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Home >> Lexus >> 2008 >> GX 470 >> Repair and Diagnosis >> Brakes >> Traction Control >> Brake Control >> 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 (master cylinder solenoid), perform zero point calibration (See CALIBRATION  ).
  1. PERFORM ACTIVE TEST BY TECHSTREAM (H/B MOTOR RELAY) 
    1. Connect Techstream to the DLC3.
    2. Turn the ignition switch to the ON position and push Techstream main switch ON.
    3. Start the engine.
    4. Select "Active Test" mode on Techstream.

      ABS/VSC/TRAC 

      DIAGNOSTIC NOTE

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

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

    OK: Go to step  4

    NG: Go to next step 

  2. INSPECT SKID CONTROL ECU (+BM TERMINAL) 
    1. Disconnect the skid control ECU connectors.
    2. Turn the ignition switch to the ON position.
    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      S37-2 (+BM1) - Body ground Ignition switch ON 10 to 14 V
      S38-2 (+BM2) - Body ground Ignition switch ON 10 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM CIRCUIT) 

    Fig 1: Inspecting Skid Control ECU (+BM Terminal)
    G05262737Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

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

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      S37-1 (GND1) - Body ground Below 1 Ω
      S37-32 (GND2) - Body ground Below 1 Ω
      S38-4 (GND3) - Body ground Below 1 Ω

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

    Fig 2: Inspecting Skid Control ECU (GND Terminal)
    G05262738Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  4. RECONFIRM DTC 
    1. Clear the DTC (See DTC CHECK/CLEAR  ).
    2. Turn the ignition switch off.
    3. Depress the brake pedal more than 20 times.
    4. Turn the ignition switch to the ON position.
    5. Wait until the pump motor stops.
    6. Depress the brake pedal several times until the pump motor turns on.
    7. Wait until the pump stops.
    8. Repeat ( f) and ( g) 3 more times.
    9. Check if the same DTC is detected (See DTC CHECK/CLEAR  ).

      HINT:

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

      Result 

      RESULT CHART

      Condition Proceed to
      DTC is output A
      DTC is not output B

    B: END 

    A: REPLACE HYDRAULIC BRAKE BOOSTER 

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