VEHICLE STABILITY CONTROL 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

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 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.

A017EH6E01
DTC Code DTC Detection Condition Trouble Area

C1405

C1406

Either of the following is detected:


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

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

  • Front speed sensor 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

Refer to DTCs C1401 and C1402 Click here.

INSPECTION PROCEDURE

Note

When replacing the brake actuator assembly, perform zero point calibration 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 FR speed sensor open detection / ERROR or NORMAL

      ERROR: Momentary interruption

      NORMAL: Normal

      		 -
      FL Speed Open FL speed sensor open detection / ERROR or NORMAL

      ERROR: Momentary interruption

      NORMAL: Normal

      		 -
      OK
      There are no momentary interruptions.

      Tech Tips

      Perform the above inspection before removing the sensor and connector.


    NG

    CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - FRONT SPEED SENSOR) Click here

    OK

  2. READ VALUE ON INTELLIGENT TESTER (FRONT SPEED SENSOR)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine.

    4. Select the Data List mode on the intelligent tester Click here.

      ABS / VSC / TRC:
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Wheel Speed FR wheel speed sensor reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Actual wheel speed Similar speed as indicated on speedometer
      FL Wheel Speed FL wheel speed sensor reading /min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Actual wheel speed Similar speed as indicated on speedometer

    5. 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, see 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

    CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - FRONT SPEED SENSOR) 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 recorded Click here.

      Result
      Result Proceed to
      DTCs (C1405 and C1406) are not output A
      DTCs (C1405 and/or C1406) are output B

      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.


    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Click here

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


    1. A017ESEE08

      Turn the ignition switch off.

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

    3. Disconnect the skid control ECU connector and the front 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
      A24-7 (FR+) - A25-2 (FR+) Always Below 1 Ω
      A24-7 (FR+) - Body ground Always 10 kΩ or higher
      A24-6 (FR-) - A25-1 (FR-) Always Below 1 Ω
      A24-6 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A24-19 (FL+) - A14-2 (FL+) Always Below 1 Ω
      A24-19 (FL+) - Body ground Always 10 kΩ or higher
      A24-18 (FL-) - A14-1 (FL-) Always Below 1 Ω
      A24-18 (FL-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT SKID CONTROL ECU (SENSOR INPUT)


    1. A017BKWE14

      Reconnect the skid control ECU connector.

    2. Turn the ignition switch on (IG).

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

      Standard voltage
      for RH
      Tester Connection Switch Condition Specified Condition
      A25-2 (FR+) - Body ground Ignition switch on (IG) 8 to 14 V
      for LH
      Tester Connection Switch Condition Specified Condition
      A14-2 (FL+) - Body ground Ignition switch on (IG) 8 to 14 V

      Note

      Check the speed sensor signal after replacement Click here.

      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.


    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

    REPLACE FRONT SPEED SENSOR Click here