FixVault
Home › Toyota › 2008 › Tacoma X-Runner › Repair and Diagnosis › Brakes › Traction Control › Brake Control › Vehicle Stability Control System › Downhill Assist Control Indicator Light does not Come ON › Inspection Procedure

Inspection Procedure

  1. CHECK DOWNHILL ASSIST CONTROL INDICATOR LIGHT 
    1. Disconnect the skid control ECU connector.
    2. Turn the ignition switch to the ON position.
    3. Ground terminal HDCW of the skid control ECU.
    4. Check downhill assist control indicator light.

      OK 

      ASSIST CONTROL INDICATOR LIGHT CONDITION CHART

      HDCW - GND Condition Illumination Condition
      Connecting ON
      Disconnecting OFF
    5. Turn the ignition switch to OFF.
    6. Reconnect the skid control ECU connector.

    NG:  Go to step  3

    Fig 1: Identifying Skid Control ECU Connectors
    G05199330Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  2. INSPECT DOWNHILL ASSIST CONTROL SWITCH 
    1. Remove the downhill assist control switch.
    2. Disconnect the downhill assist control switch connector.
    3. Measure the resistance.

      Standard 

      RESISTANCE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      D8-3 - D8-4 Released 10 kΩ or higher
      D8-3 - D8-4 Pushed in Below 1 Ω
    4. Reconnect the downhill assist control switch connector.
    5. Reinstall the downhill assist control switch connector.
      Fig 2: Inspecting Downhill Assist Control Switch
      G05199331Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE DOWNHILL ASSIST CONTROL SWITCH 

    OK: Go to Next Step 

  3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - DOWNHILL ASSIST CONTROL SWITCH) 
    1. Disconnect the skid control ECU connector.
    2. Disconnect the downhill assist control switch connector.
    3. Measure the resistance.

      Standard 

      RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      S1-44 (HDCS) - D8-3 Below 1 Ω
      S1-44 (HDCS) - Body ground 10 kΩ or higher
      D8-4 - Body ground Below 1 Ω
    4. Reconnect the downhill assist control switch connector.
    5. Reconnect the skid control ECU connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying Downhill Assist Control Switch & Skid Control ECU Connectors
    G05678237Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE MASTER CYLINDER SOLENOID 

  4. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - COMBINATION METER) 
    1. Disconnect the skid control ECU connector.
    2. Disconnect the combination meter connector.
    3. Measure the resistance.

      Standard 

      RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      S1-33 (HDCW) - C10-13 Below 1 Ω
      S1-33 (HDCW) - Body ground 10 kΩ or higher
    4. Reconnect the combination meter connector.
    5. Reconnect the skid control ECU connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 4: Identifying Combination Meter & Skid Control ECU Connectors
    G05199326Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  5. INSPECT COMBINATION METER ASSEMBLY 
    1. Check the combination meter system. (See COMBINATION METER ).

      OK: Combination meter is normal. 

    NG: REPLACE COMBINATION METER ASSEMBLY 

    OK: CHECK FOR INTERMITTENT PROBLEMS 

About FixVault