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 wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for ABS control.

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

Tech Tips

The output voltage values shown below are those when the skid control ECU and the speed sensors are connected to the vehicle harness.

A019M9UE01
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 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 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 RH/LH

  • 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

A019MHIE21

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK FRONT SPEED SENSOR INSTALLATION


    1. A019MP4E26

      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. 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

      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 for 2GR-FE, or Click here for 1AR-FE).

    2. Check the speed sensor rotor.

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

      Note

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

      Tech Tips

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


    NG

    CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR

    OK

  4. READ VALUE USING INTELLIGENT TESTER (FRONT SPEED SENSOR)


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

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine.

    4. Select the Data List on the intelligent tester 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 that the speed value output from the speed sensor displayed on the intelligent tester.

      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 intelligent tester is the similar speed as indicated on the speedometer.

    NG

    REPLACE FRONT SPEED SENSOR Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

  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. Start the engine.

    3. Drive the vehicle at a speed of 40 km/h (25 mph) or more for at least 60 seconds.

    4. 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


      • If the front speed sensor rotor needs to be replaced, replace it together with 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 Click here.


    B

    REPLACE FRONT SPEED SENSOR ROTOR

    A

    END