Part 2
INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION
3. ELECTRONIC CONTROL
(a) REMOVAL AND INSTALLATION OF BATTERY TERMINAL
NOTICE:
Certain systems need to be initialized after disconnecting and reconnecting the cable from the negative (-) battery terminal.
(1) Before performing electronic work, disconnect the cable from the negative (-) battery terminal to prevent component and wire damage caused by accidental short circuits.
(2) When disconnecting the cable, turn the engine switch OFF and headlight dimmer switch OFF and loosen the cable nut completely. Perform these operations without twisting or prying the cable. Then disconnect the cable.
(3) Clock settings, radio settings, audio system memory, DTCs and other data are erased when the cable is disconnected from the negative (-) battery terminal. Write down any necessary data before disconnecting the cable.
(b) HANDLING OF ELECTRONIC PARTS
(1) Do not open the cover or case of the ECU unless absolutely necessary. If the IC terminals are touched, the IC may be rendered inoperative by static electricity.
(2) Do not pull the wires when disconnecting electronic connectors. Pull the connector itself.
(3) Be careful not to drop electronic components, such as sensors or relays. If they are dropped on a hard surface, they should be replaced.
(4) When cleaning the engine with steam, protect the electronic components, air filter and emission-related components from water.
(5) Never use an impact wrench to remove or install temperature switches or temperature sensors.
(6) When measuring the resistance of a wire connector, insert the tester probe carefully to prevent terminals from bending.
4. REMOVAL AND INSTALLATION OF FUEL CONTROL PARTS
(a) PLACE FOR REMOVING AND INSTALLING FUEL SYSTEM PARTS
(1) Work in a location with good air ventilation that does not have welders, grinders, drills, electric motors, stoves, or any other engine sources.
(2) Never work in a pit or near a pit as vaporized fuel will collect in those places.
(b) REMOVING AND INSTALLING FUEL SYSTEM PARTS
(1) Prepare a fire extinguisher before starting the operation.
(2) To prevent static electricity, install a ground wire to the fuel changer, vehicle and fuel tank, and do not spray the surrounding area with water. Be careful when performing work in this area, as the work surface will become slippery. Do not clean up gasoline spills with water, as this may cause the gasoline to spread, and possibly create a fire hazard.
(3) Avoid using electric motors, working lights and other electric equipment that can cause sparks or high temperatures.
(4) Avoid using iron hammers as they may create sparks.
(5) Dispose of fuel-contaminated cloth separately using a fire resistant container.
5. REMOVAL AND INSTALLATION OF ENGINE INTAKE PARTS
(a) If any metal particles enter inlet system parts, this may damage the engine.
(b) When removing and installing inlet system parts, cover the openings of the removed parts and engine openings. Use gummed tape or other suitable materials.
(c) When installing inlet system parts, check that no metal particles have entered the engine or the installed parts.
6. HANDLING OF HOSE CLAMPS
(a) Before removing the hose, check the clamp position so that it can be reinstalled in the same position.
(b) Replace any deformed or dented clamps with new ones.
(c) When reusing a hose, attach the clamp on the clamp track portion of the hose.
(d) For a spring type clamp, you may want to spread the tabs slightly after installation by pushing in the direction of the arrows as shown in the illustration.
7. FOR VEHICLES EQUIPPED WITH MOBILE COMMUNICATION SYSTEMS
(a) Install the antenna as far away from the ECU and sensors of the vehicle electronic systems as possible.
(b) Install an antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the vehicle electronic systems. For details about ECU and sensor locations, refer to the section of the applicable components.
(c) Keep the antenna and feeder separate from other wirings as much as possible. This will prevent signals from the communication equipment from affecting vehicle equipment and vice versa.
(d) Check that the antenna and feeder are correctly adjusted.
(e) Do not install any high-powered mobile communication system.
8. HEADLIGHT INSPECTION MAINTENANCE
(a) When the headlight dimmer switch assembly is set to HEAD, do not touch the discharge headlight's high-voltage socket area.
NOTICE:
When performing inspection maintenance, the discharge headlight's precautions must be followed.
(b) When the headlights are illuminated, do not cover the headlights for 3 minutes or more.
NOTICE:
As the headlight's outer lens is made of resin, the resulting heat created when covering the headlight for an extended period of time may deform the headlight.
9. FOR VEHICLES EQUIPPED WITH TR(A)C (TRACTION CONTROL) SYSTEM AND VSC (VEHICLE STABILITY CONTROL) SYSTEM
(a) NOTICES FOR WHEN TESTING WITH 2-WHEEL DRUM TESTER
(1) When testing with a 2-wheel drum tester such as a speedometer tester, a combination tester for the speedometer and brake, a chassis dynamometer, enter maintenance mode, or switch to VSC OFF mode to turn TR(A)C and VSC operation off. Then enter test mode, start the engine and perform measurements.
CAUTION:
* If the vehicle is tested in normal mode on the drum tester, TR(A)C and VSC operation may cause the vehicle to jump out from the drum tester.
* When switching to VSC OFF mode, the VSC OFF switch must be held for 3 seconds or more with the vehicle stopped. TR(A)C and VSC operation must both be turned off before beginning testing.
* During VSC off mode, the VSC OFF indicator light will come on and the TR(A)C OFF message will be displayed on the multi information display.
* Fix the vehicle in place with chains for safety.
(b) NOTICES FOR VSC RELATED PROCEDURES
(1) For VSC related parts, adjustments are required after removal and installation. Therefore, perform removal and installation only when necessary.
(2) When performing VSC related procedures, be sure to strictly follow the preparation and completion procedures.
(3) When performing removal and installation or replacement of VSC related parts, first disconnect the cable from the negative (-) battery terminal.
10. WHEN SERVICING FULL-TIME AWD VEHICLES
(a) The full-time AWD LEXUS GS350 is equipped with the All-Wheel-Drive control system.
If incorrect preparations or test procedures are used, the test will not only be unsuccessful, but may be dangerous as well.
Therefore, before beginning any such servicing or test, be sure to check the following items:
(1) Whether the tires are touching the ground or jacked up
(2) Transmission gear position
(3) Maximum testing vehicle speed
(4) Maximum testing time
CAUTION:
* Never accelerate or decelerate the vehicle suddenly
* Observe the other cautions given for each individual test.
(b) When using a braking force tester (not free roller type):
When performing measurements using a low-speed type brake tester, observe the following instructions.
To disable the AWD system, short terminals OPA and CG of the DLC3.
(2) If the vehicle is equipped with the Vehicle Stability Control (VSC) & Traction Control (TR(A)C) system, prohibit the system from activating.
Position the rear wheels to be tested on the tester.
(4) Position the front wheels between wheel chocks, or jack up the front wheels.
(5) Shift the transmission shift lever to the "N" position.
(6) Idle the engine, operate the brake booster and perform the test.
(c) When using a braking force tester (free roller type):
When performing measurements using a low-speed type brake tester, observe the following instructions.
(1) Enter inspection mode to disable TR(A)C and VSC control.
(2) Position the rear wheels on the tester roller.
(3) Position the front wheels on the free roller.
CAUTION:
The maximum speed should be less than 60 km/h (37 mph) and maximum driving time should be 1 minute.
HINT
* Sudden shifting, braking, acceleration or deceleration is not allowed.
* Make sure to activate the Vehicle Stability Control (VSC) & Traction Control (TR(A)C) system to operational condition after the test. Check that the slip indicator light goes off when restarting the engine.
(d) When using a speedometer (not free roller type):
Observe the following instructions and then measure with the rear wheels.
To disable the AWD system, short terminals OPA and CG of the DLC3.
(2) Enter inspection mode to disable TR(A)C and VSC control.
Position the rear wheels on the tester.
(4) Position the front wheels between wheel chocks, or jack up the front wheels.
(5) Ensure that the vehicle does not move using wires.
(6) Shift the transmission shift lever to the "N" position.
(7) Idle the engine, operate the brake booster and perform the test.
(e) When using a speedometer (free roller type):
Observe the following instructions and then measure with the rear wheels.
Position the rear wheels on the tester roller.
(2) Position the front wheels on the free roller.
(3) Enter inspection mode to disable TR(A)C and VSC control.
(4) Ensure that the vehicle does not move using wires.
CAUTION:
The maximum speed should be less than 60 km/h (37 mph) and maximum driving time should be 1 minute.
HINT
* Sudden shifting, braking, acceleration or deceleration is not allowed.
* Make sure to activate the Vehicle Stability Control (VSC) & Traction Control (TR(A)C) system after the test. Check that the slip indicator light goes off when restarting the engine.
(f) Using chassis dynamometer
Observe the following instructions and then measure with the rear wheels.
(1) Enter inspection mode to disable TR(A)C and VSC control.
(2) Ensure that the vehicle is securely fixed.
HINT
* Sudden shifting, braking, acceleration or deceleration is not allowed.
* Make sure to activate the Vehicle Stability Control (VSC) & Traction Control (TR(A)C) system after the test. Check that the slip indicator light goes off when restarting the engine.
(g) On-vehicle wheel balancing
NOTICE:
Do not use on-vehicle wheel balancing.
11. WHEN TOWING FULL-TIME AWD VEHICLES
Using one of the methods shown below to tow the vehicle.
If the vehicle has trouble in the chassis and drive train, use method 1 (flat bed truck).
NOTICE:
Do not use any towing method other than those shown above.
For example, the towing methods shown below are dangerous or damage the vehicle, so do not use them.
12. FOR VEHICLES EQUIPPED WITH CATALYTIC CONVERTER
CAUTION:
If a large amount of unburned gasoline or gasoline vapors flow into the converter, it may cause overheating and create a fire hazard. To prevent this, observe the following precautions.
(a) Use only unleaded gasoline.
(b) Avoid idling the engine for more than 20 minutes.
(c) Avoid performing unnecessary spark jump tests.
(1) Perform a spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid a prolonged engine compression measurement. Engine compression measurements must be performed as rapidly as possible.
(e) Do not run the engine when the fuel tank is nearly empty. This may cause the engine to misfire and create an extra load on the converter.
13. INSPECTION AND ADJUSTMENT OF JOINT ANGLE DURING REMOVAL AND INSTALLATION OF PROPELLER SHAFT
(a) When performing operations which involve the removal and installation of the propeller shaft, always check the joint angle. Make adjustments if necessary.
