ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1401, C1402

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

DESCRIPTION

Refer to DTCs C1413 and C1414.

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DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C1401 Malfunction in Front Speed Sensor RH Circuit

501

502

507

  • INF Code: 501


    • 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.

  • INF Code: 502


    • 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. (except when both rear speed sensors are 0 km/h (0 mph)).

  • INF Code: 507


    • At a vehicle speed of 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.

  • Front speed sensor RH

  • Speed sensor installed improperly

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

 ABS DTC
C1402 Malfunction in Front Speed Sensor LH Circuit

511

512

517

  • INF Code: 511


    • 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.

  • INF Code: 512


    • 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. (except when both rear speed sensors are 0 km/h (0 mph)).

  • INF Code: 517


    • At a vehicle speed of 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.

  • Front speed sensor LH

  • Speed sensor installed improperly

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

 ABS DTC

WIRING DIAGRAM

Refer to DTCs C1413 and C1414.

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PROCEDURE


  1. CHECK FRONT SPEED SENSOR INSTALLATION


    1. A001OK3C29
      *1 Front Speed Sensor
      *a OK
      *b NG
      *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)
      Result
      Proceed to
      OK
      NG

    NG

    REINSTALL OR REPLACE FRONT SPEED SENSOR Click here

    OK

  2. CHECK FRONT SPEED SENSOR (CHECK FOR FOREIGN MATTER)


    1. Remove the front speed sensor.

      Click here

    2. Check the front speed sensor tip.

      OK
      The sensor tip is free of scratches, oil, and foreign matter.

      Note


      • If there is oil or foreign matter on the speed sensor, clean the speed sensor.

      • If the speed sensor is damaged, replace the speed sensor with a new one.

      • 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. READ VALUE USING GTS (FRONT SPEED SENSOR)


    1. Install the front speed sensor.

    2. Select the Data List on the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      FR Wheel Speed Front speed sensor RH Min.: 0 km/h (0 mph), Max.: 326.4 km/h (203 mph) Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations
      FL Wheel Speed Front speed sensor LH Min.: 0 km/h (0 mph), Max.: 326.4 km/h (203 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

    3. Check the speed sensor output value.

      OK
      The output value changes in accordance with the vehicle speed.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  4. CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - FRONT SPEED SENSOR)


    1. Turn the power switch off.

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

      OK
      The connector is securely connected.

    3. Disconnect the A39 skid control ECU (brake booster with master cylinder assembly) connector.

    4. Disconnect the A25 or A13 front speed sensor connector.

    5. Check both the connector case and the terminals for deformation and corrosion.

      OK
      No deformation or corrosion.

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      A39-3 (FR+) - A25-1 (FR+) Always Below 1 Ω
      A39-3 (FR+) or A25-1 (FR+) - Body ground Always 10 kΩ or higher
      A39-4 (FR-) - A25-2 (FR-) Always Below 1 Ω
      A39-4 (FR-) or A25-2 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A39-31 (FL+) - A13-1 (FL+) Always Below 1 Ω
      A39-31 (FL+) or A13-1 (FL+) - Body ground Always 10 kΩ or higher
      A39-32 (FL-) - A13-2 (FL-) Always Below 1 Ω
      A39-32 (FL-) or A13-2 (FL-) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK FRONT SPEED SENSOR ROTOR (CHECK FOR FOREIGN MATTER)


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

      for Speed Sensor: Click here

      for Speed Sensor Rotor: Click here

    2. Check the speed sensor rotor.

      OK
      The rotor is free of scratches, oil, and foreign matter.

      Note


      • If there is oil or foreign matter on the speed sensor rotor, clean the speed sensor rotor.

      • If the speed sensor rotor is damaged, replace the speed sensor rotor with a new one.

      • 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.

      Result
      Result Proceed to
      OK A
      NG (The speed sensor rotor is damaged.) B
      NG (There is foreign matter on the speed sensor rotor.) C

    A

    REPLACE FRONT SPEED SENSOR Click here

    B

    REPLACE FRONT AXLE HUB SUB-ASSEMBLY Click here

    C

    CLEAN FRONT SPEED SENSOR ROTOR