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Home >> Lexus >> 2007 >> LS 460L >> Repair and Diagnosis >> Brakes >> Traction Control >> Brake Control >> Electronically Controlled Brake System >> DTC C1378/44 Capacitor Communication Malfunction >> 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. INSPECT BRAKE CONTROL POWER SUPPLY 
      Fig 1: Identifying S49 Power Supply Connector
      G04949669Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the S49 power supply connector.
    2. Measure the voltage according to the value (s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      S49-5 (IG1)-Body ground Always 11 to 14 V
    3. Measure the resistance according to the value (s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      S49-14 (GND) - Body ground Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1, GND CIRCUIT) 

    OK: GO TO NEXT STEP 

  2. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE CONTROL POWER SUPPLY) 
      Fig 2: Identifying A21 ECU Connector And S49 Power Supply Connector
      G04949670Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the A21 ECU connector.
    2. Disconnect the S49 power supply connector.
    3. Measure the resistance according to the value (s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      A19-8 (ENA)-S49-12 (ENA) Always Below 1 Ω
      A21-41 (FAIL)-S49-13 (FAIL) Always Below 1 Ω
      A19-8 (ENA) - Body ground Always 10 kΩ or higher
      A21-41 (FAIL)-Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: GO TO NEXT STEP 

  3. RECONFIRM DTC 
    1. Clear the DTC (see DTC CHECK/CLEAR  ).
    2. Turn the engine switch on (IG).
    3. Check if the same DTC is recorded (see DTC CHECK/CLEAR  ).

      HINT:

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

      Result 

      RESULT REFERENCE

      Result Proceed to
      DTC (C1378/44) is output A
      DTC (C1378/44) is not output B

    B: END 

    A: GO TO NEXT STEP 

  4. CHECK FREEZE FRAME DATA 
    1. Check the information code from the "FREEZE FRAME DATA" memorized when the DTC (C1378/44) is stored (see FREEZE FRAME DATA  ).

      Result 

      RESULT REFERENCE

      Result Proceed to
      Information code is not output A
      Information code (112) is output B

    B: REPLACE BRAKE CONTROL POWER SUPPLY (See  REMOVAL   ) 

    A: GO TO NEXT STEP 

    REPLACE SKID CONTROL ECU (See  REMOVAL   ) 

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