ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C1405, C1406

DTC Code DTC Name
C1405 Open or Short in Front Speed Sensor RH Circuit
C1406 Open or Short in Front Speed Sensor LH Circuit

DESCRIPTION

Refer to DTCs C1401 and C1402 Click here.

DTC Code DTC Detection Condition Trouble Area

C1405

C1406

Either condition is met:


  1. An open in the speed sensor signal circuit continues for 0.5 seconds or more.

  2. With the IG1 terminal voltage at 9.5 V or higher, the sensor power supply voltage decreases for 0.5 seconds or more.

  • Front speed sensor RH/LH

  • Front skid control sensor wire RH/LH

  • Speed sensor circuit

  • Brake actuator assembly (Skid control ECU)

Tech Tips


  • DTC C1405 is for the front speed sensor RH.

  • DTC C1406 is for the front speed sensor LH.

WIRING DIAGRAM

B001F86E66

CAUTION / NOTICE / HINT

Note


  • When replacing the brake actuator assembly, perform calibration Click here.

  • Check the speed sensor signal after replacement Click here.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)


    1. Using the intelligent tester, check for any momentary interruption in the wire harness and connector corresponding to the DTC Click here.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Speed Open Front speed sensor RH open circuit detection/ Error or Normal Normal -
      FL Speed Open Front speed sensor LH open circuit detection/ Error or Normal Normal -
      OK
      Normal (there are no momentary interruptions).

      Tech Tips

      Perform the above inspection before removing the sensor and disconnecting the connector.


    NG

    INSPECT SKID CONTROL SENSOR WIRE Click here

    OK

  2. READ VALUE USING INTELLIGENT TESTER (FR/FL WHEEL SPEED)


    1. Turn the ignition switch off

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine.

    4. Turn the intelligent tester on.

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

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Wheel Speed Front speed sensor RH value/ min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Actual wheel speed No large fluctuations when driving at a constant speed.
      FL Wheel Speed Front speed sensor LH value/ min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Actual wheel speed No large fluctuations when driving at a constant speed.

    6. Check that there is no difference between the speed value output from the speed sensor displayed on the intelligent tester 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, refer to the reference chart Click here.

      OK
      The speed value output from the speed sensor displayed on the intelligent tester is the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).

    NG

    INSPECT SKID CONTROL SENSOR WIRE Click here

    OK

  3. RECONFIRM DTC


    1. Turn the ignition switch off.

    2. Clear the DTCs Click here.

    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
      DTC is not output A
      DTC is output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  4. INSPECT SKID CONTROL SENSOR WIRE


    1. Turn the ignition switch off.

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

    3. Remove the skid control sensor wire Click here.

    4. B001DNTE05
      Text in Illustration
      *A for RH
      *B for LH
      *1 Skid Control Sensor Wire

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      Ap1-1 - p1-1 (FR-) Always Below 1 Ω
      Ap1-2 - p1-2 (FR+) Always Below 1 Ω
      Ap1-1 - Ap1-2 Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      Ap2-1 - p2-1 (FL-) Always Below 1 Ω
      Ap2-2 - p2-2 (FL+) Always Below 1 Ω
      Ap2-1 - Ap2-2 Always 10 kΩ or higher

    NG

    REPLACE SKID CONTROL SENSOR WIRE Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - FRONT SPEED SENSOR)


    1. Install the skid control sensor wire.

    2. Disconnect the A6 skid control ECU connector.

    3. Disconnect the p1 and/or p2 speed sensor connector.

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      A6-7 (FR+) - p1-2 (FR+) Always Below 1 Ω
      A6-7 (FR+) - Body ground Always 10 kΩ or higher
      A6-6 (FR-) - p1-1 (FR-) Always Below 1 Ω
      A6-6 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A6-19 (FL+) - p2-2 (FL+) Always Below 1 Ω
      A6-19 (FL+) - Body ground Always 10 kΩ or higher
      A6-18 (FL-) - p2-1 (FL-) Always Below 1 Ω
      A6-18 (FL-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK TERMINAL VOLTAGE (FR+, FL+)


    1. Connect the A6 skid control ECU connector.

    2. Disconnect the p1 and/or p2 speed sensor connector.

    3. B001H4OE02
      Text in Illustration
      *A for RH
      *B for LH
      *a

      Front view of wire harness connector

      (to Front Speed Sensor)

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

      Standard Voltage
      for RH
      Tester Connection Switch Condition Specified Condition
      p1-2 (FR+) - Body ground Ignition switch ON 8 to 14 V
      for LH
      Tester Connection Switch Condition Specified Condition
      p2-2 (FL+) - Body ground Ignition switch ON 8 to 14 V

    OK

    REPLACE FRONT SPEED SENSOR Click here

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here