VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1401, C1402

DTC Code DTC Name
C1401 Front Speed Sensor RH Malfunction
C1402 Front Speed Sensor LH Malfunction

DESCRIPTION

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU (brake actuator assembly). These signals are used for the brake control.

Tech Tips

When the connectors between the speed sensor and skid control ECU (brake actuator assembly) are connected, the following waveform is output.

A01FEKJE01
DTC Code DTC Detection Condition Trouble Area

C1401

C1402

Any of the following is detected:


  1. At a vehicle speed 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors for 15 seconds or more (for 2WD) or for 30 seconds or more (for AWD).

  2. At a vehicle speed 10 km/h (6 mph) or more, output from one of the speed sensors is 0 km/h (0 mph) for 1 second or more.

  3. At a vehicle speed 10 km/h (6 mph) or more, outputs from both front speed sensors are 0 km/h (0 mph) for 15 seconds or more (for 2WD) or for 30 seconds or more (for AWD).

  • Front speed sensor

  • Speed sensor rotor

Tech Tips


  • DTC C1401 is for the front speed sensor RH.

  • DTC C1402 is for the front speed sensor LH.

WIRING DIAGRAM

A01FFMQE30
A01FH85E15

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK FRONT SPEED SENSOR INSTALLATION

    A01FISPE03
    Text in Illustration
    *A for 2WD
    *B for AWD
    *a No Clearance
    *b OK
    *c NG

    1. Check the speed sensor installation (for 2WD).

      OK
      There is no clearance between the sensor and the front axle hub.

    2. Check the speed sensor installation (for AWD).

      OK
      There is no clearance between the sensor and the front steering knuckle.
      The installation bolt is tightened properly.
      Result
      Result Proceed to
      OK (for AWD) A
      OK (for 2WD) B
      NG (for 2WD) C
      NG (for AWD) D

    B

    READ VALUE USING GTS (FR/FL WHEEL SPEED) Click here

    C

    REPLACE FRONT AXLE HUB SUB-ASSEMBLY Click here

    D

    INSTALL FRONT SPEED SENSOR CORRECTLY Click here

    A

  2. CHECK FRONT SPEED SENSOR TIP


    1. Remove the front speed sensor Click here.

    2. Check the speed sensor tip.

      OK
      No scratches, oil, 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.

      • 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 axle hub sub-assembly (front speed sensor rotor) Click here.

    2. Check the speed sensor rotor.

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

      Note

      Check the speed sensor signal after cleaning or replacement 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.


    NG

    CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR

    OK

  4. READ VALUE USING GTS (FR/FL WHEEL SPEED)


    1. Turn the engine switch off.

    2. Connect the GTS to the DLC3.

    3. Start the engine.

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Wheel Speed Front speed sensor RH reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Actual wheel speed No large fluctuations when driving at a constant speed.
      FL Wheel Speed Front speed sensor LH reading /min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Actual wheel speed No large fluctuations when driving at a constant speed.

    6. Check the speed value output from the speed sensor displayed on the GTS.

      Tech Tips

      Factors that affect the indicated vehicle speed include tire size, tire inflation, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart Click here.

      OK
      The speed value output from the speed sensor displayed on the GTS is the similar speed as indicated on the speedometer.
      Result
      Result Proceed to
      NG (for AWD) A
      NG (for 2WD) B
      OK C

      Note

      Check the speed sensor signal after replacement 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.

      • If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Click here.


    B

    REPLACE FRONT AXLE HUB SUB-ASSEMBLY Click here

    C

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  5. REPLACE FRONT SPEED SENSOR


    1. Turn the engine switch off.

    2. Replace the front speed sensor Click here.

      Note

      Check the speed sensor signal after replacement Click here.


    NEXT

  6. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Turn the engine switch off.

    3. Start the engine.

    4. Drive the vehicle at a speed of 10 km/h (6 mph) or more for at least 30 seconds.

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

      Result
      Result Proceed to
      DTCs (C1401 and C1402) are not output A
      DTCs (C1401 and/or C1402) are output B

      Note

      Check the speed sensor signal after replacement 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.

      • If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Click here.


    B

    REPLACE FRONT AXLE HUB SUB-ASSEMBLY Click here

    A

    END