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 48 serrations. The Hall IC type speed sensor uses the frequency of output pulses to detect the vehicle speed. Because the sensor outputs digital pulses, it can detect vehicle speeds even when the vehicle is nearly stationary.

Tech Tips

The output voltage values shown below are those when the skid control ECU and the speed sensors are connected to the vehicle harness.

A019M9UE01
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 and store system information 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 USING INTELLIGENT TESTER (FRONT SPEED SENSOR)


    1. Turn the engine switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine.

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

      ABS/VSC/TRC
      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

    5. Check that the speed value output from the speed sensor displayed on the intelligent tester.

      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 similar speed as indicated on the speedometer.

    NG

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

    OK

  3. RECONFIRM DTC


    1. Turn the engine 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 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 Click here

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


    1. A019MH2E19
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)
      *2

      Front view of wire harness connector

      (to Front Speed Sensor)

      Turn the engine 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
      A44-7 (FR+) - A37-2 (FR+) Always Below 1 Ω
      A44-7 (FR+) - Body ground Always 10 kΩ or higher
      A44-6 (FR-) - A37-1 (FR-) Always Below 1 Ω
      A44-6 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A44-19 (FL+) - A36-2 (FL+) Always Below 1 Ω
      A44-19 (FL+) - Body ground Always 10 kΩ or higher
      A44-18 (FL-) - A36-1 (FL-) Always Below 1 Ω
      A44-18 (FL-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT SKID CONTROL ECU (SENSOR INPUT)


    1. A019LSLE30
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Front Speed Sensor)

      Reconnect the skid control ECU connector.

    2. Turn the engine 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
      A37-2 (FR+) - Body ground Engine switch on (IG) 8 to 14 V
      for LH
      Tester Connection Switch Condition Specified Condition
      A36-2 (FL+) - Body ground Engine 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 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