VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1405 and 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.

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DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1405

Open or Short in Front Speed Sensor RH Circuit

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 +BS terminal voltage at 9.5 V or higher, the sensor power supply voltage decreases for 0.5 seconds or more.

  • Front speed sensor RH

  • Skid control ECU (Brake actuator assembly)

  • Wire harness or connector

C1406

Open or Short in Front Speed Sensor LH Circuit

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 +BS terminal voltage at 9.5 V or higher, the sensor power supply voltage decreases for 0.5 seconds or more.

  • Front speed sensor LH

  • Skid control ECU (Brake actuator assembly)

  • Wire harness or connector

WIRING DIAGRAM

C241007E50

CAUTION / NOTICE / HINT

Note:

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration.

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PROCEDURE

  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

    1. Using the GTS, check for any momentary interruption in the wire harness and connector corresponding to the DTC.

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    Chassis > ABS/VSC/TRC > Data List

    Tester Display

    Measurement Item

    Range

    Normal Condition

    Diagnostic Note

    FR Speed Open

    Front speed sensor RH open detection

    Normal or Error

    Normal

    Error: Momentary interruption

    FL Speed Open

    Front speed sensor LH open detection

    Normal or Error

    Normal

    Error: Momentary interruption

    Chassis > ABS/VSC/TRC > Data List

    Tester Display

    FR Speed Open

    FL Speed Open

    OK

    Normal (There are no momentary interruptions.)

    Tip:

    Perform the above inspection before removing the sensor and connector.

    Result

    Proceed to

    OK

    NG
    NG

    CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SPEED SENSOR)Click here

    OK

  2. READ VALUE USING GTS (FRONT SPEED SENSOR)

    1. Turn the ignition switch off.

    2. Connect the GTS to the DLC3.

    3. Start the engine.

    4. Turn the GTS on.

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

    6. According to the display on the GTS, read the Data List.

    7. Check that there is no difference between the speed value output from the speed sensor displayed on the GTS and the speed value displayed on the speedometer when driving the vehicle.

      Tip:

      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.

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      OK

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

      Tip:

      If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step.

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      Result

      Proceed to

      OK

      NG

    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.: 326.4 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.: 326.4 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
    NG

    CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SPEED SENSOR)Click here

    OK

  3. RECONFIRM DTC

    1. Clear the DTCs.

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    2. Turn the ignition switch off.

    3. Start the engine.

    4. Perform a road test.

    5. Check if the same DTC is recorded.

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    Chassis > ABS/VSC/TRC > Clear DTCs

    Chassis > ABS/VSC/TRC > Trouble Codes

    Result

    Proceed to

    DTCs C1405 and C1406 are not output

    DTCs C1405 and/or C1406 are output
    DTCs C1405 and C1406 are not output

    USE SIMULATION METHOD TO CHECK

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    DTCs C1405 and/or C1406 are output

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click here

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

    1. 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 A100 skid control ECU (brake actuator assembly) connector and the A14 and/or A43 front speed sensor connector.

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

      Standard Resistance

      Table 1. for RH

      Tester Connection

      Condition

      Specified Condition

      A100-31 (FR+) - A43-1 (FR+)

      Always

      Below 1 Ω

      A100-30 (FR-) - A43-2 (FR-)

      Always

      Below 1 Ω

      A100-31 (FR+) or A43-1 (FR+) - Body ground

      Always

      10 kΩ or higher

      A100-30 (FR-) or A43-2 (FR-) - Body ground

      Always

      10 kΩ or higher
      Table 2. for LH

      Tester Connection

      Condition

      Specified Condition

      A100-18 (FL+) - A14-1 (FL+)

      Always

      Below 1 Ω

      A100-17 (FL-) - A14-2 (FL-)

      Always

      Below 1 Ω

      A100-18 (FL+) or A14-1 (FL+) - Body ground

      Always

      10 kΩ or higher

      A100-17 (FL-) or A14-2 (FL-) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT BRAKE ACTUATOR ASSEMBLY (SENSOR INPUT)

    1. Reconnect the A100 skid control ECU (brake actuator assembly) connector.

    2. C271648C01

      *A

      for RH

      *B

      for LH

      *a

      Front view of wire harness connector

      (to Front Speed Sensor)

      Turn the ignition switch to ON.

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

      Standard Voltage

      Table 3. for RH

      Tester Connection

      Switch Condition

      Specified Condition

      A43-1 (FR+) - Body ground

      Ignition switch ON

      8 to 14 V
      Table 4. for LH

      Tester Connection

      Switch Condition

      Specified Condition

      A14-1 (FL+) - Body ground

      Ignition switch ON

      8 to 14 V

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE FRONT SPEED SENSOR

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    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click here