37) not output B

    B

    CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Click here

    A

  7. REPLACE EACH SPEED SENSOR


    1. Turn the ignition switch to OFF.

    2. Replace each speed sensor Click here for front, or Click here for rear).

      Note

      Check the speed sensor signal after replacement Click here.


    NEXT

  8. RECONFIRM DTC


    1. Clear the DTC Click here.

    2. Start the engine.

    3. Drive the vehicle at a speed of 20 km/h (12 mph) or more for at least 60 seconds.

    4. Check if the same DTC is recorded Click here.

      Result
      Result Proceed to
      DTC (C1237/37) output A
      DTC (C1237/37) not output B

    B

    END

    A

  9. REPLACE EACH SPEED SENSOR ROTOR


    1. Replace each speed sensor rotor.

      Tech Tips


      • The front speed sensor rotor is incorporated into the front axle hub bearing.

      • The rear speed sensor rotor is incorporated into the rear axle hub and bearing assembly.

      Note

      Check the speed sensor signal after cleaning or replacement Click here.


    NEXT

  10. RECONFIRM DTC


    1. Clear the DTC Click here.

    2. Start the engine.

    3. Drive the vehicle at a speed of 20 km/h (12 mph) or more for at least 60 seconds.

    4. Check if the same DTC is recorded Click here.

      Result
      Result Proceed to
      DTC (C1237/37) output A
      DTC (C1237/37) not output B

    B

    END

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here