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Home >> Lexus >> 2008 >> ES 350 >> Repair and Diagnosis >> Brakes >> Traction Control >> Brake Control >> Vehicle Stability Control System >> DTC C1251/51 Open in Pump Motor Circuit >> Inspection Procedure
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Inspection Procedure

NOTE: When replacing the brake actuator assembly, perform zero point calibration (See CALIBRATION  ).
  1. PERFORM ACTIVE TEST BY TECHSTREAM (ABS MOTOR RELAY) 
    1. Connect Techstream to the DLC3.
    2. Start the engine.
    3. Select the Active Test mode on Techstream.

      ABS/VSC/TRAC: 

      TESTER DISPLAY REFERENCE

      Tester Display Test Part Control Range Diagnostic Note
      Motor Relay ABS motor relay Relay ON/OFF Operating sound of relay (clicking sound) and motor can be heard
    4. Check the operating sound of the ABS motor relay and motor when operating it with Techstream.

      OK: The operating sound of the ABS motor relay and motor can be heard. 

    OK:  Go to step  3

    NG: Go to Next Step 

  2. INSPECT SKID CONTROL ECU (GND2 TERMINAL) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      A36-1 (GND2) - Body ground Always Below 1 Ω
      Fig 1: Identifying Skid Control ECU (GND2 Terminal)
      G05250438Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT) 

    OK: Go to Next Step 

  3. RECONFIRM DTC 
    1. Reconnect the skid control ECU connector.
    2. Turn the engine switch off.
    3. Clear the DTC (See DTC CHECK/CLEAR  ).
    4. Start the engine.
    5. Drive the vehicle at the speed of 7 km/h (4.3 mph) or more.
    6. Check if the same DTC is recorded (See DTC CHECK/CLEAR  ).

      Result 

      RESULT REFERENCE

      Condition Proceed to
      DTC (C1251/51) is not output A
      DTC (C1251/51) is output B

      HINT:

      • If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU, with the engine switch on (IG) and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits.
      • If a normal system code is output (the trouble code is not output), slightly jiggle the connectors, wire harness, and fuses of the brake actuator assembly. Make sure that no DTCs are output.
      • If any DTCs are output while jiggling a connector or wire harness of the brake actuator assembly (skid control ECU), inspect and repair the connector or wire harness.

    B: REPLACE BRAKE ACTUATOR ASSEMBLY 

    A: CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) 

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