Precaution [10/2022 - ]

WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL
NOTE:
- After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) battery terminal.
  Refer to BEFORE DISCONNECTING BATTERY [10/2022 - ]
- When disconnecting and reconnecting the battery.
  Refer to WORK PROCEDURE [10/2022 - ]
  
  HINT:
  
  When disconnecting and reconnecting the battery, there is an automatic learning function that completes learning when the respective system is used.
  
  Refer to AUTOMATIC LEARNING CHART [10/2022 - 08/2023] , or refer to AUTOMATIC LEARNING CHART [08/2023 - ]
- To prevent the key from being locked in the vehicle, make sure to enter e-latch inspection mode and enable the manual release handle before disconnecting the cable from the negative (-) battery terminal.
  Refer to INSPECTION MODE PROCEDURE [10/2022 - ]
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 the other systems.
- After performing repairs, clear the DTCs and check that the DTCs are not output again.
- Replace the 4WD ECU assembly with a new one.
- When the 4WD ECU assembly is replaced, before removing the 4WD ECU assembly, it is necessary to perform ECU Data Save to save the original 4WD ECU assembly information.
  Refer to CALIBRATION [10/2022 - ]
- When the 4WD ECU assembly is replaced, it is necessary to perform the following in order: ECU Configuration and ECU Data Write.
  Refer to CALIBRATION [10/2022 - ]
- When the 4WD linear solenoid (electro magnetic control coupling sub-assembly) is replaced, it is necessary to perform ECU Data Write (when replacing 4WD linear solenoid (electro magnetic control coupling sub-assembly)).
  Refer to CALIBRATION [10/2022 - ]
- When the yaw rate and acceleration sensor (airbag ECU assembly) is replaced, it is necessary to perform ECU Data Initialization.
  Refer to CALIBRATION [10/2022 - ]

PRECAUTION WHEN USING SPEEDOMETER TESTER

NOTE:

A tester with a load setting mechanism for 2 wheels only cannot be used by itself.
Perform the inspection on the front wheels.
Do not start off, accelerate or decelerate suddenly.
The vehicle speed should be 60 km/h (37 mph) or less. (When a free roller is in use, the vehicle speed should be 50 km/h (31 mph) or less)
The driving time should be within 1 minute.

Method for entering AWD control prohibited mode
NOTE:
- AWD control prohibited mode ends by turning the ignition switch off. Therefore, in order to continue inspection after the ignition switch is turned off, perform the procedure to enter AWD control prohibited mode again.
- Do not drive the vehicle with AWD control prohibited mode still active.
- Perform steps (*B) through (*F) within 120 seconds.
- If entering AWD control prohibited mode cannot be confirmed, turn the ignition switch off and repeat the procedure from step (*A).
- When turning the brake pedal ON/OFF, securely perform the action of depressing/releasing the pedal until the stop light switch turns on/off.
- When turning the parking brake ON/OFF, perform the action of releasing/applying the brake until the parking brake indicator light in the combination meter assembly turns on/off.
1. Ensure that the ignition switch is off and the engine is stopped (Step "A").
2. Turn the ignition switch ON (Step "B").
3. Apply the parking brake (Step "C").
4. Depress and release the brake pedal twice (Step "D").
5. While holding the brake pedal down, release and apply the parking brake twice (Step "E").
6. With the parking brake applied, depress and release the brake pedal twice (Step "F").
7. Check that "AWD TEST MODE" is displayed on the multi-information display (Step "G"). (Check that AWD control is prohibited)

When using speedometer tester

Place the front wheels onto the roller.

Place the rear wheels onto the free roller or safety stand.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	Safety stand	*2	Free roller
*a	When using drum tester	*b	AWD control operation prohibited condition

Secure the vehicle with lock chains.
HINT:

The position of the lock chain in the illustration is for reference only.
With the vehicle in shift state D, measure the vehicle speed while increasing the speed gradually.
Slowly decelerate by the brake and stop the vehicle after the measurement.
NOTE:
Do not use the parking brake. If brake is applied only on the rear wheels during high engine speed, it may cause AWD function effectiveness to decline, drivetrain parts to malfunction or the vehicle to move unexpectedly.

Cancel AWD control prohibited mode
1. Turn the ignition switch off, wait for 60 seconds or more and cancel AWD control prohibited mode.
  NOTE:
  Turn the ignition switch off when 60 seconds or more have elapsed since the AWD control prohibited mode was entered. If the ignition switch is turned off within 60 seconds, AWD control prohibited mode continues when the ignition switch is turned ON again.
2. Check that "AWD TEST MODE" is not displayed on the multi-information display. (Check AWD control starts)

PRECAUTION WHEN USING BRAKE TESTER
NOTE:
- A tester with a load measurement mechanism cannot be used.
- A high-speed type brake tester cannot be used.
1. Method for entering AWD control prohibited mode
  NOTE:
  - AWD control prohibited mode ends by turning the ignition switch off. Therefore, in order to continue inspection after the ignition switch is turned off, perform the procedure to enter AWD control prohibited mode again.
  - Do not drive the vehicle with AWD control prohibited mode still active.
  - Perform steps (*B) through (*F) within 120 seconds.
  - If entering AWD control prohibited mode cannot be confirmed, turn the ignition switch off and repeat the procedure from step (*A).
  - When turning the brake pedal ON/OFF, securely perform the action of depressing/releasing the pedal until the stop light switch turns on/off.
  - When turning the parking brake ON/OFF, perform the action of releasing/applying the brake until the parking brake indicator light in the combination meter assembly turns on/off.
  1. Ensure that the ignition switch is off and the engine is stopped (Step "A").
  2. Turn the ignition switch ON (Step "B").
  3. Apply the parking brake (Step "C").
  4. Depress and release the brake pedal twice (Step "D").
  5. While holding the brake pedal down, release and apply the parking brake twice (Step "E").
  6. With the parking brake applied, depress and release the brake pedal twice (Step "F").
  7. Check that "AWD TEST MODE" is displayed on the multi-information display (Step "G"). (Check that AWD control is prohibited)
2. When using brake tester
  1. Place the wheels to be tested (front or rear) onto the roller.
  2. Select shift state N.
  3. Drive the roller of the brake tester and measure.
    HINT:
    
    The driving time should be within 1 minute.
3. Cancel AWD control prohibited mode
  1. Turn the ignition switch off, wait for 60 seconds or more and cancel AWD control prohibited mode.
    NOTE:
    Turn the ignition switch off when 60 seconds or more have elapsed since the AWD control prohibited mode was entered. If the ignition switch is turned off within 60 seconds, AWD control prohibited mode continues when the ignition switch is turned ON again.
  2. Check that "AWD TEST MODE" is not displayed on the multi-information display. (Check AWD control starts)

PRECAUTION WHEN USING CHASSIS DYNAMOMETER

for 2-wheel Chassis Dynamometer or 4-wheel Driven Chassis Dynamometer (Electric Front/back Synchronized Type):
Disconnect the propeller shaft assembly and 4WD ECU assembly connector and set the system to the AWD control operation prohibited condition.

4WD ECU assembly: Refer to REMOVAL [10/2022 - ]

Propeller shaft assembly: Refer to REMOVAL [10/2022 - ]
Drive the vehicle and check that no AWD control operation status display graduations are displayed on the multi-display for any wheel.

Check the following methods and set the vehicle in the appropriate condition.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	Propeller Shaft Assembly	-	-
*a	2-wheel Chassis Dynamometer	*b	4-wheel Driven Chassis Dynamometer (Mechanical Front/back Synchronized Type)
*c	4-wheel Driven Chassis Dynamometer (Electric Front/back Synchronized Type)	-	-
	Remove	-	-

NOTE:

Do not suddenly accelerate or apply the brake.

Failure to observe the following methods may cause AWD function effectiveness to decline, drivetrain parts to malfunction or the vehicle to move unexpectedly.

Vehicle Condition	Chassis Dynamometer	Vehicle Speed, Test Time	Propeller Shaft Assembly	4WD ECU Assembly Connector
a (1)	2-wheel Chassis Dynamometer	No limit	Remove	Disconnected
*b	4-wheel Driven Chassis Dynamometer (Mechanical Front/back Synchronized Type)	No limit	Normal	Connected
c (1) (*2)	4-wheel Driven Chassis Dynamometer (Electric Front/back Synchronized Type)	No limit	Remove	Disconnected

NOTE:

(*1): Disconnect the propeller shaft assembly and 4WD ECU assembly connector and perform the test in front wheel drive. If performed under other conditions, the "AWD System Overheated 2WD Mode Engaged" message is displayed on the multi-information display and the drivetrain may be damaged.
(*2): Do not use the electric front/back synchronized type 4-wheel driven chassis dynamometer with the propeller shaft assembly installed since the drivetrain may be damaged. (However, use with the propeller shaft assembly removed is possible)

for 2-wheel Chassis Dynamometer or 4-wheel Driven Chassis Dynamometer (Electric Front/back Synchronized Type):
Connect the propeller shaft assembly and 4WD ECU assembly connector and set the system to the AWD control operation permitted condition.

NOTE:
After measuring, make sure to connect the propeller shaft assembly and 4WD ECU assembly connector.
With the AWD operation status display shown on the multi-display, drive the vehicle and check that 1 or more graduations are displayed for any wheel when accelerating.

CAUTIONS FOR TOWING

Tow the vehicle with all 4 wheels on the ground or lifted up. When towing the vehicle with all 4 wheels on the ground, limit the tow speed to 30 km/h (19 mph) or less and the tow distance to 80 km (50 miles) or less, and tow the vehicle in the forward direction.
NOTE:
If the vehicle is towed above this speed and beyond this distance or is towed in reverse direction, the transaxle may be affected or damaged.

Do not tow with only the front or rear wheels lifted up. If the driving system or drivetrain is malfunctioning, transport the vehicle with all 4 wheels lifted up.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*A	Tow Truck (Rear Wheels on the Ground)	*B	Tow Truck (Front Wheels on the Ground)
*C	Tow Truck (Sling-type)	-	-

NOTE:

Do not use a sling-type towing method. If a sling-type tow truck is used, damage may occur to the vehicle body.
Towing with only the front wheels or rear wheels lifted up may damage drivetrain parts or cause the wheels to jump out of the tow truck.

Use one of the methods shown below to tow the vehicle.

*A	Car Carrier	*B	Tow Truck (4 Wheels Lifted)
*C	Tow Truck (4 Wheels on the Ground) - Limit the tow speed to 30 km/h (19 mph) or less - Limit the tow distance to 80 km (50 miles) or less	-	-

NOTE:

If there is a malfunction in the chassis or drivetrain, use the car carrier.
When towing the vehicle, do not use any towing method other than those shown in the illustration.

PARKING BRAKE AND SHIFT STATE DURING TOWING

Towing Method	Parking Brake	Transmission Shift State
Car Carrier	Parking brake applied*	Any shift state
Tow Truck (4 Wheels Lifted)	Parking brake applied*	Any shift state
Tow Truck (4 Wheels on the Ground)	Parking brake not applied	Shift state N

WARNING:

*: The braking force of the electric parking brake changes according to the tilt of the vehicle. When towing the vehicle, pull the parking brake switch 2 times (2 lock operations) to apply the maximum amount of braking force to prevent the wheels from moving unexpectedly.

HINT:

The steering lock cannot be released with the battery fully depleted or the cable disconnected from the negative (-) battery terminal.