LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2017 >> RX 350 Base, FWD >> Repair and Diagnosis (Single Page) >> External Pages >> Different variant/trim >> Section 1 (Dynamic Torque Control AWD System - Diagnostics - Introduction) >> Dynamic Torque Control AWD System >> Precaution [08/2016 - 08/2019] >> Precaution [08/2016 - 08/2019]
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Precaution [08/2016 - 08/2019]

WARNING: This page is about a different variant/trim than selected.
  1. PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL 
    NOTE:

    When disconnecting the cable from the negative (-) battery terminal, initialize the following system(s) after the cable is reconnected:

    System See Procedure
    LKA/LDA System Refer to INITIALIZATION [08/2016 - 12/2017] , or refer to INITIALIZATION [12/2017 - 08/2019]
    Intelligent Clearance Sonar System
    Parking Assist Monitor System
    Panoramic View Monitor System
    Power Door Lock Control System
    Pre-collision System
    Power Back Door System
    Lighting System (w/ Automatic Headlight Beam Level Control System)
    AFS (Adaptive Front-lighting System)
  2. TROUBLESHOOTING PRECAUTION 
    NOTE:
    • Since the dynamic torque control AWD system may be influenced by a malfunction in other systems, be sure to check for DTCs in other systems first.
    • After installing the 4WD ECU assembly or a sensor, always perform a test mode inspection and check for DTCs.
    • When the 4WD ECU assembly is replaced with a known good one from another vehicle, it is necessary to perform calibration.

      Refer to CALIBRATION [09/2015 - ] 

      HINT: 

      When replacing the 4WD ECU assembly with a new one, it is not necessary to perform calibration.

    • If a CAN communication DTC is output, repair the malfunction in the communication line before troubleshooting the dynamic torque control AWD system.
    • The wiring used for each communication line is a twisted pair of wires that have an equal length. Do not temporarily repair a CAN communication line with a bypass wire or equivalent.
  3. "4WD CONTROL PREVENTION MODE" OR "VSC/TR(A)C/4WD CONTROL PREVENTION MODE" PROCEDURES FOR INSPECTION AND MAINTENANCE 
    NOTE:

    In the case of using a speedometer tester, brake tester, or chassis dynamometer, etc., there is some possibility of a speed differential between the front and rear wheels. Therefore, before performing the test, make sure to enter "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode".

    1. Entering and Canceling "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode" (When Using Techstream)

      HINT: 

      • The operation of the dynamic torque control AWD system can be prohibited by entering "4WD Control Prevention Mode".
      • The operation of both the dynamic torque control AWD system and the vehicle stability control system can be prohibited by entering "VSC/TR(A)C/4WD Control Prevention Mode".
      1. Enter "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode"
        WARNING:

        When using a drum tester while in "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode", secure the vehicle with chains for safety.

        NOTE:
        • "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode" is canceled when the engine switch is turned off. Therefore, when continuing the inspection after the engine switch has been turned off during inspection, it is necessary to re-enter "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode".
        • Do not drive the vehicle while in "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode".
        1. With the engine switch off, connect the Techstream to the DLC3.
        2. Turn the engine switch on (IG), and enter the following menus: Four Wheel Drive / Utility / 4WD Control Prevention Mode or VSC/TR(A)C/4WD Control Prevention Mode.
        3. Following the display on the Techstream screen, enter "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode".

          HINT: 

          • After entering "4WD Control Prevention Mode":
            1. Check that the AWD test mode message is displayed on the multi-information display.
          • After entering "VSC/TR(A)C/4WD Control Prevention Mode":
            1. Check that the AWD test mode message and TRAC OFF message are displayed on the multi-information display and that the VSC OFF indicator light is illuminated.

        Chassis > Four Wheel Drive > Utility 

        Tester Display
        4WD Control Prevention Mode

        Chassis > Four Wheel Drive > Utility 

        Tester Display
        VSC/TR(A)C/4WD Control Prevention Mode
      2. Cancel "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode"
        1. Turn the engine switch off, wait for 60 seconds or more, and cancel "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode".
          NOTE:

          Do not turn the engine switch off within 60 seconds of entering "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode". If the engine switch is turned off within 60 seconds, "4WD Control Prevention Mode" or "VSC/TR(A)C/4WD Control Prevention Mode" will continue when the engine switch is turned on (IG) again.

          HINT: 

          • When canceling "4WD Control Prevention Mode":
            1. Check that the AWD test mode message is no longer displayed on the multi-information display.
          • When canceling "VSC/TR(A)C/4WD Control Prevention Mode":
            1. Check that the AWD test mode message and TRAC OFF message are not displayed on the multi-information display and that the VSC OFF indicator light is not illuminated.
    2. Entering and Canceling "VSC/TR(A)C/4WD Control Prevention Mode" (When not using Techstream)

      HINT: 

      When entering "VSC/TR(A)C/4WD Control Prevention Mode" when not using the Techstream, operation of both the vehicle stability control system and the dynamic torque control AWD system is prohibited.

      1. Enter "VSC/TR(A)C/4WD Control Prevention Mode"
        WARNING:

        When using a drum tester while in "VSC/TR(A)C/4WD Control Prevention Mode", secure the vehicle with chains for safety.

        HINT: 

        • "VSC/TR(A)C/4WD Control Prevention Mode" is canceled when the engine switch is turned off. When continuing the inspection after the engine switch has been turned off during inspection, re-enter "VSC/TR(A)C/4WD Control Prevention Mode".
        • Do not drive the vehicle while in "VSC/TR(A)C/4WD Control Prevention Mode".
        • Perform the operation within 30 seconds of turning the engine switch on (IG).
        • If it cannot be confirmed that "VSC/TR(A)C/4WD Control Prevention Mode" has been entered, carry out the procedure again from step 1 after turning the engine switch off.
        • Fully depress or release the brake pedal to ensure that the stop light switch changes between ON and OFF respectively.
        • Fully apply or release the parking brake to ensure that the parking brake light in the combination meter assembly illuminates or turns off respectively.
        1. Turn the engine switch on (IG).
        2. With the parking brake applied, release and then depress the brake pedal 2 or more times consecutively, and then keep the brake pedal depressed.
        3. With the brake pedal depressed, release and then apply the parking brake 2 or more times consecutively, and then keep the parking brake applied.
        4. With the parking brake applied, release and then depress the brake pedal 2 or more times consecutively again.
        5. Check that the AWD test mode message and TRAC OFF message are displayed on the multi-information display and that the VSC OFF indicator light is illuminated.
      2. Cancel "VSC/TR(A)C/4WD Control Prevention Mode"
        1. Turn the engine switch off, wait for 60 seconds or more, and cancel "VSC/TR(A)C/4WD Control Prevention Mode".
          NOTE:

          Do not turn the engine switch off within 60 seconds of entering VSC/TR(A)C/4WD Control Prevention Mode". If the engine switch is turned off within 60 seconds, "VSC/TR(A)C/4WD Control Prevention Mode" will continue when the engine switch is turned on (IG) again.

          HINT: 

          Check that the AWD test mode message and TRAC OFF message are not displayed on the multi-information display and that the VSC OFF indicator light is not illuminated.