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 sensors.

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

Therefore, all wheel signals must indicate the same speed.

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

A004TG2E29
DTC Code DTC Detection Condition Trouble Area
C1237/37

When any of the following is detected:


  1. Discrepancy among the four wheel speed sensor outputs.

  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 (Front axle hub sub-assembly or rear axle hub and bearing assembly)

  • Speed sensor circuit

  • Skid control ECU (Brake actuator assembly)

C1275/75

C1276/76

C1277/77

C1278/78

 Stored during Test Mode. Speed sensor rotor (Front axle hub sub-assembly or rear axle hub and bearing assembly)

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

A004P2GE20

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU (brake actuator assembly), perform the engine variant learning Click here.

Tech Tips

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

PROCEDURE


  1. CHECK TIRES


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

      Tech Tips

      DTC C1237/37 is stored when tire deformation or a difference in tire size is detected.

      OK
      The diameters of all 4 tires are the same.
      Result
      Result Proceed to
      OK for front speed sensor A
      for rear speed sensor B
      NG C

    B

    CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE) Click here

    C

    REPLACE TIRES SO THAT ALL FOUR TIRES ARE THE SAME SIZE

    A

  2. CHECK FRONT SPEED SENSOR TIP


    1. Remove the front speed sensor Click here.

    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 FRONT SPEED SENSOR

    OK

  3. CHECK FRONT SPEED SENSOR ROTOR


    1. Remove the front speed sensor rotor Click here.

      Tech Tips

      The front speed sensor rotor is incorporated into the front axle hub sub-assembly.

    2. Check the speed sensor rotors.

      Result
      Result Proceed to
      Scratches, oil or foreign matter on the rotors A
      No scratches, oil or foreign matter on the rotors B

      Note

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


    A

    CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR

    B

    CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - EACH SPEED SENSOR) Click here

  4. CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)


    1. A004NFXE02
      *1 Skid Control Sensor Wire:
      *2 Sensor Side Connector "A":
      *3 Vehicle Side Connector "B":

      Remove the skid control sensor wire Click here.

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      z2 ("A"-2) - z2 ("B"-1) Always Below 1 Ω
      z2 ("A"-2) - z2 ("B"-2) Always 10 kΩ or higher
      z2 ("A"-2) - Body ground Always 10 kΩ or higher
      z2 ("A"-1) - z2 ("B"-2) Always Below 1 Ω
      z2 ("A"-1) - z2 ("B"-1) Always 10 kΩ or higher
      z2 ("A"-1) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      z1 ("A"-2) - z1 ("B"-1) Always Below 1 Ω
      z1 ("A"-2) - z1 ("B"-2) Always 10 kΩ or higher
      z1 ("A"-2) - Body ground Always 10 kΩ or higher
      z1 ("A"-1) - z1 ("B"-2) Always Below 1 Ω
      z1 ("A"-1) - z1 ("B"-1) Always 10 kΩ or higher
      z1 ("A"-1) - Body ground Always 10 kΩ or higher

      Note

      Check the speed sensor signal after replacement Click here.


    NG

    REPLACE SKID CONTROL SENSOR WIRE Click here

    OK

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


    1. Disconnect the skid control ECU connector.

    2. Disconnect the front speed sensor connector and/or the rear speed sensor connector.

    3. A004RA1E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)
      *2

      Front view of wire harness connector

      (to Front Speed Sensor)
      *3

      Front view of wire harness connector

      (to Rear Speed Sensor)

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

      Standard Resistance
      for Front RH
      Tester Connection Condition Specified Condition
      A42-9 (FR+) - A23-1 (FR+) Always Below 1 Ω
      A42-9 (FR+) - Body ground Always 10 kΩ or higher
      A42-10 (FR-) - A23-2 (FR-) Always Below 1 Ω
      A42-10 (FR-) - Body ground Always 10 kΩ or higher
      for Front LH
      Tester Connection Condition Specified Condition
      A42-26 (FL+) - A24-1 (FL+) Always Below 1 Ω
      A42-26 (FL+) - Body ground Always 10 kΩ or higher
      A42-5 (FL-) - A24-2 (FL-) Always Below 1 Ω
      A42-5 (FL-) - Body ground Always 10 kΩ or higher
      for Rear RH
      Tester Connection Condition Specified Condition
      A42-8 (RR+) - z2-2 (RR+) Always Below 1 Ω
      A42-8 (RR+) - Body ground Always 10 kΩ or higher
      A42-29 (RR-) - z2-1 (RR-) Always Below 1 Ω
      A42-29 (RR-) - Body ground Always 10 kΩ or higher
      for Rear LH
      Tester Connection Condition Specified Condition
      A42-6 (RL+) - z1-2 (RL+) Always Below 1 Ω
      A42-6 (RL+) - Body ground Always 10 kΩ or higher
      A42-27 (RL-) - z1-1 (RL-) Always Below 1 Ω
      A42-27 (RL-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. PERFORM TEST MODE (SIGNAL CHECK)


    1. Perform the speed sensor signal check in "Test Mode Procedure" Click here.

      OK
      All Test Mode DTCs are cleared.
      Result
      Result Proceed to
      DTC(s) is not cleared. for front speed sensor A
      for rear speed sensor B
      DTCs are cleared. C

    B

    REPLACE REAR SPEED SENSOR AND REAR SPEED SENSOR ROTOR Click here

    C

    USE SIMULATION METHOD TO CHECK Click here

    A

  7. REPLACE FRONT SPEED SENSOR


    1. Turn the ignition switch off.

    2. Replace the front speed sensor Click here.

      Note

      Check the speed sensor signal after replacement Click here.


    NEXT

  8. RECONFIRM DTC


    1. Clear the DTCs 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 output Click here.

      Result
      Result Proceed to
      DTC C1237/37 is output. A
      DTC C1237/37 is not output. B

    B

    END

    A

  9. REPLACE FRONT SPEED SENSOR ROTOR


    1. Turn the ignition switch off.

    2. Replace the front axle hub sub-assembly (front speed sensor rotor) Click here.

      Tech Tips

      The front speed sensor rotor is incorporated into the front axle hub sub-assembly.

      If the front speed sensor rotor needs to be replaced, replace it together with the front axle hub sub-assembly.

      Note

      Check the speed sensor signal after replacement Click here.


    NEXT

  10. RECONFIRM DTC


    1. Clear the DTCs 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 output Click here.

      Result
      Result Proceed to
      DTC C1237/37 is output. A
      DTC C1237/37 is not output. B

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    B

    END

  11. REPLACE REAR SPEED SENSOR AND REAR SPEED SENSOR ROTOR


    1. Turn the ignition switch off.

    2. Replace the rear axle hub and bearing assembly (rear speed sensor and rear speed sensor rotor) Click here.

      Tech Tips

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

      Note

      Check the speed sensor signal after replacement Click here.


    NEXT

  12. RECONFIRM DTC


    1. Clear the DTCs 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 output Click here.

      Result
      Result Proceed to
      DTC C1237/37 is output. A
      DTC C1237/37 is not output. B

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    B

    END