ANTI-LOCK BRAKE SYSTEM(for Type A), Diagnostic DTC:C1237, C1275, C1276, C1277, C1278

DTC Code DTC Name
C1237 Speed Sensor Rotor Faulty
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)
C1277 Abnormal Change in Output Signal of Rear Speed Sensor RH (Test Mode DTC)
C1278 Abnormal Change in Output Signal of Rear Speed Sensor LH (Test Mode DTC)

DESCRIPTION

The skid control ECU (brake actuator assembly) measures the speed of each wheel by receiving signals from each speed sensor.

These signals are used for recognizing that all four wheels are operating properly.

Therefore, signals from all wheels must be equal.

DTCs C1275 to C1278 are cleared when the speed sensor sends a vehicle speed signal or when Test Mode ends. DTCs C1275 to C1278 are output only in Test Mode.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1237 Speed Sensor Rotor Faulty

Any of the following is detected:


  1. Discrepancy among four wheel speed sensor output.

  2. Abnormal pulse signals from 3 or more sensors.

  3. Continuous ABS control is performed for 60 seconds or more.

  • Tire and wheel size

  • Tire deformation

  • Speed sensor rotor

  • Speed sensor

  • Speed sensor circuit

  • Skid control ECU (brake actuator assembly)
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 drive outboard joint shaft 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 drive outboard joint shaft assembly LH)
C1277 Abnormal Change in Output Signal of Rear Speed Sensor RH (Test Mode DTC) Detected only during Test Mode. Rear speed sensor rotor RH (rear axle hub and bearing assembly RH)
C1278 Abnormal Change in Output Signal of Rear Speed Sensor LH (Test Mode DTC) Detected only during Test Mode. Rear speed sensor rotor LH (rear axle hub and bearing assembly LH)

Tech Tips


  • DTC C1275 is for the front speed sensor RH.

  • DTC C1276 is for the front speed sensor LH.

  • DTC C1277 is for the rear speed sensor RH.

  • DTC C1278 is for the rear speed sensor LH.

WIRING DIAGRAM

Refer to DTCs C1330, C1331, C1332, C1333, C1464, C1465, C1466 and C1467.

for front: Click here

for rear: Click here

CAUTION / NOTICE / HINT

Tech Tips

When C1330, C1331, C1332, C1333, C1464, C1465, C1466 and/or C1467 is output together with C1237, inspect and repair the trouble areas indicated by C1330, C1331, C1332, C1333, C1464, C1465, C1466 and/or C1467 first.

for C1330, C1331, C1464 and C1465: Click here

for C1332, C1333, C1466 and C1467: Click here

PROCEDURE


  1. CHECK TIRES


    1. Check the size and condition of all four tires.

      Click here

      Tech Tips

      The DTC is output when tire deformation or a difference in tire size is detected.

      OK
      The diameter of all four tires and the tire pressure are the same.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE TIRES SO THAT ALL FOUR TIRES ARE THE SAME SIZE

    OK

  2. READ VALUE USING GTS (SPEED SENSOR)


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. 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
      RR Wheel Speed Rear 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
      RL Wheel Speed Rear 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
      RR Wheel Speed
      RL Wheel Speed

    4. 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
      Result Proceed to
      OK A
      NG (for front) B
      NG (for rear) C

    B

    CHECK FRONT SPEED SENSOR AND SENSOR ROTOR Click here

    C

    INSPECT SKID CONTROL SENSOR Click here

    A

  3. PERFORM TEST MODE INSPECTION (SIGNAL CHECK)


    1. Turn the ignition switch off.

    2. Perform the sensor check using Test Mode Procedure.

      Click here


      Chassis > ABS/VSC/TRC > Utility
      Tester Display
      Signal Check
      OK
      All Test Mode DTCs are cleared.
      Result
      Result Proceed to
      OK A
      NG (for front) B
      NG (for rear) C

    B

    GO TO STEP 5 Click here

    C

    GO TO STEP 12 Click here

    A

  4. 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. Drive the vehicle at a speed of 54 km/h (34 mph) or more for at least 120 seconds.

    6. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1237 is not output. A
      DTC C1237 is output (for front). B
      DTC C1237 is output (for rear). C

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    GO TO STEP 8 Click here

    C

    GO TO STEP 15 Click here

  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 (for 1NR-FE): Click here

      for sensor rotor (for 1ZR-FE): Click here

      for sensor rotor (for 1ND-TV): 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

    CLEAN OR REPLACE FRONT SPEED SENSOR OR COMPONENT WITH SENSOR ROTOR

    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 A120 skid control ECU (brake actuator assembly) connector and A91 or A92 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
      A120-16 (FR+) - A91-1 (FR+) Always Below 1 Ω
      A120-16 (FR+) or A91-1 (FR+) - Body ground Always 10 kΩ or higher
      A120-4 (FR-) - A91-2 (FR-) Always Below 1 Ω
      A120-4 (FR-) or A91-2 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A120-19 (FL+) - A92-1 (FL+) Always Below 1 Ω
      A120-19 (FL+) or A92-1 (FL+) - Body ground Always 10 kΩ or higher
      A120-8 (FL-) - A92-2 (FL-) Always Below 1 Ω
      A120-8 (FL-) or A92-2 (FL-) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. RECONFIRM DTC


    1. Reconnect the A120 skid control ECU (brake actuator assembly) connector and A91 or A92 front speed sensor connector.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the ignition switch off.

    4. Start the engine.

    5. Drive the vehicle at a speed of 54 km/h (34 mph) or more for at least 120 seconds.

    6. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1237 is output. A
      DTC C1237 is not output. B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  8. REPLACE FRONT SPEED SENSOR


    1. Turn the ignition switch off.

    2. Replace the front speed sensor.

      Click here

      Note

      Check the speed sensor signal after replacement.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  9. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the ignition switch off.

    3. Start the engine.

    4. Drive the vehicle at a speed of 54 km/h (34 mph) or more for at least 120 seconds.

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1237 is output. A
      DTC C1237 is not output. B

    B

    END

    A

  10. REPLACE FRONT DRIVE OUTBOARD JOINT SHAFT ASSEMBLY


    1. Turn the ignition switch off.

    2. Replace the front speed sensor rotor (front drive outboard joint shaft assembly).

      Click here

      Tech Tips

      The front speed sensor rotor is incorporated into the front drive outboard joint shaft assembly.

      If the front speed sensor rotor needs to be replaced, replace the front drive outboard joint shaft assembly.

      Note

      Check the speed sensor signal after replacement.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  11. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the ignition switch off.

    3. Start the engine.

    4. Drive the vehicle at a speed of 54 km/h (34 mph) or more for at least 120 seconds.

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1237 is output. A
      DTC C1237 is not output. B

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    B

    END

  12. INSPECT SKID CONTROL SENSOR


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

      A01M0IJC06
      *A for RH *B for LH
      *a Front view of skid control sensor wire *b

      Front view of wire harness connector

      (to Sensor Side Connector)
      *c

      Front view of wire harness connector

      (to Vehicle Side Connector)

      		 - -

    2. Remove the skid control sensor wire.

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      h1-2 (RR+) - hL1-1 (RR+) Always Below 1 Ω
      h1-2 (RR+) - hL1-2 (RR-) Always 10 kΩ or higher
      h1-2 (RR+) or hL1-1 (RR+) - Body ground Always 10 kΩ or higher
      h1-1 (RR-) - hL1-2 (RR-) Always Below 1 Ω
      h1-1 (RR-) - hL1-1 (RR+) Always 10 kΩ or higher
      h1-1 (RR-) or hL1-2 (RR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      j1-2 (RL+) - jL1-1 (RL+) Always Below 1 Ω
      j1-2 (RL+) - jL1-2 (RL-) Always 10 kΩ or higher
      j1-2 (RL+) or jL1-1 (RL+) - Body ground Always 10 kΩ or higher
      j1-1 (RL-) - jL1-2 (RL-) Always Below 1 Ω
      j1-1 (RL-) - jL1-1 (RL+) Always 10 kΩ or higher
      j1-1 (RL-) or jL1-2 (RL-) - Body ground Always 10 kΩ or higher

      Note

      Check the speed sensor signal after replacement.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SKID CONTROL SENSOR WIRE Click here

    OK

  13. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - SKID CONTROL SENSOR WIRE)


    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the A120 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      A120-17 (RR+) - hL1-1 (RR+) Always Below 1 Ω
      A120-17 (RR+) or hL1-1 (RR+) - Body ground Always 10 kΩ or higher
      A120-29 (RR-) - hL1-2 (RR-) Always Below 1 Ω
      A120-29 (RR-) or hL1-2 (RR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A120-31 (RL+) - jL1-1 (RL+) Always Below 1 Ω
      A120-31 (RL+) or jL1-1 (RL+) - Body ground Always 10 kΩ or higher
      A120-18 (RL-) - jL1-2 (RL-) Always Below 1 Ω
      A120-18 (RL-) or jL1-2 (RL-) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  14. RECONFIRM DTC


    1. Install the skid control sensor wire.

    2. Reconnect the A120 skid control ECU (brake actuator assembly) connector.

    3. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    4. Turn the ignition switch off.

    5. Start the engine.

    6. Drive the vehicle at a speed of 54 km/h (34 mph) or more for at least 120 seconds.

    7. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1237 is output. A
      DTC C1237 is not output. B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  15. REPLACE REAR AXLE HUB AND BEARING ASSEMBLY


    1. Turn the ignition switch off.

    2. Replace the rear speed sensor rotor with rear speed sensor (rear axle hub and bearing assembly).

      Click here

      Tech Tips

      The rear speed sensor rotor is incorporated into the rear axle hub and bearing assembly.

      If the rear speed sensor rotor needs to be replaced, replace the rear axle hub and bearing assembly with rear speed sensor.

      Note

      Check the speed sensor signal after replacement.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  16. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the ignition switch off.

    3. Start the engine.

    4. Drive the vehicle at a speed of 54 km/h (34 mph) or more for at least 120 seconds.

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1237 is output. A
      DTC C1237 is not output. B

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    B

    END