ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C1337/37

DTC Code DTC Name
C1337/37 Diameter of the Tire is not Uniform

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 be equal.

DTC No. DTC Detection Condition Trouble Area
C1337/37 With the vehicle speed 20 km/h (12 mph) or higher, an average vehicle speed difference between the front and rear wheels continuously exceeding 20% for 20 seconds is detected 3 times consecutively.

  • Tire size

  • Speed sensor

  • Skid control rotor

  • Sensor installation

  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

Front speed sensor circuit: Refer to DTCs C0200/31, C0205/32, C1235/35 and C1236/36 Click here.

Rear speed sensor circuit: Refer to DTCs C0210/33, C0215/34, C1238/38 and C1239/39 Click here.

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK TIRE SIZE


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


    NG

    REPLACE TIRES SO THAT ALL 4 TIRES ARE SAME IN SIZE

    OK

  2. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - SPEED SENSOR)


    1. Turn the ignition switch off.

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

    3. Disconnect the B19 skid control ECU (brake actuator assembly) connector and the B18, B20 and/or P1 speed sensor connector.

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

      Standard Resistance
      for Front RH
      Tester Connection Condition Specified Condition
      B19-31 (FR+) - B18-2 Always Below 1 Ω
      B19-31 (FR+) or B18-2 - Body ground Always 10 kΩ or higher
      B19-30 (FR-) - B18-1 Always Below 1 Ω
      B19-30 (FR-) or B18-1 - Body ground Always 10 kΩ or higher
      for Front LH
      Tester Connection Condition Specified Condition
      B19-9 (FL+) - B20-2 Always Below 1 Ω
      B19-9 (FL+) or B20-2 - Body ground Always 10 kΩ or higher
      B19-8 (FL-) - B20-1 Always Below 1 Ω
      B19-8 (FL-) or B20-1 - Body ground Always 10 kΩ or higher
      for Rear RH
      Tester Connection Condition Specified Condition
      B19-33 (RR+) - P1-4 (RR+) Always Below 1 Ω
      B19-33 (RR+) or P1-4 (RR+) - Body ground Always 10 kΩ or higher
      B19-34 (RR-) - P1-3 (RR-) Always Below 1 Ω
      B19-34 (RR-) or P1-3 (RR-) - Body ground Always 10 kΩ or higher
      for Rear LH
      Tester Connection Condition Specified Condition
      B19-11 (RL+) - P1-2 (RL+) Always Below 1 Ω
      B19-11 (RL+) or P1-2 (RL+) - Body ground Always 10 kΩ or higher
      B19-12 (RL-) - P1-1 (RL-) Always Below 1 Ω
      B19-12 (RL-) or P1-1 (RL-) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for Rear LH) A
      OK (for Front RH, Front LH or Rear RH) B
      NG C

    B

    INSPECT BRAKE ACTUATOR ASSEMBLY Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

  3. INSPECT REAR SPEED SENSOR RH


    1. A003DV6E01
      Text in Illustration
      *1 Rear Speed Sensor RH
      *a

      Front view of wire harness connector

      (to Sensor Side Connector)
      *b

      Front view of wire harness connector

      (to Vehicle Side Connector)

      Turn the ignition switch off.

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

    3. Disconnect the A rear speed sensor RH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-3 - P1-1 (RL-) Always Below 1 Ω
      A-3 or P1-1 (RL-) - Body ground Always 10 kΩ or higher
      A-1 - P1-2 (RL+) Always Below 1 Ω
      A-1 or P1-2 (RL+) - Body ground Always 10 kΩ or higher

      Note

      Check the speed sensor signal after replacement Click here.


    NG

    REPLACE REAR SPEED SENSOR RH Click here

    OK

  4. INSPECT BRAKE ACTUATOR ASSEMBLY


    1. A003EZNE01
      Text in Illustration
      *A for Front RH
      *B for Front LH
      *a

      Front view of wire harness connector

      (to Front Speed Sensor)
      *b

      Front view of wire harness connector

      (to Rear Speed Sensor RH)

      Reconnect the B19 skid control ECU (brake actuator assembly) connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      for Front RH
      Tester Connection Switch Condition Specified Condition
      B18-2 - Body ground Ignition switch ON 5.7 to 14 V
      for Front LH
      Tester Connection Switch Condition Specified Condition
      B20-2 - Body ground Ignition switch ON 5.7 to 14 V
      for Rear RH
      Tester Connection Switch Condition Specified Condition
      P1-4 (RR+) - Body ground Ignition switch ON 5.7 to 14 V
      for Rear LH
      Tester Connection Switch Condition Specified Condition
      P1-2 (RL+) - Body ground Ignition switch ON 5.7 to 14 V

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY

    OK

  5. RECONFIRM DTC


    1. Disconnect the B18, B20 and/or P1 speed sensor connector.

    2. Clear the DTCs Click here.

    3. Drive the vehicle at a speed of approximately 30 km/h (19 mph) or more for 60 seconds or more.

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

      Result
      Result Proceed to
      DTC is not output A
      DTC is output B

    B

    INSPECT SPEED SENSOR TIP Click here

    A

    USE SIMULATION METHOD TO CHECK Click here

  6. INSPECT SPEED SENSOR TIP


    1. Remove the front speed sensor Click here.

    2. Remove the rear speed sensor Click here.

    3. Check the sensor tip.

      OK
      No scratches or foreign matter on the sensor tip.

      Note


      • If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.

      • If there is iron powder sticking to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign material before replacing the sensor.

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


    NG

    CLEAN OR REPLACE SPEED SENSOR

    OK

    CLEAN OR REPLACE SKID CONTROL ROTOR