ELECTRONICALLY CONTROLLED BRAKE SYSTEM(w/ Vacuum Brake Booster), Diagnostic DTC:C1401, C1402

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

DESCRIPTION

Refer to DTCs C1413 and C1414.

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DTC No. Detection Item DTC Detection Condition Trouble Area Note
C1401 Front Speed Sensor RH Malfunction

Any of the following is detected:


  • 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 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 30 seconds or more*1.

  • 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.

  • 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*2.

  • 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 30 seconds or more*1.

  • Sensor installation

  • Front speed sensor RH*1

  • Front speed sensor RH (front axle hub sub-assembly RH)*2

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

  • Front skid control sensor wire RH*2

  • Wire harness or connector

 -
C1402 Front Speed Sensor LH Malfunction

Any of the following is detected:


  • 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 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 30 seconds or more*1.

  • 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.

  • 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*2.

  • 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 30 seconds or more*1.

  • Sensor installation

  • Front speed sensor LH*1

  • Front speed sensor LH (front axle hub sub-assembly LH)*2

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

  • Front skid control sensor wire LH*2

  • Wire harness or connector

 -

C1401 DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2 Pattern 3 Pattern 4 Pattern 5
Diagnosis Condition - - - - - -
Malfunction Status 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*2 ○ - - - -
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*1 - ○ - - -
At a vehicle speed less than 10 km/h (6 mph), output from one of the speed sensors is 0 km/h (0 mph) - - ○ - -
At a vehicle speed of 10 km/h (6 mph) or more, outputs from both front speed sensors are 0 km/h (0 mph)*2 - - - ○ -
At a vehicle speed of 10 km/h (6 mph) or more, outputs from both front speed sensors are 0 km/h (0 mph)*1 - - - - ○
Detection Time 15 seconds or more. 30 seconds or more. 1 second or more. 15 seconds or more. 30 seconds or more.
Number of Trips 1 trip 1 trip 1 trip 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

C1402 DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2 Pattern 3 Pattern 4 Pattern 5
Diagnosis Condition - - - - - -
Malfunction Status 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*2 ○ - - - -
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*1 - ○ - - -
At a vehicle speed less than 10 km/h (6 mph), output from one of the speed sensors is 0 km/h (0 mph) - - ○ - -
At a vehicle speed of 10 km/h (6 mph) or more, outputs from both front speed sensors are 0 km/h (0 mph)*2 - - - ○ -
At a vehicle speed of 10 km/h (6 mph) or more, outputs from both front speed sensors are 0 km/h (0 mph)*1 - - - - ○
Detection Time 15 seconds or more. 30 seconds or more. 1 second or more. 15 seconds or more. 30 seconds or more.
Number of Trips 1 trip 1 trip 1 trip 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

WIRING DIAGRAM

Refer to DTCs C1413 and C1414.

Click here

PROCEDURE


  1. CHECK FRONT SPEED SENSOR INSTALLATION


    1. Turn the engine switch off.

    2. B006CAKC09
      *A for 2WD
      *B for AWD
      *a No clearance
      *b Correct
      *c Incorrect

      for 2WD:

      Check the speed sensor installation.

      Click here

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

      for AWD:

      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 (for 2WD)
      OK (for AWD)
      NG (for 2WD)
      NG (for AWD)

    OK (for AWD)

    CHECK FRONT SPEED SENSOR (CHECK FOR FOREIGN MATTER) Click here

    NG (for 2WD)

    REPLACE FRONT AXLE HUB SUB-ASSEMBLY Click here

    NG (for AWD)

    INSTALL FRONT SPEED SENSOR CORRECTLY Click here

    OK (for 2WD)

  2. READ VALUE USING GTS (FRONT SPEED SENSOR)


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Select the Data List using the GTS.

      Click here


      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 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

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

    4. 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.
      Result
      Result
      OK
      NG

      Tech Tips

      The front speed sensor rotor and front speed sensor are incorporated into the front axle hub sub-assembly.

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


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. INSPECT FRONT SKID CONTROL SENSOR WIRE

    B006DBCC07
    *A for RH
    *B for LH
    *1 Front Skid Control Sensor Wire
    *a

    Front view of wire harness connector

    (to Vehicle Side Connector)
    *b

    Front view of wire harness connector

    (to Sensor Side Connector)

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

    2. Disconnect the z21, A16, A25 and/or AA3 front skid control sensor wire connector.

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      z21 -1 (FR+) - A25 -5 (FR+) Always Below 1 Ω
      z21 -1 (FR+) or A25 -5 (FR+) - Body ground and other terminals Always 10 MΩ or higher
      z21 -2 (FR-) - A25 -1 (FR-) Always Below 1 Ω
      z21 -2 (FR-) or A25 -1 (FR-) - Body ground and other terminals Always 10 MΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A16 -2 (FL+) - AA3 -3 Always Below 1 Ω
      A16 -2 (FL+) or AA3 -3 - Body ground and other terminals Always 10 MΩ or higher
      A16 -1 (FL-) - AA3 -1 Always Below 1 Ω
      A16 -1 (FL-) or AA3 -1 - Body ground and other terminals Always 10 MΩ or higher

      Note

      Check the speed sensor signal after replacement.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FRONT SKID CONTROL SENSOR WIRE Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SKID CONTROL SENSOR WIRE)


    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the A9 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      A9-31 (FR+) - A25-5 (FR+) Always Below 1 Ω
      A9-31 (FR+) or A25-5 (FR+) - Body ground Always 10 kΩ or higher
      A9-30 (FR-) - A25-1 (FR-) Always Below 1 Ω
      A9-30 (FR-) or A25-1 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A9-18 (FL+) - AA3 -3 Always Below 1 Ω
      A9-18 (FL+) or AA3 -3 - Body ground Always 10 kΩ or higher
      A9-17 (FL-) - AA3 -1 Always Below 1 Ω
      A9-17 (FL-) or AA3 -1 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FRONT AXLE HUB SUB-ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. 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

  6. READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)


    1. Connect the Techstream to the DLC3.

    2. Start the engine.

    3. Select the Data List using the Techstream.

      Click here


      Chassis > ABS/VSC/TRAC > 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 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

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

    4. Check the speed value output from the speed sensor displayed on the Techstream.

      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 Techstream is similar to the speed indicated on the speedometer.
      Result
      Result
      OK
      NG

      Tech Tips

      The front speed sensor rotor and front speed sensor are incorporated into the front axle hub sub-assembly.

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


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  7. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SPEED SENSOR)


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

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

    3. Disconnect the A9 Skid control ECU (brake actuator assembly) connector.

    4. Disconnect the A72 or A73 front speed sensor connector.

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      A9-31 (FR+) - A73-5 (FR+) Always Below 1 Ω
      A9-31 (FR+) or A73-5 (FR+) - Body ground Always 10 MΩ or higher
      A9-30 (FR-) - A73-1 (FR-) Always Below 1 Ω
      A9-30 (FR-) or A73-1 (FR-) - Body ground Always 10 MΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A9-18 (FL+) - A72-3 (FL+) Always Below 1 Ω
      A9-18 (FL+) or A72-3 (FL+) - Body ground Always 10 MΩ or higher
      A9-17 (FL-) - A72-1 (FL-) Always Below 1 Ω
      A9-17 (FL-) or A72-1 (FL-) - Body ground Always 10 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Remove the component with the 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