Introduction: Other Lexus GS III

INDEX

To assist you in finding your way through these articles, the task heading are given at the top of each procedure.

PRECAUTION

At the beginning of each article, a PRECAUTION is given that pertains to all repair operations contained in that article.

Read these precautions before starting any repair task.

PREPARATION

Preparation lists the SST (Special Service Tools), recommended tools, equipment, lubricant and SSM (Special Service Materials) which should be prepared before beginning the operation and explains the purpose of each one.

REPAIR PROCEDURES

Most repair operations begin with an overview illustration. It identifies the components and shows how the parts fit together.

Example

Scheme 34

The procedures are presented in a step-by-step format

1. The illustration shows what to do and where to do it.
2. The task heading tells what to do.
3. The detailed text tells how to perform the task and gives other information such as specifications and warnings.

Example

Scheme 35

This format provides the experienced technician with a FAST TRACK to the information needed. The upper case task heading can be read at a glance when necessary, and the text below it provides detailed information. Important specifications and warnings always stand out in bold type.

REFERENCES

References have been kept to a minimum. However, when they are required you are given the article to refer to.

CAUTIONS, NOTICES, HINTS

1. CAUTIONS are presented in bold type, and indicate there is a possibility of injury to you or other people.
2. NOTICES are also presented in bold type, and indicate the possibility of damage to the components being repaired.
3. HINTS are separated from the text but do not appear in bold. They provide additional information to help you perform the repair efficiently.

SI UNIT

The UNITS given in this article are primarily expressed according to the SI UNIT (International System of Unit), and alternately expressed in the metric system and in the English System.

Example

1. Torque: 30 N.m (310 kgf.cm, 22 ft.lbf)

ENGINE SERIAL NUMBER

The engine serial number is stamped on the engine block, as shown in the illustration.

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1. Use fender, seat and floor covers to keep the vehicle clean and prevent damage.
2. During disassembly, keep parts in the appropriate order to facilitate reassembly.
3. Installation and removal of battery terminal: Before performing electrical work, disconnect the negative (-) terminal cable from the battery. If it is necessary to disconnect the battery for inspection or repair, first disconnect the negative (-) terminal cable. When disconnecting the terminal cable, to prevent damage to the battery terminal, loosen the cable nut and raise the cable straight up without twisting or prying it. Clean the battery terminals and cable ends with a clean shop rag. Do not scrape them with a file or other abrasive objects. Install the cable ends to the battery terminals after loosening the nut, and tighten the nut after installation. Do not use a hammer to tap the cable ends onto the terminals. Be sure the cover for the positive (+) terminal is properly in place.
4. Check hose and wiring connectors to make sure that they are connected securely and correctly.
5. Non-reusable parts Always replace cotter pins, gaskets, O-rings, oil seals, etc. with new ones. Non-reusable parts are indicated in the component illustrations by the "DIAMOND" symbol.
6. Precoated parts Precoated parts are bolts, nuts, etc. that are coated with a seal lock adhesive at the factory. If a precoated part is retightened, loosened or caused to move in any way, it must be recoated with the specified adhesive. When reusing precoated parts, clean off the old adhesive and dry with compressed air. Then apply the specified seal lock adhesive to the bolt, nut or threads. Precoated parts are indicated in the component illustrations by the "*" symbol.
7. When necessary, use a sealer on gaskets to prevent leaks.
8. Carefully observe all specifications for bolt tightening torques. Always use a torque wrench.
9. Use of special service tools (SST) and special service materials (SSM) may be required, depending on the nature of the repair. Be sure to use SST and SSM where specified and follow the proper work procedure.
10. When replacing fuses, be sure the new fuse has the correct amperage rating. DO NOT exceed the rating or use one with a lower rating.
11. Care must be taken when jacking up and supporting the vehicle. Be sure to lift and support the vehicle at the proper locations (See «VEHICLE LIFT AND SUPPORT LOCATIONS»(ref-229346-S22204211892006041400000) ). Cancel the parking brake on the level place and shift the transmission in Neutral (or N position). When jacking up the front wheels of the vehicle, at first place stoppers behind the rear wheels. When jacking up the rear wheels of the vehicle, at first place stoppers before the front wheels. When either the front or rear wheels only should be jacked up, set rigid racks and place stoppers in front and behind the other wheels on the ground. After the vehicle is jacked up, be sure to support it on rigid racks. It is extremely dangerous to do any work on a vehicle raised on a jack alone, even for a small job that can be finished quickly.
12. Observe the following precautions to avoid damage to the following parts: Do not open the cover or case of the ECU unless absolutely necessary (If the IC terminals are touched, the IC may be destroyed by static electricity). To disconnect vacuum hoses, pull off the end, not the middle of the hose. To pull apart electrical connectors, pull on the connector itself, not the wires. Be careful not to drop electrical components, such as sensors or relays. If they are dropped on a hard floor, they should be replaced and not reused. When steam cleaning an engine, protect the electronic components, air filter and emission-related components from water. Never use an impact wrench to remove or install temperature switches or temperature sensors. When checking continuity at the wire connector, insert the tester probe carefully to prevent terminals from bending. When using a vacuum gauge, never force the hose onto a connector that is too large. Use a step-down adapter for adjustment. Once the hose has been stretched, it may leak air.
13. Installation and removal of vacuum hose: When disconnecting vacuum hoses, use tags to identify where they should be reconnected to. After completing a job, double check that the vacuum hoses are properly connected. A label under the hood shows the proper layout.
14. Bleeding of hydraulic brake booster: When repairing the hydraulic brake booster or ABS, TRAC and VSC system, bleeding the air out of the hydraulic brake booster (See «BRAKE FLUID»(ref-229381-S16644914782006041500000) ).
15. Unless otherwise stated, all resistance is measured at an ambient temperature of 20°C (68°F). Because the resistance may be outside specifications if measured at high temperatures immediately after the vehicle has been running, measurement should be made when the engine has cooled down.

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1. The LEXUS GS300/GS4300 is equipped with an SRS (Supplemental Restraint System), such as the driver air-bag, front passenger airbag assembly, side airbag assembly, curtain shield airbag and seat belt pretensioner. Failure to carry out service operations in the correct sequence could cause the supplemental restraint system to unexpectedly deploy during servicing, possibly leading to a serious accident. Further, if a mistake is made in servicing the supplemental restraint system, it is possible the SRS may fail to operate when required. Before servicing (including removal or installation of parts, inspection or replacement), be sure to read the following items carefully, then follow the correct procedures as described.
2. GENERAL NOTICE Malfunction symptoms of the supplemental restraint system are difficult to confirm, so the diagnostic trouble codes become the most important source of information when troubleshooting. When troubleshooting the supplemental restraint system, always inspect the diagnostic trouble codes before disconnecting the battery (See «PRE-CHECK»(ref-229355-S07012785592006041400000) ). Work must be started after 90 seconds from the time the ignition switch is turned to the "LOCK" position and the negative (-) terminal cable is disconnected from the battery (The supplemental restraint system is equipped with a back-up power source so that if work is started within 90 seconds of disconnecting the negative (-) terminal cable from the battery, the SRS may deploy). When the negative (-) terminal cable is disconnected from the battery, memory of the clock and audio systems will be cancelled. So before starting work, make a record of the contents memorized by the each memory system. Then when work is finished, reset the clock and audio systems as before. This vehicle has power tilt and power telescopic steering, power seat and power outside rear view mirror, which are all equipped with memory function, it is not possible to make a record of the memory contents. So when the work is finished, therefore it will be necessary to explain this fact to the customer, and ask the customer to adjust the features and reset the memory. To avoid erasing the memory of each memory system, never use a back-up power supply from another battery. Even in cases of a minor collision where the SRS does not deploy, the steering wheel pad, front passenger airbag assembly, side airbag assembly, front airbag sensor, side airbag sensor and seat belt pretensioner should be inspected: See «INSPECTION»(ref-229383-S13383101132006041500000) under STEERING WHEEL PAD AND SPIRAL CABLE. See «INSPECTION»(ref-229383-S24960282312006041500000) under FRONT PASSENGER AIRBAG ASSEMBLY. See «INSPECTION»(ref-229383-S00518419292006041500000) under SIDE AIRBAG ASSEMBLY. See «INSPECTION»(ref-229383-S11933943912006041500000) under FRONT AIRBAG SENSOR. See «INSPECTION»(ref-229383-S20617605982006041500000) under SIDE AND CURTAIN SHIELD AIRBAG SENSOR ASSEMBLY. See «INSPECTION»(ref-229443-S12654845542006041500000) under SEAT BELT PRETENSIONER. Never use SRS parts from another vehicle. When replacing parts, replace them with new parts. Before repairs, remove the airbag sensor if shocks are likely to be applied to the sensor during repairs. Never disassemble and repair the airbag sensor assembly, side airbag sensor assembly, steering wheel pad, front passenger airbag assembly, side airbag assembly, front airbag sensor, side airbag sensor or seat belt pretensioner. If the airbag sensor assembly, side airbag sensor assembly, steering wheel pad, front passenger air-bag assembly, side airbag assembly, front airbag sensor, side airbag sensor or seat belt pretensioner has been dropped, or if there are cracks, dents or other defects in the case, bracket or connector, replace them with new ones. Do not directly expose the airbag sensor assembly, side airbag sensor assembly, steering wheel pad, front passenger airbag assembly, side airbag assembly, front airbag sensor, side airbag sensor or seat belt pretensioner to hot air or flames. Use a volt/ohmmeter with high impedance (10 kohm/V minimum) for troubleshooting of the electrical circuit. Information labels are attached to the periphery of the SRS components. Follow the instructions on the notices. After work on the supplemental restraint system is completed, check the SRS warning light (See «PRE-CHECK»(ref-229355-S07012785592006041400000) ).
3. SPIRAL CABLE (in Combination Switch) The steering wheel must be fitted correctly to the steering column with the spiral cable at the neutral position, otherwise cable disconnection and other troubles may result. Refer to «INSTALLATION»(ref-229382-S28784518512006041500000) concerning correct steering wheel installation.
4. STEERING WHEEL PAD (with Airbag) When removing the steering wheel pad or handling a new steering wheel pad, it should be placed with the pad top surface facing up. Storing the pad with its metallic surface facing upward may lead to a serious accident if the airbag deploys for some reason. In addition do not store a steering wheel pad on top of another one. Never measure the resistance of the airbag squib (This may cause the airbag to deploy, which is very dangerous). Grease should not be applied to the steering wheel pad and the pad should not be cleaned with detergents of any kind. Store the steering wheel pad where the ambient temperature remains below 93°C (200°F), without high humidity and away from electrical noise. When using electric welding, first disconnect the air-bag connector (yellow color and 2 pins) under the steering column near the combination switch connector before starting work. When disposing of a vehicle or the steering wheel pad alone, the airbag should be deployed using an SST before disposal (See «DISPOSAL»(ref-229383-S22078629392006041500000) ). Carry out the operation in a safe place away from electrical noise.
5. FRONT PASSENGER AIRBAG ASSEMBLY Always store a removed or new front passenger air-bag assembly with the airbag deployment direction facing up. Storing the airbag assembly with the airbag deployment direction facing down could cause a serious accident if the airbag deploys. Never measure the resistance of the airbag squib (This may cause the airbag to deploy, which is very dangerous). Grease should not be applied to the front passenger airbag assembly and the airbag door should not be cleaned with detergents of any kind. Store the airbag assembly where the ambient temperature remains below 93°C (200°F), without high humidity and away from electrical noise. When using electric welding, first disconnect the air-bag connector (yellow color and 2 pins) installed on the assembly before starting work. When disposing of a vehicle or the airbag assembly alone, the airbag should be deployed using an SST before disposal (See «DISPOSAL»(ref-229383-S18645301182006041500000) ). Perform the operation in a safe place away from electrical noise.
6. SIDE AIRBAG ASSEMBLY Always store a removed or new side airbag assembly with the airbag deployment direction facing up. Storing the airbag assembly with the airbag deployment direction facing down could cause a serious accident if the airbag deploys. Never measure the resistance of the airbag squib (This may cause the airbag to deploy, which is very dangerous). Grease should not be applied to the side airbag assembly and the surface should not be cleaned with detergents of any kind. Store the airbag assembly where the ambient temperature remains below 93°C (200°F), without high humidity and away from electrical noise. When using electric welding, first disconnect the air-bag connector (yellow color and 2 pins) under the seat before starting work. When disposing of a vehicle or the side airbag assembly alone, the airbag should be deployed using an SST before disposal (See «DISPOSAL»(ref-229383-S31484289312006041500000) ). Perform the operation in a safe place away from electrical noise.
7. CURTAIN SHIELD AIRBAG ASSEMBLY Always store a removed or new curtain shield air-bag assembly in a clear plastic bag, and keep it in a safe place. NOTE: Clear plastic bag is not reuse. CAUTION: Never disassemble the curtain shield airbag assembly. Never measure the resistance of the airbag squib (This may cause the airbag to deploy, which is very dangerous). Grease should not be attached to the curtain shield airbag assembly and the surface should not be cleaned with detergents of any kind. Store the airbag assembly where the ambient temperature remains below 93°C (200°F), without high humidity and away from electrical noise. When using electric welding, first disconnect the air-bag connector (yellow color and 2 pins) into the instrument panel before starting work. When disposing of a vehicle or the curtain shield air-bag assembly alone, the airbag should be deployed using an SST before disposal (See «DISPOSAL»(ref-229383-S05812690092006041500000) ). Perform the operation in a safe place away from electrical noise.
8. SEAT BELT PRETENSIONER Never measure the resistance of the seat belt pretensioner. (This may cause the seat belt pretensioner to activate, which is very dangerous.) Never disassemble the seat belt pretensioner. Never install the seat belt pretensioner in another vehicle. Store the seat belt pretensioner where the ambient temperature remains below 80°C (176°F) and away from electrical noise without high humidity. When using electric welding, first disconnect the connector (yellow color and 2 pins) before starting work. When disposing of a vehicle or the seat belt pretensioner alone, the seat belt pretensioner should be activated before disposal (See «DISPOSAL»(ref-229443-S18698416672006041500000) ). Perform the operation in a safe place away from electrical noise. The seat belt pretensioner is hot after activation, so let it cool down sufficiently before the disposal. However never apply water to the seat belt pretensioner. Oil or water should not be put on the front seat outer belt and the front seat outer belt should not be cleaned with detergents of any kind.
9. AIRBAG SENSOR ASSEMBLY Never reuse the airbag sensor assembly involved in a collision when the SRS has deployed. The connectors to the airbag sensor assembly should be connected or disconnected with the sensor mounted on the floor. If the connectors are connected or disconnected while the airbag sensor assembly is not mounted to the floor, it could cause undesired ignition of the supplemental restraint system. Work must be started after 90 seconds from the time the ignition switch is turned to the "LOCK" position and the negative (-) terminal cable is disconnected from the battery, even if only loosing the set bolts of the airbag sensor assembly.
10. WIRE HARNESS AND CONNECTOR The SRS wire harness is integrated with the instrument panel wire harness assembly. All the connectors in the system are a standard yellow color. If the SRS wire harness becomes disconnected or the connector becomes broken due to an accident, etc., repair or replace it as necessary, refer to «WIRE HARNESS AND CONNECTOR»(ref-229383-S38348873432006041500000)

FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER

1. Use only unleaded gasoline.
2. Avoid prolonged idling. Avoid running the engine at idle speed for more than 20 minutes.
3. Avoid spark jump test. Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible. While testing, never race the engine.
4. Avoid prolonged engine compression measurement. Engine compression tests must be done as rapidly as possible.
5. Do not run engine when fuel tank is nearly empty. This may cause the engine to misfire and create an extra load on the converter.
6. Avoid coasting with ignition turned off.
7. Do not dispose of used catalyst along with parts contaminated with gasoline or oil.

IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM

For vehicles with mobile communication systems such as two-way radios and cellular telephones, observe the following precautions.

1. Install the antenna as far as possible away from the ECU and sensors of the vehicle's electronic system.
2. Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the vehicle's electronic systems. For details about ECU and sensors locations, refer to the applicable component. (See «ELECTRICAL COMPONENT LOCATOR»(ref-179371) ).
3. Avoid winding the antenna feeder together with other wiring as much as possible, and also avoid running the antenna feeder parallel with other wire harnesses.
4. Check that the antenna and feeder are correctly adjusted.
5. Do not install powerful mobile communications system.

FOR VEHICLES EQUIPPED WITH VEHICLE SKID CONTROL (VSC) SYSTEM

Note. When using a 2-wheel drum tester such as a speedometer tester or chassis dynamometer, etc., or jacking up the rear wheels and driving the wheels, always push in the TRAC & VSC cut switch and turn the TRAC & VSC system OFF.

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1. Press the VSC OFF switch.
2. Check that the VSC OFF indicator light comes ON. HINT: The VSC OFF indicator light should be always OFF when the engine is restarted.
3. Begin measurements.
4. Press the VSC OFF switch again to change the TRAC & VSC system to operational condition and check that the VSC OFF indicator light goes off. HINT: The SLIP indicator light blinks when the TRAC system is operational.

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GLOSSARY OF SAE AND LEXUS TERMS

This glossary lists all SAE-J1930 terms and abbreviations used in the GS300/GS430 articles are in compliance with SAE recommendations, as well as their LEXUS equivalents.

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