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

Each speed sensor detects wheel speed and sends signals to the skid control ECU (brake actuator assembly). These signals are used by the ABS control system.

The speed sensor rotors have 48 serrations. Hall IC type speed sensors use the frequency of output pulses to detect the vehicle speed. Because the sensor outputs digital pulses, it can detect the vehicle speed even when the vehicle is nearly stationary.

A01W04YE38

Tech Tips

Check the connection status between the sensor connector and the vehicle wire harness.

DTC No. DTC Detection Condition Trouble Area

C1401

C1402

Any of the following is detected:


  1. At a vehicle speed of 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.

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

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

  • Front speed sensor RH/LH

  • Sensor installation

  • Front speed sensor rotor RH/LH (front drive outboard joint shaft assembly RH/LH)

Tech Tips


  • DTC C1401 is for the front speed sensor RH.

  • DTC C1402 is for the front speed sensor LH.

WIRING DIAGRAM

A01W2R4E81
*a Front Speed Sensor RH
*b Front Speed Sensor LH
*c Skid Control ECU (Brake Actuator Assembly)

PROCEDURE


  1. CHECK FRONT SPEED SENSOR INSTALLATION


    1. A01W0XHE22
      Text in Illustration
      *1 Front Speed Sensor
      *a Correct
      *b Incorrect
      *c 8.5 N*m
      *d No clearance

      Check the speed sensor installation.

      OK
      There is no clearance between the sensor and the front steering knuckle.
      The installation bolt is tightened properly.
      Torque
      8.5 N*m (87 kgf*cm, 75 in.*lbf)

    NG

    INSTALL FRONT SPEED SENSOR CORRECTLY Click here

    OK

  2. INSPECT FRONT SPEED SENSOR AND SENSOR ROTOR


    1. Remove the front speed sensor and the component with the sensor rotor (See page for speed sensor, and for sensor rotor (for 2GR-FE), Click here for sensor rotor (for 2AR-FE, 6AR-FSE)).

    2. Check the speed sensor tip and speed sensor rotor.

      OK
      No scratches, oil, or foreign matter on the sensor tip and rotor.

      Note


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

        If there are any ferrous metal filings stuck to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign matter before replacing the sensor.

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


    NG

    CLEAN OR REPLACE FRONT SPEED SENSOR OR COMPONENT WITH SENSOR ROTOR

    OK

  3. READ VALUE USING GTS (FRONT SPEED SENSOR)


    1. Install the front speed sensor and the component with the sensor rotor.

    2. Connect the GTS to the DLC3.

    3. Start the engine.

    4. Select the Data List using the GTS Click here.

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

    5. 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 pressure, 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 similar to the speed indicated on the speedometer.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  4. 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

  5. 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 40 km/h (25 mph) or more for at least 60 seconds.

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

      Result
      Result Proceed to
      DTCs C1401 and C1402 are not output. A
      DTCs C1401 and/or C1402 are output (for 2GR-FE). B
      DTCs C1401 and/or C1402 are output (for 2AR-FE, 6AR-FSE). C

      Note

      Check the speed sensor signal after replacement Click here.

      Tech Tips


      • If the front speed sensor rotor needs to be replaced, replace the front drive outboard joint shaft assembly.

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


    A

    END

    B

    REPLACE FRONT DRIVE OUTBOARD JOINT SHAFT ASSEMBLY Click here

    C

    REPLACE FRONT DRIVE OUTBOARD JOINT SHAFT ASSEMBLY Click here