ANTI-LOCK BRAKE SYSTEM(for Type B), 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 C1413 and C1414.

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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 conditions 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

  • Speed sensor circuit

  • Skid control ECU (Brake actuator assembly)

C1406

Open or Short in Front Speed Sensor LH Circuit

Either of the following conditions 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 LH

  • Speed sensor circuit

  • Skid control ECU (Brake actuator assembly)
Tip:

Even after the trouble areas are repaired, the ABS warning light will not go off unless the following operations are performed:

  1. Drive the vehicle at 20 km/h (12 mph) for 30 seconds or more and check that the ABS warning light goes off.

  2. Clear the DTCs.

Tip:

  • DTC C1405 is for the front speed sensor RH.

  • DTC C1406 is for the front speed sensor LH.

WIRING DIAGRAM

Refer to DTCs C1413 and C1414.

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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 a DTC.

      Click here

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      FR Speed Sensor Voltage Open

      Front speed sensor RH voltage open detection

      Error or Normal

      Error: Momentary interruption

      Normal: Normal

      -

      FL Speed Sensor Voltage Open

      Front speed sensor LH voltage open detection

      Error or Normal

      Error: Momentary interruption

      Normal: Normal

      -

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      FR Speed Sensor Voltage Open

      FL Speed Sensor Voltage Open

      OK

      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. 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

    5. Check the speed value output from the speed sensor displayed on the GTS.

      Tip:

      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 hereClick here

      OK

      The speed value output from the speed sensor displayed on the GTS is similar to the speed indicated on the speedometer.

    Result

    Proceed to

    OK

    NG
    NG

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

    OK

  3. RECONFIRM DTC

    1. Turn the ignition switch off.

    2. Clear the DTCs.

      Click here

      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the ignition switch off.

    4. Start the engine.

    5. Perform a road test.

    6. Check if the same DTC is output.

      Click here

      Chassis > ABS/VSC/TRC > Trouble Codes

      Result

      Result

      Proceed to

      DTCs C1405 and C1406 are not output.

      A

      DTCs C1405 and/or C1406 are output.

      B
      Tip:

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

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    A

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick 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 A124 skid control ECU (brake actuator assembly) connector.

    4. Disconnect A157 or A158 front speed sensor connector.

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

      Standard Resistance

      Table 1. for RH

      Tester Connection

      Condition

      Specified Condition

      A124-7 (FR+) - A157-1 (FR+)

      Always

      Below 1 Ω

      A124-7 (FR+) or A157-1 (FR+) - Body ground

      Always

      10 kΩ or higher

      A124-6 (FR-) - A157-2 (FR-)

      Always

      Below 1 Ω

      A124-6 (FR-) or A157-2 (FR-) - Body ground

      Always

      10 kΩ or higher
      Table 2. for LH

      Tester Connection

      Condition

      Specified Condition

      A124-19 (FL+) - A158-1 (FL+)

      Always

      Below 1 Ω

      A124-19 (FL+) or A158-1 (FL+) - Body ground

      Always

      10 kΩ or higher

      A124-18 (FL-) - A158-2 (FL-)

      Always

      Below 1 Ω

      A124-18 (FL-) or A158-2 (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. C156480C26

      *a

      Front view of wire harness connector

      (to Front Speed Sensor)

      Reconnect the A124 skid control ECU (brake actuator assembly) connector.

    2. 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

      Condition

      Specified Condition

      A157-1 (FR+) - Body ground

      Ignition switch ON

      5.7 to 14 V
      Table 4. for LH

      Tester Connection

      Condition

      Specified Condition

      A158-1 (FL+) - Body ground

      Ignition switch ON

      5.7 to 14 V
      Note:

      Check the speed sensor signal after replacement.

      Click here

      Tip:

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

      Click here

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE FRONT SPEED SENSOR

    Click here

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick here