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Home >> Lexus >> 2008 >> GS 450h >> Repair and Diagnosis (Single Page) >> Brakes >> Traction Control >> Brake Control >> Electronically Controlled Brake System >> DTC C0200/31 Front Speed Sensor RH Circuit; DTC C0205/32 Front Speed Sensor LH Circuit; DTC C1271/71 Low Output Signal of Front Speed Sensor RH (Test Mode DTC); DTC C1272/72 Low Output Signal of Front Speed Sensor LH (Test Mode DTC) >> Inspection Procedure
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Inspection Procedure

NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration (see INITIALIZATION  ).
  1. CHECK WIRE HARNESS (MOMENTARY INTERRUPTION) 
    1. Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC (see CHECK FOR INTERMITTENT PROBLEMS  ).

      ABS/VSC/TRAC: 

      TESTER DISPLAY REFERENCE CHART

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Speed Open FR speed sensor open detection / ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
      FL Speed Open FL speed sensor 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.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (SPEED SENSOR CIRCUIT) 

    OK: Go to next step 

  2. READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch ON (IG).
    3. Select the Data List mode on the Techstream.

      ABS/VSC/TRAC: 

      TESTER DISPLAY REFERENCE CHART

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Wheel Speed Wheel speed sensor (FR) reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Actual wheel speed Similar speed as indicated on speedometer
      FL Wheel Speed Wheel speed sensor (FL) reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Actual wheel speed Similar speed as indicated on speedometer
    4. Check that the speed value output from the speed sensor displayed on the Techstream and the speed value displayed on the speedometer are almost the same when driving the vehicle.

      OK: 

      The speed value output from the speed sensor displayed on the Techstream is the same as the actual vehicle speed. 

      ABS/VSC/TRAC: 

      TESTER DISPLAY REFERENCE CHART

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Wheel Direction Wheel direction (FR)/ FORWARD or BACK FORWARD: Forward BACK: Back -
      FL Wheel Direction Wheel direction (FL) / FORWARD or BACK FORWARD: Forward BACK: Back -
    5. Check that the sensor signal conforms to the wheel direction.

      OK: 

      The wheel direction is displayed. 

    NG:  Go to step  5

    OK: Go to next step 

  3. PERFORM TEST MODE (SIGNAL CHECK) 
    1. Clear the DTC (see DTC CHECK/CLEAR  ).
    2. Perform sensor signal check in "TEST MODE PROCEDURE " .

      OK: 

      All Test Mode DTCs are erased. 

    NG:  Go to step  5

    OK: Go to next step 

  4. RECONFIRM DTC 
    1. Clear the DTC (see DTC CHECK/CLEAR  ).
    2. Turn the power switch ON (IG).
    3. Drive the vehicle at the speed of 32 km/h (20 mph) or more for 60 seconds or more.
    4. Check if the same DTCs are recorded (see DTC CHECK/CLEAR  ).

      Result 

      RESULT REFERENCE

      Condition Proceed to
      DTCs (C0200/31 and C0205/32) are not output A
      DTCs (C0200/31 and C0205/32) are output B

      HINT:

      If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step (see PROBLEM SYMPTOMS TABLE  ).

    B:  Go to step  11

    A: END 

  5. INSPECT FRONT SPEED SENSOR INSTALLATION 
    1. Check the sensor installation.

      OK: 

      There is no clearance between the sensor and the front steering knuckle. 

      NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE  ).
      Fig 1: Identifying Clearance Between Sensor And Front Steering Knuckle
      G05816311Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CHECK AND REPLACE FRONT SPEED SENSOR 

    OK: Go to next step 

  6. INSPECT FRONT SPEED SENSOR TIP 
    1. Remove the front speed sensor.
    2. Check the sensor tip.

      OK: 

      No scratches or foreign matter on the sensor tip. 

      NOTE: Check the speed sensor signal after cleaning/ replacement (see TEST MODE PROCEDURE  ).

    NG: CLEAN OR REPLACE FRONT SPEED SENSOR 

    OK: Go to next step 

  7. CHECK WIRE HARNESS (FRONT SPEED SENSOR WIRE) 
    1. Disconnect the t1 sensor wire.
    2. Disconnect the ml sensor wire.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance: 

      for RH 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      t1 ("A"-2) - t1 ("B"-1) Below 1 Ω
      t1 ("A"-2) - t1 ("B"-2) 10 kΩ or higher
      t1 ("A"-2) - Body ground 10 kΩ or higher
      t1 ("A"-1) - t1 ("B"-2) Below 1 Ω
      t1 ("A"-1) - t1 ("B"-1) 10 kΩ or higher
      t1 ("A"-1) - Body ground 10 kΩ or higher

      for LH 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      m1 ("A"-2) - m1 ("B"-1) Below 1 Ω
      m1 ("A"-2) - ml ("B"-2) 10 kΩ or higher
      m1 ("A"-2) - Body ground 10 kΩ or higher
      m1 ("A"-1) - m1 ("B"-2) Below 1 Ω
      m1 (A"-1) - m1 ("B"-1) 10 kΩ or higher
      m1 ("A"-1) - Body ground 10 kΩ or higher
      Fig 2: Identifying Ml And T1 Sensor Wire
      G05816312Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE  ).

    NG: REPLACE SKID CONTROL SENSOR WIRE 

    OK: Go to next step 

  8. CHECK WIRE HARNESS (SKID CONTROL ECU - FRONT SPEED SENSOR) 
    1. Disconnect the A13 and A15 ECU connectors.
    2. Disconnect the t1 sensor connector.
    3. Disconnect the ml sensor connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard resistance: 

      for RH 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      A13-15 (FR+) - t1-2 Below 1 Ω
      A13-28 (FR-) - t1-1 Below 1 Ω
      A13-15 (FR+) - Body ground 10 kΩ or higher
      A13-28 (FR-) - Body ground 10 kΩ or higher

      for LH 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      A15-15 (FL+) - m1-2 Below 1 Ω
      A15-29 (FL-) - m1-1 Below 1 Ω
      A15-15 (FL+) - Body ground 10 kΩ or higher
      A15-29 (FL-) - Body ground 10 kΩ or higher
      5. Fig 3: Identifying A13, A15 ECU, T1 And Ml Sensor Connectors
      G05816313Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  9. CHECK SKID CONTROL ECU (SENSOR INPUT VOLTAGE) 
    1. Reconnect the A13 and A15 ECU connectors.
    2. Disconnect the t1 sensor connector.
    3. Disconnect the ml sensor connector.
    4. Turn the power switch ON (IG).
    5. Measure the voltage according to the value(s) in the table below.
      Fig 4: Identifying T1 And Ml Sensor Connectors
      G05816314Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      t1-2 - Body ground Power switch ON (IG) 6.7 to 14 V
      m1-2 - Body ground Power switch ON (IG) 6.7 to 14 V

    NG: REPLACE SKID CONTROL ECU  (See REMOVAL  )

    OK: Go to next step 

  10. RECONFIRM DTC 
    1. Clear the DTC (see DTC CHECK/CLEAR  ).
    2. Turn the power switch ON (READY).
    3. Drive the vehicle at the speed of 32 km/h (20 mph) or more for 60 seconds or more.
    4. Check if the same DTCs are recorded (see DTC CHECK/CLEAR  ).

      HINT:

      Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

      Result 

      RESULT REFERENCE

      Condition Proceed to
      DTCs (C0200/31 and C0205/32) are not output A
      DTCs (C0200/31 and C0205/32) are output B

      HINT:

      If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step (see PROBLEM SYMPTOMS TABLE  ).

    B: Go to step 11 

    A: END 

  11. REPLACE FRONT SPEED SENSOR 
    1. Replace the front speed sensor (see REMOVAL  ).
      NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE  ).
  12. RECONFIRM DTC 
    1. Clear the DTC (see DTC CHECK/CLEAR  ).
    2. Turn the power switch ON (READY).
    3. Drive the vehicle at the speed of 32 km/h (20 mph) or more for 60 seconds or more.
    4. Check if the same DTCs are recorded (see DTC CHECK/CLEAR  ).

      HINT:

      Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

      Result 

      RESULT REFERENCE

      Condition Proceed to
      DTCs (C0200/31 and C0205/32) are output A
      DTCs (C0200/31 and C0205/32) are not output B

      HINT:

      If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step (see PROBLEM SYMPTOMS TABLE  ).

    B: END 

    A: Go to next step 

  13. INSPECT SPEED SENSOR ROTOR 
    1. Remove the speed sensor rotor.
    2. Check the sensor rotor.

      OK: 

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

      NOTE: Check the speed sensor signal after cleaning/ replacement (see TEST MODE PROCEDURE  ).

    NG: CLEAN OR REPLACE SPEED SENSOR ROTOR 

    OK: REPLACE SKID CONTROL ECU  (See REMOVAL  )

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