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Home >> Lexus >> 2008 >> LX 570 >> Repair and Diagnosis >> Brakes >> Brakes Control Systems >> Brake Control / Dynamic Control Systems >> Vehicle Stability Control System >> DTC C1253/53 Pump Motor Relay Malfunction >> Inspection Procedure
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Inspection Procedure

NOTE: When replacing the hydraulic brake booster assembly (master cylinder solenoid), perform zero point calibration (See CALIBRATION ).
  1. PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the Techstream on.
    3. Start the engine.
    4. Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.

      ABS/VSC/TRAC 

      ACTIVE TEST DETAIL

      Tester Display Test Part Control Range Diagnostic Note
      Motor Relay Motor relay Relay ON/OFF An operation sound of the motor can be heard.
    5. Check the operation sound of the motor individually when operating it with the Techstream.

    OK: The operation sound of the motor can be heard. 

    NG:  Go to step  3

    OK: Go to next step 

  2. RECONFIRM DTC 
    1. Clear the DTC (See DTC CHECK/CLEAR ).
    2. Turn the engine switch off.
    3. Depress the brake pedal more than 20 times.
    4. Turn the engine switch on (IG).
    5. Wait until the pump motor stops.
    6. Depress the brake pedal several times until the pump motor turns on. (Procedure A)
    7. Wait until the pump stops. (Procedure B)
    8. Repeat the above steps (procedure A and B) 3 more times.
    9. Check if the same DTC is output (See DTC CHECK/CLEAR ).

    HINT:

    Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

    Result 

    RESULT REFERENCE

    Result Proceed to
    DTC is output. A
    DTC is not output. B

    B: USE SIMULATION METHOD TO CHECK  (See HOW TO PROCEED WITH TROUBLESHOOTING )

    A: REPLACE MASTER CYLINDER SOLENOID  (See DISASSEMBLY )

  3. INSPECT SKID CONTROL ECU (+BM TERMINAL) 
    1. Disconnect the A24 and A25 skid control ECU connectors.
    2. Measure the voltage according to the value(s) in the table below.

    Standard Voltage 

    VOLTAGE SPECIFICATION

    Tester Connection Condition Specified Condition
    A24-2 (+BM1) - Body ground Always 11 to 14 V
    A25-2 (+BM2) - Body ground Always 11 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 1: Identifying A24 And A25 Skid Control ECU Connectors
    G05629900Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  4. INSPECT SKID CONTROL ECU (GND TERMINAL) 
    1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance 

    RESISTANCE SPECIFICATION

    Tester Connection Condition Specified Condition
    A24-1 (GND1) - Body ground Always Below 1 Ω
    A24-32 (GND2) - Body ground Always Below 1 Ω
    A25-4 (GND3) - Body ground Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying A24 And A25 Skid Control ECU Connectors
    G05629870Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  5. RECONFIRM DTC 
    1. Clear the DTC (See DTC CHECK/CLEAR ).
    2. Turn the engine switch off.
    3. Depress the brake pedal more than 20 times.
    4. Turn the engine switch on (IG).
    5. Wait until the pump motor stops.
    6. Depress the brake pedal several times until the pump motor turns on. (Procedure A)
    7. Wait until the pump stops. (Procedure B)
    8. Repeat the above steps (procedure A and B) 3 more times.
    9. Check if the same DTC is output (See DTC CHECK/CLEAR ).

    HINT:

    Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

    Result 

    RESULT REFERENCE

    Result Proceed to
    DTC is output. A
    DTC is not output. B

    B: USE SIMULATION METHOD TO CHECK  (See HOW TO PROCEED WITH TROUBLESHOOTING )

    A: REPLACE MASTER CYLINDER SOLENOID  (See DISASSEMBLY )

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