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Inspection Procedure

NOTE: When replacing the master cylinder solenoid, perform zero point calibration (See CALIBRATION  ).
  1. INSPECT DOWNHILL ASSIST CONTROL INDICATOR LIGHT 
    1. Disconnect the skid control ECU connector.
    2. Ground terminal HDCW of the skid control ECU.
    3. Turn the ignition switch to the ON position.
    4. Check that the downhill assist control indicator light comes on.

      OK: Downhill assist control indicator light comes on. 

    OK: REPLACE MASTER CYLINDER SOLENOID 

    NG: Go to Next Step 

  2. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - COMBINATION METER) 
    Fig 1: Identifying Skid Control ECU Connector Terminals S37 & Combination Meter Connector C12-14
    G05262790Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the combination meter connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Specified Condition
      S37-33 (HDCW) - C12-14 Below 1 Ω
      S37-33 (HDCW) - Body ground 10 kΩ or higher

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

    OK: Go to Next Step 

  3. INSPECT COMBINATION METER ASSEMBLY 
    1. Check the combination meter system (See HOW TO PROCEED WITH TROUBLESHOOTING ).

    NG: REPLACE COMBINATION METER ASSEMBLY 

    OK: Go to Next Step 

  4. INSPECT SKID CONTROL ECU (HDCS TERMINAL) 
    Fig 2: Identifying Skid Control ECU Connector S37
    G05262791Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the skid control ECU connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Condition Specified Condition
      S37-44 (HDCS) - Body ground Downhill assist control switch is pushed in Below 1 Ω

    OK: REPLACE MASTER CYLINDER SOLENOID 

    NG: Go to Next Step 

  5. INSPECT DOWNHILL ASSIST CONTROL SWITCH 
    Fig 3: Identifying Downhill Assist Control Switch
    G04965534Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the downhill assist control switch connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Condition Specified Condition
      D5-3 - D5-4 Switch is pushed in Below 1 Ω
      D5-3 - D5-4 Switch is not pushed in 10 kΩ or higher

    NG: REPLACE DOWNHILL ASSIST CONTROL SWITCH 

    OK: Go to Next Step 

  6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - DOWNHILL ASSIST CONTROL SWITCH) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Specified Condition
      S37-44 (HDCS) - D5-3 Below 1 Ω
      S37-44 (HDCS) - Body ground 10 kΩ or higher
      D5-4 - Body ground Below 1 Ω
      Fig 4: Identifying Skid Control ECU Connector Terminals S37
      G05262798Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

    OK: END 

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