Introduction: Overview Lexus SC II

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1. GENERAL DESCRIPTION This information is made in accordance with SAE J2008. Generally, repair operations can be separated in the following 3 main processes: Diagnosis Removing and Installing, Replacing, Disassembling, Installing and Checking, Adjusting Final Inspection This information explains the 1st process of "Diagnosis" (placed in the "Diagnostics" information ), the 2nd process of "Removing and Installing, Replacing, Disassembling, Installing and Checking, Adjusting", but the 3rd process of "Final Inspection" is omitted. The following essential operations are not written in this information. However, these operations must be done in the practical situation. Operation with a jack or lift Cleaning of a removed part when necessary Visual check
2. PREPARATION Use of special service tools (SST) and special service materials (SSM) may be required, depending on the repairing condition. Be sure to use SST and SSM when they are required and follow the working procedure properly. A list of SST and SSM is in the Preparation information of this article.
3. REPAIR PROCEDURES Component drawing is placed under the title when necessary. Illustrations are placed as "disassembled parts drawing" so that it enables you to understand the fitting condition of the components. Non-reusable parts, grease applied parts, precoated parts and tightening torque are specified in the components drawing. Tightening torque, oil applying position, and non-reusable parts are described as important points in the procedure. NOTE: There are cases where such information can only be indicated by an illustration. In that case, all the information such as torque, oil, etc. are described in the illustration. Installing procedure of operation items is performed in the reverse order of the removal, and only the important points are described. Only items with points are described in the procedure, and the operational portion and content are placed using an illustration. In the explanations, details of the operational method, standard value and notice are placed. There may be a case where the illustrations of the similar models are used. In that case the details may be different from the actual vehicle. The procedures are presented in a step-by-step format: The illustration shows what to do and where to do it. The task heading tells what to do. The detailed text tells how to perform the task and gives other information such as specifications and warnings. Example: HINT: This format provides an experienced technician with a FAST TRACK to the necessary information. The task heading can be read at a glance when necessary, and the text below provides detailed information. Important specifications and warnings always stand out in bold type.
4. SERVICE SPECIFICATIONS Specifications are presented in bold type throughout the information. You never have to leave the procedure to look up your specifications. The specifications are also found in the Service Specifications information for a quick reference.
5. TERMS DEFINITION TERMS DEFINITION CAUTION Indicate the possibility of injury to you or other people. NOTICE Indicate the possibility of damage to the components being repaired. HINT Provide additional information to help you to perform the repair efficiently. The procedures are presented in a step-by-step format
6. SI UNIT The UNITS given in this information 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: Torque: 30 N.m (310 kgf.cm, 22 ft.lbf)

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1. VEHICLE IDENTIFICATION NUMBER The vehicle identification number is stamped on the vehicle identification number plate and the certification label, as shown in the illustration. A: Vehicle Identification Number Plate B: Certification Label
2. ENGINE SERIAL NUMBER AND TRANSMISSION SERIAL NUMBER The engine serial number is stamped on the cylinder block of the engine, and the transmission serial number is stamped on the housing, as shown in the illustration. A: Engine Serial Number B: Transmission Serial Number

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1. BASIC REPAIR HINT HINTS ON OPERATIONS OPERATION HINT 1 Looks Always wear a clean uniform. Hat and safety shoes must be worn. 2 Vehicle protection Set a grill cover, fender cover, seat cover and floor mat before starting the operation. 3 Safe operation In case of working with 2 or more persons, be sure to check safety of one another. When working with the engine running, pay attention to the ventilation of the workshop. In case of operating on high-temperature parts, rotating, moving and vibrating parts, pay attention not to burn or injure yourself. When jacking up the vehicle, be sure to support the specified location with a safety stand. When lifting up the vehicle, apply a safety equipment. 4 Preparation of tools and measuring gauge Before starting operation, prepare a tool stand, SST, gauge, oil, shop rag and parts for replacement. 5 Removal and installation, disassembly and assembly operations Diagnose with a thorough understanding of the trouble phenomenon and perform effective operations. Before removing the parts, check the assembly for general condition, deformation and damage. When the structure is complicated, take a note or put matchmarks so as not to make mistakes that affect the function of the parts. Clean and wash the removed parts if necessary, and assemble them after a thorough check. 6 Removed parts Place the removed parts in the correct order to avoid mixing up or making them dirty. As for non-reusable parts such as gasket, O-ring, and self lock nut, change them to new ones following the instruction of this information. Sort out the parts for replacement in a box and show them to the customer. JACKING UP AND SUPPORTING VEHICLE 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» ). 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 the part with compressed air. Then apply the specified seal lock adhesive to the bolt, nut or threads. NOTE: Perform the torque checking with the lower limit value of the torque tolerance. Depending on the seal lock agent to apply, there may be a case where it is necessary to leave it for a specified time until it hardens. GASKETS When necessary, use a sealer on gaskets to prevent leaks. BOLTS, NUTS AND SCREWS Carefully observe all the specifications for tightening torques. Always use a torque wrench. FUSES When replacing fuses, be sure that a new fuse has the correct amperage rating. DO NOT exceed the rating, or use one with a lower rating. clips The removal and installation methods of typical clips used in body parts are shown in the table below. HINT: If the clip is damaged during the operation, always replace it with a new clip. REMOVAL AND INSTALLATION OF VACUUM HOSES To disconnect vacuum hoses, pull them by holding the end, not the middle of the hose. When disconnecting vacuum hoses, use tags to identify where they should be reconnected. After completing the job, make a double check whether the vacuum hoses are properly connected. A label under the hood shows the proper layout. 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. TORQUE WHEN USING TORQUE WRENCH WITH EXTENSION TOOL In case of tightening by a torque wrench which entire length is extended by the torque wrench combined with SST or extension tool, if you tighten until the reading of the torque wrench reaches the specified torque value, the actual torque becomes excessive. In this text, only the specified torque is described. In case of using SST or extension tool, find the reading of the torque wrench by the following formula. (3)Formula T'=T x L2/(L1 + L2) CODES DESCRIPTIONS T Reading of torque wrench {N.m (kg.fcm, ft.lbf)} T Torque {N.m (kg.fcm, ft.lbf)} L1 Length of SST or extension tool (cm) L2 Length of torque wrench (cm)
2. FOR VEHICLES EQUIPPED WITH SRS AIRBAG AND SEAT BELT PRETENSIONER HINT: The LEXUS SC430 is equipped with an SRS (Supplemental Restraint System), such as the driver airbag, front passenger airbag assembly, side airbag assembly and seat belt pretensioner. Failure to carry out the service operations in the correct sequence could cause the supplemental restraint system to unexpectedly deploy during servicing. It may lead to a serious accident. Furthermore, if a mistake is made in servicing the supplemental restraint system, it is possible that the SRS will 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 procedure described in this information. GENERAL NOTICE Malfunction symptoms of the supplemental restraint system are difficult to be confirmed, so the diagnostic trouble codes become the most important source of information when troubleshooting. When troubleshooting the supplemental restraint system, always check the diagnostic trouble codes before disconnecting the battery (See «RETRIEVING CODES» ). 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 if work is started within 90 seconds after 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 memorized contents in each memory system. Then, when work is finished, reset the clock and audio systems as before. To avoid erasing the memory in each memory system, never use a back-up power supply form another battery. Even in case of a minor collision where the SRS does not deploy, the steering wheel pad, front passenger airbag assembly, front airbag sensor and seat belt pretensioner should be inspected (See «POST-COLLISION INSPECTION» ). Never use the SRS related parts from another vehicle. When replacing the 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, steering wheel pad, front passenger airbag assembly, front airbag sensor or seat belt pretensioner. If the airbag sensor assembly, steering wheel pad, front passenger airbag assembly, front 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, steering wheel pad, front passenger airbag assembly, front 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 an 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 «SYSTEM OPERATION CHECK» ). 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 occur. Refer to «STEERING WHEEL». 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 upward. Placing 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 placed on 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 kinds. 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 airbag 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 SST before disposal (See «DISPOSAL PROCEDURES» ). Perform the operation in a safe place away from electrical noise. FRONT PASSENGER AIRBAG ASSEMBLY Always place a removed or new front passenger airbag assembly with the airbag deployment direction facing upward. Placing the airbag assembly with the airbag deployment direction facing downward 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 airbag 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 SST before disposal (See «DISPOSAL PROCEDURES» ). Perform the operation in a safe place away from electrical noise. SIDE AIRBAG ASSEMBLY Always place a removed or new side airbag assembly with the airbag deployment direction facing upward. Placing the airbag assembly with the airbag deployment direction facing downward 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 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 airbag connector (yellow color and 2 pins) installed on the assembly before starting work. When disposing of a vehicle or the side airbag assembly alone, the airbag should be deployed using SST before disposal (See «DISPOSAL PROCEDURES» ). Perform the operation in a safe place away from electrical noise. 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 PROCEDURES» ). Perform the operation in a safe place away from electrical noise. The seat belt pretensioner is hot after activation, so cool it 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. 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 an 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 loosening the set bolts of the airbag sensor assembly. WIRE HARNESS AND CONNECTOR The SRS wire harness is integrated with the instrument panel wire harness assembly. All the connectors in the system are in 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.
3. ELECTRONIC CONTROL REMOVAL AND INSTALLATION OF BATTERY TERMINAL Before performing electrical work/disconnect the battery negative (-) terminal cable beforehand so as to prevent burnt-out damage by short. When disconnecting and installing the terminal cable, turn the ignition switch and lighting switch OFF, and loosen the terminal nut completely. Perform these operations without twisting or prying the terminal. When the battery terminal is removed, all the memories of the clock, radio, DTCs, etc. will be erased. So before removing it, check them and make a note. HANDLING OF ELECTRONIC 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 electronic connectors, pull the connector itself, not the wires. Be careful not to drop electronic components, such as sensors or relays. If they are dropped on a hard floor, they should be replaced and not reused. When cleaning the engine with steam, 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 the continuity at the wire connector, insert the tester probe carefully to prevent terminals from bending.
4. REMOVAL AND INSTALLATION OF FUEL CONTROL PARTS PLACE FOR REMOVING AND INSTALLING OF FUEL SYSTEM PARTS Place with good air ventilation and without anything flammable such as welder, grinder, drill, electric motor or stove in the surroundings. Never work in a place like a pit or nearby pit, as there is a possibility that Vaporized fuel fills those places. REMOVING AND INSTALLING OF FUEL SYSTEM PARTS Prepare a fire extinguisher before starting the operation. For prevention of the static electricity, install a ground on the fuel changer, vehicle and fuel tank, and do not spray much water so as to prevent slipping. Never use any electric equipment like an electric motor or a working light, as they may cause spark or high temperature. Never use an iron hammer, as it may cause spark. Dispose of the shop rag separately from any fuel deposit.
5. REMOVAL AND INSTALLATION OF ENGINE INTAKE PARTS If any metal tip is mixed in the inlet pass, that may give a bad effect to the engine and turbocharger. When removing and installing the inlet system parts, close the opening of the removed inlet system parts and the engine with a clean shop rag or gummed tape. When installing the inlet system parts, check that there is no mixing of a metal tip.
6. HANDLING OF HOSE CLAMPS Before removing the hose, check the depth of inserting portion and the clamp position in order to restore it surely. Change a deformed or dented clamp into a new one. In case of reusing the hose, install the clamp on the hose where it has a clamp track. For a spring type clamp, adjust it by adding force to the arrow mark direction after the installation.
7. FOR VEHICLES EQUIPPED WITH MOBILE COMMUNICATION SYSTEM Install an antenna as far as possible away from the ECU and sensors of the vehicle's electronic systems. Install an antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the vehicle's electronic systems. For details of the ECU and sensors locations, refer to the information on the applicable component. Prevent the antenna feeder from getting entangled in the other wirings and keep the antenna feeder apart from the other wirings, as much as possible. Check that the antenna and feeder are correctly adjusted. Do not install any powerful mobile communication system.
8. 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 OFF switch and turn the TRAC & VSC system OFF. Press the VSC OFF switch. Check that the VSC OFF indicator light comes ON. HINT: The VSC OFF indicator light should be always OFF when the engine is restarted. Start measurements. Press the VSC OFF switch again to change the TRAC & VSC system into operational condition and check that the VSC OFF indicator light goes off. HINT: The SLIP indicator light blinks when the TRAC system is operational.
9. FOR VEHICLES EQUIPPED WITH CATALYTIC CONVERTER CAUTION: If large amount of unburned gasoline flows into the converter, it may cause overheating and a fire hazard. To prevent this, observe the following precautions and explain them to your customer. Use only unleaded gasoline. Avoid prolonged idling. Avoid running the engine at idle speed for more than 20 minutes. Avoid a spark jump test. Perform a spark jump test only when absolutely necessary. Perform this test as rapidly as possible. While testing, never race the engine. Avoid a prolonged engine compression measurement. Engine compression measurements must be performed as rapidly as possible. 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.
10. INSPECTION AND ADJUSTMENT OF JOINT ANGLE DURING REMOVAL AND INSTALLATION OF PROPELLER SHAFT When performing operations which involve the removal and installation of the propeller shaft, always check the joint angle. Make adjustments if necessary (See «OVERHAUL»(/lexus/sc/ii-2001-2005/remont/driveshaft-universal-joints/#driveshaft-wcenter-bearing) ).

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1. NOTICE ABOUT VEHICLE CONDITION WHEN JACKING UP As a rule, vehicle must be unloaded and never jack up or lift up the vehicle with things of heavy weight. If removing any things of heavy weight like the engine and transmission, the center of gravity of the vehicle moves. Therefore, place a balance weight so as to keep it from rolling, or hold the jacking support location using the mission jack.
2. NOTICE FOR USING 4 POST LIFT Follow the instruction information for a safety operation. Do not damage tires or wheels with a free wheel beam. Using a wheel stopper, fix the vehicle.
3. NOTICE FOR USING JACK AND RIGID RACK Operate in the flat place using a wheel stopper all the time. Use a rigid rack with a rubber attachment, as shown in the illustration. Support the specified location of the jack and rigid rack accurately. When jacking up the front wheels, release the parking brake and place wheel stoppers only behind the rear wheels. When jacking up the rear wheels, place wheel stoppers only in front of the front wheels. Do not work or leave the vehicle supported only by jack. Be sure to support the vehicle together with a rigid rack. When jacking up only the front wheels or only the rear wheels, place wheel stoppers both in front of and behind the wheels that contact ground. When jacking down the vehicle which front wheels are jacked up, release the parking brake and place wheel stoppers only in front of the rear wheels. When jacking down vehicle which rear wheels are jacked up, place wheel stoppers only behind the front wheels.
4. NOTICE FOR USING PLATE TYPE LIFT Follow the instruction information of the lift for a safe operation. Use a plate lift attachment. Be sure to drive in the vehicle to the specified position. LIFT POSITION Right and left set position Place the vehicle over the center of the lift. Front and rear set position Align the cushion gum ends of the plate with the attachment lower ends (A and C). Align the attachment upper end (B) with the front jack supporting point (L). Lift the vehicle up until the tires float a bit, and shake the vehicle to make sure that the vehicle is stable.

GENERAL INFORMATION

A large number of ECU controlled systems are used in the LEXUS SC430. In general, the ECU controlled system is considered to be a very intricate system requiring high level of technical knowledge and expert skill to troubleshoot. The fact is, however, that if you proceed to inspect the circuit inspections one by one, troubleshooting of these systems is not complex. If you have adequate understanding of the system and basic knowledge of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. This information is designed through emphasis of the above standpoint to help service technicians perform an accurate and effective troubleshooting, and is compiled for the following major ECU controlled systems.

The troubleshooting procedures and how to make use of it are described on the following

SYSTEM INDEX

FOR USING SCAN TOOL OR HAND-HELD TESTER

1. Before using the tester, the tester's operator information should be read thoroughly.
2. If the tester cannot communicate with the ECU controlled systems when you have connected the cable of the tester to the DLC3, turned the ignition switch ON and operated the tester, there is a problem on the vehicle side or tester side. If the communication is normal when the tester is connected to another vehicle, inspect the diagnosis data link line (Bus (+) line) or ECU power circuit of the vehicle. If the communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself, so perform the Self Test procedures outlined in the Tester Operator's information .

ABBREVIATIONS USED IN THIS INFORMATION

ABBREVIATIONS MEANING

See also:
• OVERHAUL
• ABS WITH EBD & BA & TRAC & VSC SYSTEM - DIAGNOSIS
• POWER TILT AND POWER TELESCOPING STEERING COLUMN
• PROGRESSIVE POWER STEERING SYSTEM - DIAGNOSIS
• AIR CONDITIONING SYSTEM - DIAGNOSIS
• LEXUS NAVIGATION SYSTEM - DIAGNOSIS
• COMBINATION METER - DIAGNOSIS