ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1273/73, C1274/74, C1466/33, C1467/34

DTC Code DTC Name
C1273/73 Low Output Signal of Rear Speed Sensor RH (Test Mode DTC)
C1274/74 Low Output Signal of Rear Speed Sensor LH (Test Mode DTC)
C1466/33 Rear Speed Sensor RH Circuit
C1467/34 Rear Speed Sensor LH Circuit

DESCRIPTION

The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU assembly. These signals are used for ABS control.

DTCs C1273/73 and C1274/74 can be cleared when the speed sensor sends a wheel speed signal or when Test Mode ends. DTCs C1273/73 and C1274/74 are output only in Test Mode.

Tech Tips

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

A01FR37E01
DTC Code INF Code DTC Detection Condition Trouble Area
C1466/33 277 At a vehicle speed of 10 km/h (6 mph) or more, an open or short in the sensor signal circuit of the abnormal wheel continues for 1 second or more.

  • Rear speed sensor RH

  • Speed sensor circuit

  • Sensor installation

  • Speed sensor rotor

  • Skid control ECU assembly
↑ 278 More than one speed sensor circuit signal is abnormal. ↑
↑ 279 Speed sensor circuit signal is open for 0.5 seconds or more. ↑
↑ 280 A momentary interruption of the sensor signal from the speed sensor occurs 255 times or more. ↑
↑ 281 Frequency of 2.5 kHz or more is input.

  • Rear speed sensor RH

  • Speed sensor circuit

  • Speed sensor rotor

  • Skid control ECU assembly
↑ 288

Either of the following is detected:


  1. With the voltage of IG1 terminal at 9.5 V or more, the sensor power supply voltage decreases for 0.5 seconds or more.

  2. With the voltage of IG1 terminal at 9.5 V or more, the sensor power supply voltage fluctuates for 60 seconds or more.

  • Speed sensor circuit

  • Skid control ECU assembly
C1467/34 290 At a vehicle speed of 10 km/h (6 mph) or more, an open or short in the sensor signal circuit of the abnormal wheel continues for 1 second or more.

  • Rear speed sensor LH

  • Speed sensor circuit

  • Sensor installation

  • Speed sensor rotor

  • Skid control ECU assembly
↑ 291 More than one speed sensor circuit signal is abnormal. ↑
↑ 292 Speed sensor circuit signal is open for 0.5 seconds or more. ↑
↑ 293 A momentary interruption of the sensor signal from the speed sensor occurs 255 times or more. ↑
↑ 294 Frequency of 2.5 kHz or more is input.

  • Rear speed sensor LH

  • Speed sensor circuit

  • Speed sensor rotor

  • Skid control ECU assembly
↑ 301

Either of the following is detected:


  1. With the voltage of IG1 terminal at 9.5 V or more, the sensor power supply voltage decreases for 0.5 seconds or more.

  2. With the voltage of IG1 terminal at 9.5 V or more, the sensor power supply voltage fluctuates for 60 seconds or more.

  • Speed sensor circuit

  • Skid control ECU assembly

C1273/73

C1274/74

 - Detected only during Test Mode.

  • Rear speed sensor RH/LH

  • Sensor installation

  • Speed sensor rotor

Tech Tips


  • DTCs C1466/33 and C1273/73 are for the rear speed sensor RH.

  • DTCs C1467/34 and C1274/74 are for the rear speed sensor LH.

WIRING DIAGRAM

A01FVHSE01

INSPECTION PROCEDURE

Note

When replacing the skid control ECU assembly, perform initialization and calibration of the linear solenoid valve Click here.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)


    1. Using the GTS, check for any momentary interruptions in the wire harness and connector corresponding to a DTC Click here.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      RR Speed Open Rear speed sensor RH open detection / Error or Normal

      Error: Momentary interruption

      Normal: Normal

      		 -
      RL Speed Open Rear speed sensor LH 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

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. READ VALUE USING GTS (REAR SPEED SENSOR)


    1. Select the Data List on the GTS Click here.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      RR Wheel Speed Rear wheel speed sensor RH / 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 / 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

    2. 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 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 GTS is similar to the speed indicated on the speedometer.

    NG

    CHECK REAR SPEED SENSOR INSTALLATION Click here

    OK

  3. PERFORM TEST MODE INSPECTION (SIGNAL CHECK)


    1. Turn the power switch off.

    2. Perform the sensor check in the Test Mode procedure Click here.

      OK
      All Test Mode DTCs are cleared.

    NG

    CHECK REAR SPEED SENSOR INSTALLATION Click here

    OK

  4. RECONFIRM DTC


    1. Turn the power switch off.

    2. Clear the DTCs Click here.

    3. Turn the power switch on (READY).

    4. Drive the vehicle at a speed of 10 km/h (6 mph) or more for at least 60 seconds.

    5. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTCs (C1466/33 and C1467/34) are not output A
      DTCs (C1466/33 and/or C1467/34) 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 REAR SPEED SENSOR Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  5. CHECK REAR SPEED SENSOR INSTALLATION


    1. A01FV67E08
      Text in Illustration
      *a No clearance
      *b OK
      *c NG

      Turn the power switch off.

    2. Check the speed sensor installation.

      OK
      There is no clearance between the sensor and the rear axle carrier.
      The installation bolt is tightened properly.

    NG

    INSTALL REAR SPEED SENSOR CORRECTLY Click here

    OK

  6. CHECK REAR SPEED SENSOR TIP


    1. Remove the rear speed sensor Click here.

    2. Check the speed sensor tip.

      OK
      The sensor tip is free of scratches, oil and foreign matter.

      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.


    NG

    CLEAN OR REPLACE REAR SPEED SENSOR

    OK

  7. CHECK REAR SPEED SENSOR ROTOR


    1. Remove the rear axle hub (rear speed sensor rotor) Click here.

    2. Check the speed sensor rotor.

      OK
      No scratches, oil, or foreign matter on the rotors.

      Note

      Check the speed sensor signal after cleaning or replacement 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 it together with the rear axle hub and bearing assembly.


    NG

    CLEAN OR REPLACE REAR SPEED SENSOR ROTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU ASSEMBLY - REAR SPEED SENSOR)


    1. Install the rear speed sensor and rear axle hub (rear speed sensor rotor).

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

    3. Disconnect the A14 or A16 skid control ECU assembly connector.

    4. Disconnect the U32 or T30 rear 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
      A16-11 (RR+) - T30-1 (RR+) Always Below 1 Ω
      A16-11 (RR+) - Body ground Always 10 kΩ or higher
      A16-10 (RR-) - T30-2 (RR-) Always Below 1 Ω
      A16-10 (RR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A14-11 (RL+) - U32-1 (RL+) Always Below 1 Ω
      A14-11 (RL+) - Body ground Always 10 kΩ or higher
      A14-10 (RL-) - U32-2 (RL-) Always Below 1 Ω
      A14-10 (RL-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. INSPECT SKID CONTROL ECU ASSEMBLY (SENSOR OUTPUT)


    1. A01FQ1HE02
      Text in Illustration
      *A for RH
      *B for LH
      *a

      Front view of wire harness connector

      (to Rear Speed Sensor)

      Reconnect the skid control ECU assembly connector.

    2. Turn the power 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
      T30-1 (RR+) - Body ground Power switch on (IG) 7.6 to 14 V
      for LH
      Tester Connection Switch Condition Specified Condition
      U32-1 (RL+) - Body ground Power switch on (IG) 7.6 to 14 V

    NG

    REPLACE SKID CONTROL ECU ASSEMBLY Click here

    OK

  10. RECONFIRM DTC


    1. Turn the power switch off.

    2. Reconnect the rear speed sensor connector.

    3. Clear the DTCs Click here.

    4. Turn the power switch on (READY).

    5. Drive the vehicle at a speed of 10 km/h (6 mph) or more for at least 60 seconds.

    6. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTCs (C1466/33 and/or C1467/34) are output A
      DTCs (C1466/33 and C1467/34) are not 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

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  11. REPLACE REAR SPEED SENSOR


    1. Turn the power switch off.

    2. Replace the rear speed sensor Click here.

      Note

      Check the speed sensor signal after replacement Click here.


    NEXT

  12. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Turn the power switch on (READY).

    3. Drive the vehicle at a speed of 10 km/h (6 mph) or more for at least 60 seconds.

    4. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTCs (C1466/33 and/or C1467/34) are output A
      DTCs (C1466/33 and C1467/34) are not 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

    END

    A

  13. REPLACE REAR SPEED SENSOR ROTOR


    1. Turn the power switch off.

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

      Note

      Check the speed sensor signal after replacement Click here.


    NEXT

  14. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Turn the power switch on (READY).

    3. Drive the vehicle at a speed of 10 km/h (6 mph) or more for at least 60 seconds.

    4. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTCs (C1466/33 and/or C1467/34) are output A
      DTCs (C1466/33 and C1467/34) are not output B

    B

    END

    A

    REPLACE SKID CONTROL ECU ASSEMBLY Click here