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 (brake actuator assembly). These signals are used for brake control.

Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn.

Each speed sensor detects that magnetic change and sends a pulse signal to the skid control ECU (brake actuator assembly).

Tech Tips

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

B005A6DC01
*1 Speed Sensor *2 Speed Sensor Rotor
*a

Waveform (Reference):

Between Speed Sensor (-) and Body Ground

 *b Low speed
*c High speed - -
DTC No. Detection Item DTC Detection Condition Trouble Area Note
C1401 Front Speed Sensor RH Malfunction

Either 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*1 or 30 seconds or more*2.

  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*1 or 30 seconds or more*2. (except both rear speed sensors are 0 km/h (0 mph))

  • Front speed sensor RH

  • Front speed sensor rotor RH (Front axle hub sub-assembly RH)

  • Sensor installation

 -
C1402 Front Speed Sensor LH Malfunction

Either 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*1 or 30 seconds or more*2.

  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*1 or 30 seconds or more*2. (except both rear speed sensors are 0 km/h (0 mph))

  • Front speed sensor LH

  • Front speed sensor rotor LH (Front axle hub sub-assembly LH)

  • Sensor installation

 -

WIRING DIAGRAM

B0059YEE07

PROCEDURE


  1. CHECK FRONT SPEED SENSOR INSTALLATION


    1. Turn the engine switch off.

    2. B0058BYC14
      *a Normal
      *b Abnormal
      *c Clearance

      Check the speed sensor installation.

      Click here

      OK
      There is no clearance between the sensor and the front steering knuckle.
      The installation bolt is tightened properly.
      Result
      Proceed to
      OK
      NG

    NG

    INSTALL FRONT SPEED SENSOR CORRECTLY Click here

    OK

  2. INSPECT 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.

      • 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

      Result
      Proceed to
      OK
      NG

    NG

    CLEAN OR REPLACE FRONT SPEED SENSOR

    OK

  3. INSPECT FRONT SPEED SENSOR ROTOR


    1. Remove the front axle hub sub-assembly.

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

    3. Reinstall the front speed sensor and the front axle hub assembly.

      Click here for the front speed sensor

      Click here for the front axle hub assembly

      Result
      Proceed to
      OK
      NG

    NG

    CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR

    OK

  4. READ VALUE USING GTS (FRONT SPEED SENSOR)


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Turn the GTS on.

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

    5. According to the display on the GTS, read the Data List.


      Chassis > ABS/VSC/TRC > Data List
      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.: 326.4 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.: 326.4 km/h (202 mph)

      		 Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      FR Wheel Speed
      FL Wheel Speed

    6. Check that there is no difference between the speed value output from the speed sensor displayed on the GTS and the speed value displayed on the speedometer when driving the vehicle.

      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 same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).

      Tech Tips

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

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  5. REPLACE FRONT SPEED SENSOR


    1. Turn the engine switch off.

    2. Replace the front speed sensor.

      Click here

      Note

      After replacing the speed sensor, perform a Test Mode (signal check) inspection sensor check.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    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 recorded.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Proceed to
      DTCs C1401 and C1402 are not output
      DTCs C1401 and/or C1402 are output

      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.


    DTCs C1401 and C1402 are not output

    END

    DTCs C1401 and/or C1402 are output

    REPLACE FRONT AXLE HUB SUB-ASSEMBLY Click here