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Home >> Lexus >> 2017 >> GS 450h Base >> Repair and Diagnosis (Single Page) >> Brakes >> Traction Control >> Electronically Controlled Brake System (DTC Codes 36, U0073/94, C1202/68 - C1314/14) >> Electronically Controlled Brake System >> DTC C1273/73: Low Output Signal of Rear Speed Sensor RH (Test Mode DTC); DTC C1274/74: Low Output Signal of Rear Speed Sensor LH (Test Mode DTC); DTC C1466/33: Rear Speed Sensor RH Circuit; DTC C1467/34: Rear Speed Sensor LH Circuit [09/2014 - ] >> Procedure
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DTC C1273/73: Low Output Signal of Rear Speed Sensor RH (Test Mode DTC); DTC C1274/74: Low Output Signal of Rear Speed Sensor LH (Test Mode DTC); DTC C1466/33: Rear Speed Sensor RH Circuit; DTC C1467/34: Rear Speed Sensor LH Circuit [09/2014 - ]: Procedure

  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION) 
    1. Using the Techstream, check for any momentary interruptions in the wire harness and connector corresponding to a DTC (See page. Refer to CHECK FOR INTERMITTENT PROBLEMS [09/2014 - ] ).
      ABS/VSC/TRAC

      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.

      HINT: 

      Perform the above inspection before removing the sensor and connector.

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  2

  2. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR) 
    1. Select the Data List on the Techstream (See page. Refer to DATA LIST / ACTIVE TEST [09/2014 - 10/2015] Refer to DATA LIST / ACTIVE TEST [10/2015 - ] ).
      ABS/VSC/TRAC

      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 Techstream.

      HINT: 

      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 (See page. Refer to OPERATION CHECK [09/2014 - 10/2015] Refer to OPERATION CHECK [10/2015 - ] ).

      OK

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

    Result:  NG

    NG 

    See step  5

    Result:  OK

    OK 

    See step  3

  3. PERFORM TEST MODE INSPECTION (SIGNAL CHECK) 
    1. Turn the power switch off.
    2. Perform the sensor check in the Test Mode procedure (See page. Refer to TEST MODE PROCEDURE [09/2014 - 10/2015] Refer to TEST MODE PROCEDURE [10/2015 - ] ).

      OK

      All Test Mode DTCs are cleared.

    Result:  NG

    NG 

    See step  5

    Result:  OK

    OK 

    See step  4

  4. RECONFIRM DTC 
    1. Turn the power switch off.
    2. Clear the DTCs (See page. Refer to DTC CHECK / CLEAR [09/2014 - ] ).
    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 (See page. Refer to DTC CHECK / CLEAR [09/2014 - ] ).

      Result

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

      HINT: 

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See page. Refer to PROBLEM SYMPTOMS TABLE [09/2014 - 10/2015] Refer to PROBLEM SYMPTOMS TABLE [10/2015 - ] ).

    Result:  A

    A 

    CHECK FOR INTERMITTENT PROBLEMS 

    (See page. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2014 - 10/2015] Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - ] )

    Result:  B

    B 

    See step  11

  5. CHECK REAR SPEED SENSOR INSTALLATION 
    1. Turn the power switch off.
      GTY522873Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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.

      TEXT IN ILLUSTRATION

      *a No clearance
      *b OK
      *c NG

    Result:  NG

    NG 

    INSTALL REAR SPEED SENSOR CORRECTLY 

    (See page. Refer to INSTALLATION [09/2014 - ] )

    Result:  OK

    OK 

    See step  6

  6. CHECK REAR SPEED SENSOR TIP 
    1. Remove the rear speed sensor (See page. Refer to REMOVAL [09/2014 - ] ).
    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 (See page. Refer to TEST MODE PROCEDURE [09/2014 - 10/2015] Refer to TEST MODE PROCEDURE [10/2015 - ] ).

    Result:  NG

    NG 

    CLEAN OR REPLACE REAR SPEED SENSOR 

    Result:  OK

    OK 

    See step  7

  7. CHECK REAR SPEED SENSOR ROTOR 
    1. Remove the rear axle hub (rear speed sensor rotor) (See page. Refer to REMOVAL [09/2014 - ] ).
    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 (See page. Refer to TEST MODE PROCEDURE [09/2014 - 10/2015] Refer to TEST MODE PROCEDURE [10/2015 - ] ).

      HINT: 

      • 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.

    Result:  NG

    NG 

    CLEAN OR REPLACE REAR SPEED SENSOR ROTOR 

    Result:  OK

    OK 

    See step  8

  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

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  9

  9. INSPECT SKID CONTROL ECU ASSEMBLY (SENSOR OUTPUT) 
    1. Reconnect the skid control ECU assembly connector.
      GTY528773Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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
      TEXT IN ILLUSTRATION

      *A for RH
      *B for LH
      *a Front view of wire harness connector
      (to Rear Speed Sensor)

    Result:  NG

    NG 

    REPLACE SKID CONTROL ECU ASSEMBLY 

    (See page. Refer to REMOVAL [09/2014 - ] )

    Result:  OK

    OK 

    See step  10

  10. RECONFIRM DTC 
    1. Turn the power switch off.
    2. Reconnect the rear speed sensor connector.
    3. Clear the DTCs (See page. Refer to DTC CHECK / CLEAR [09/2014 - ] ).
    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 (See page. Refer to DTC CHECK / CLEAR [09/2014 - ] ).

      Result

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

      HINT: 

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See page. Refer to PROBLEM SYMPTOMS TABLE [09/2014 - 10/2015] Refer to PROBLEM SYMPTOMS TABLE [10/2015 - ] ).

    Result:  B

    B 

    CHECK FOR INTERMITTENT PROBLEMS 

    (See page. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2014 - 10/2015] Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - ] )

    Result:  A

    A 

    See step  11

  11. REPLACE REAR SPEED SENSOR 
    1. Turn the power switch off.
    2. Replace the rear speed sensor (See page. Refer to REMOVAL [09/2014 - ] ).
      NOTE:

      Check the speed sensor signal after replacement (See page. Refer to TEST MODE PROCEDURE [09/2014 - 10/2015] Refer to TEST MODE PROCEDURE [10/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  12

  12. RECONFIRM DTC 
    1. Clear the DTCs (See page. Refer to DTC CHECK / CLEAR [09/2014 - ] ).
    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 (See page. Refer to DTC CHECK / CLEAR [09/2014 - ] ).

      Result

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

      HINT: 

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See page. Refer to PROBLEM SYMPTOMS TABLE [09/2014 - 10/2015] Refer to PROBLEM SYMPTOMS TABLE [10/2015 - ] ).

    Result:  B

    B 

    END 

    Result:  A

    A 

    See step  13

  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) (See page. Refer to REMOVAL [09/2014 - ] ).

      HINT: 

      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 (See page. Refer to TEST MODE PROCEDURE [09/2014 - 10/2015] Refer to TEST MODE PROCEDURE [10/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  14

  14. RECONFIRM DTC 
    1. Clear the DTCs (See page. Refer to DTC CHECK / CLEAR [09/2014 - ] ).
    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 (See page. Refer to DTC CHECK / CLEAR [09/2014 - ] ).

      Result

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

    Result:  A

    A 

    REPLACE SKID CONTROL ECU ASSEMBLY 

    (See page. Refer to REMOVAL [09/2014 - ] )

    Result:  B

    B 

    END 

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