ANTI-LOCK BRAKE SYSTEM(for Type B), Diagnostic DTC:C1271, C1272, C1275, C1276, C1413, C1414

DTC Code DTC Name
C1271 Low Output Signal of Front Speed Sensor RH (Test Mode DTC)
C1272 Low Output Signal of Front Speed Sensor LH (Test Mode DTC)
C1275 Abnormal Change in Output Signal of Front Speed Sensor RH (Test Mode DTC)
C1276 Abnormal Change in Output Signal of Front Speed Sensor LH (Test Mode DTC)
C1413 Front Speed Sensor RH Output Malfunction
C1414 Front Speed Sensor LH Output Malfunction

DESCRIPTION

Each speed sensor detects wheel speed and sends signals to the skid control ECU (brake actuator assembly). These signals are used by the ABS.

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

DTCs C1271, C1272, C1275 and C1276 are cleared when the speed sensor sends a vehicle speed signal or when Test Mode ends. DTCs C1271, C1272, C1275 and C1276 are output only in Test Mode.

A01TDQZE01

Tech Tips

Check the connection status between the sensor connector and the vehicle wire harness.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1271 Low Output Signal of Front Speed Sensor RH (Test Mode DTC) Detected only during Test Mode.
  • Front speed sensor RH

  • Sensor installation

  • Front speed sensor rotor RH (Front axle hub sub-assembly RH)

C1272 Low Output Signal of Front Speed Sensor LH (Test Mode DTC) Detected only during Test Mode.
  • Front speed sensor LH

  • Sensor installation

  • Front speed sensor rotor LH (Front axle hub sub-assembly LH)

C1275 Abnormal Change in Output Signal of Front Speed Sensor RH (Test Mode DTC) Detected only during Test Mode. Front speed sensor rotor RH (Front axle hub sub-assembly RH)
C1276 Abnormal Change in Output Signal of Front Speed Sensor LH (Test Mode DTC) Detected only during Test Mode. Front speed sensor rotor LH (Front axle hub sub-assembly LH)
C1413 Front Speed Sensor RH Output Malfunction

Any of the following conditions is detected:


  1. An open in the sensor signal circuit of a malfunctioning area occurs 255 times or more.

  2. At a vehicle speed of 20 km/h (12 mph) or more, noise occurs in the sensor signals of a malfunctioning wheel 75 times or more within 5 seconds.

  3. At a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per rotor rotation for 15 seconds or more.


  • Front speed sensor RH

  • Speed sensor circuit

  • Sensor installation

  • Front speed sensor rotor RH (Front axle hub sub-assembly RH)

  • Skid control ECU (Brake actuator assembly)

C1414 Front Speed Sensor LH Output Malfunction

Any of the following conditions is detected:


  1. An open in the sensor signal circuit of a malfunctioning area occurs 255 times or more.

  2. At a vehicle speed of 20 km/h (12 mph) or more, noise occurs in the sensor signals of a malfunctioning wheel 75 times or more within 5 seconds.

  3. At a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per rotor rotation for 15 seconds or more.


  • Front speed sensor LH

  • Speed sensor circuit

  • Sensor installation

  • Front speed sensor rotor LH (Front axle hub sub-assembly LH)

  • Skid control ECU (Brake actuator assembly)

Tech Tips

for C1413 and C1414: 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.

Tech Tips


  • DTC C1413 is for the front speed sensor RH.

  • DTC C1414 is for the front speed sensor LH.

WIRING DIAGRAM

A01TDNZE69
*a Front Speed Sensor RH
*b Front Speed Sensor LH
*c Skid Control ECU (Brake Actuator Assembly)

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 Open Front speed sensor RH open detection Error or Normal

      Error: Momentary interruption

      Normal: Normal

      -
      FL Speed Open Front speed sensor LH open detection Error or Normal

      Error: Momentary interruption

      Normal: Normal

      -

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      FR Speed Open
      FL Speed Open
      OK
      There are no momentary interruptions.

      Tech Tips

      Perform the above inspection before removing the sensor and connector.

      Result
      Proceed to
      OK
      NG

    NG
    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.

      Tech Tips

      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 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
    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 C1413 and C1414 are not output. A
      DTCs C1413 and/or C1414 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 before replacing parts.

      Click here


    A
    B
  4. CHECK FRONT SPEED SENSOR INSTALLATION


    1. A01TBUFC10
      *1 Front Speed Sensor
      *a Correct
      *b Incorrect
      *c 8.5 Nm
      *d No clearance

      Check the speed sensor installation.

      OK
      There is no clearance between the sensor and the front steering knuckle.
      The installation bolt is tightened properly.
      Torque
      8.5 N*m (87 kgf*cm, 75 in.*lbf)
      Result
      Proceed to
      OK
      NG

    NG
    OK
  5. CHECK FRONT SPEED SENSOR AND SENSOR ROTOR


    1. Remove the front speed sensor and the component with the sensor rotor.

      for speed sensor: Click here

      for sensor rotor: Click here

    2. Check the speed sensor tip and speed sensor rotor.

      OK
      No scratches, oil, or foreign matter on the sensor tip and rotor.

      Note


      • If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.

        If there are any ferrous metal filings stuck to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign matter before replacing the sensor.

      • Check the speed sensor signal after cleaning or replacement.

        Click here

      Result
      Proceed to
      OK
      NG

    NG
    OK
  6. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SPEED SENSOR)


    1. Install the front speed sensor and the component with the sensor rotor.

    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
      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
      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
    OK
  7. INSPECT BRAKE ACTUATOR ASSEMBLY (SENSOR INPUT)


    1. A01T8HAC26
      *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
      for RH
      Tester Connection Condition Specified Condition
      A157-1 (FR+) - Body ground Ignition switch ON 5.7 to 14 V
      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

      Tech Tips

      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
    NG