Introduction: Overview Lexus SC II рестайлинг

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1. GENERAL DESCRIPTION This article is written in accordance with SAE J2008. Diagnosis Removing / Installing, Replacing, Disassembling / Reassembling, Checking and Adjusting Final Inspection The following procedures are omitted from this article. However, these procedures must be performed. Use a jack or lift to perform operations. Clean all removed parts. Perform a visual check.
2. INDEX An alphabetical INDEX section is provided at the end of the article as a reference to help you find the item to be repaired.
3. PREPARATION Use of Special Service Tools (SST) and Special Service Materials (SSM) may be required, depending on the repair procedure. Be sure to use SST and SSM when they are required and follow the working procedures properly. A list of SST and SSM is in the "Preparation" section of this article.
4. REPAIR PROCEDURES A component illustration is placed under the title where necessary. Non-reusable parts, grease application areas, precoated parts and torque specifications are noted in the component illustrations. The following illustration is an example. (Scheme 1): Exploded View Of Master Cylinder With Torque Specifications Torque specifications, grease application areas and non-reusable parts are emphasized in the procedures. HINT: There are cases where such information can only be explained by using an illustration. In these cases, torque, oil and other information are described in the illustration. Only items with key points are described in the text. What to do and other details are explained using illustrations next to the text. Both the text and illustrations are accompanied by standard values and notices. ILLUSTRATION CHART Illustration What to do and where to do it Task heading What work will be performed Explanation text How to perform the task Information such as specifications and warnings, which are written in boldface text Illustrations of similar vehicle models are sometimes used. In these cases, minor details may be different from the actual vehicle. Procedures are presented in a step-by-step format.
5. SERVICE SPECIFICATIONS SPECIFICATIONS are presented in boldface text throughout the article. The specifications are also found in the "Service Specifications" section for reference.
6. TERM DEFINITIONS TERM DEFINITIONS CAUTION Possibility of injury to you or other people. NOTICE Possibility of damage to components being repaired. HINT Provides additional information to help you perform repairs.
7. INTERNATIONAL SYSTEM OF UNITS The units used in this article comply with the International System of Units (SI) standard. Units from the metric system and English system are also provided. Example: Torque: 30 N*m (310 kgf*cm, 22 ft.*lbf)

Identifying Vehicle Identification And Serial Numbers. Scheme 2

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1. VEHICLE IDENTIFICATION NUMBER The vehicle identification number is stamped on the vehicle identification number plate and on the certification label, as shown in the illustration. Vehicle Identification Number Plate 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 illustrations. Engine Serial Number (Scheme 3): Identifying Engine Serial Number Transmission Serial Number (Scheme 4): Identifying Transmission Serial Number

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1. BASIC REPAIR HINT HINTS ON OPERATIONS (Scheme 5): Precaution - Hints On Operations VEHICLE PROTECTION DESCRIPTION CHART 1 Attire Always wear a clean uniform. A hat and safety shoes must be worn. 2 Vehicle protection Prepare a grille cover, fender cover, seat cover and floor mat before starting the operation. 3 Safe operation When working with 2 or more persons, be sure to check safety for one another. When working with the engine running, make sure to provide ventilation for exhaust fumes in the workshop. If working on high temperature, high pressure, rotating, moving, or vibrating parts, wear appropriate safety equipment and take extra care not to injure yourself or others. When jacking up the vehicle, be sure to support the specified location with a safety stand. When lifting up the vehicle, use appropriate safety equipment. 4 Preparation of tools and measuring gauge Before starting the operation, prepare a tool stand, SST, gauge, oil and parts for replacement. 5 Removal and installation, disassembly and assembly operations Diagnose with a thorough understanding of proper procedures and of the reported problem. Before removing parts, check the general condition of the assembly and for deformation and damage. When the assembly is complicated, take notes. For example, note the total number of electrical connections, bolts, or hoses removed. Add matchmarks to ensure reassembly of components to their original positions. Temporarily mark hoses and their fittings if needed. Clean and wash the removed parts if necessary and assemble them after a thorough check. 6 Removed parts Place removed parts in a separate box to avoid mixing them up with new parts or contaminating new parts. For non-reusable parts such as gaskets, O-rings, and self-locking nuts, replace them with new ones as instructed in this manual. Retain the removed parts for customer inspection, if requested. 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. PRECOATED PARTS Precoated parts are bolts and nuts that are coated with a seal lock adhesive at the factory. If a precoated part is retightened, loosened or moved in any way, it must be recoated with the specified adhesive. When reusing a precoated part, clean off the old adhesive and dry the part with compressed air. Then apply new seal lock adhesive appropriate to that part. (Scheme 6): Identifying Seal Lock Adhesive On Bolts Some seal lock agents harden slowly. You may have to wait for the seal lock adhesive to harden. GASKETS When necessary, use a sealer on gaskets to prevent leaks. BOLTS, NUTS AND SCREWS Carefully follow all the specifications for tightening torques. Always use a torque wrench. FUSES When inspecting a fuse, check that the wire of the fuse is not broken. When replacing fuses, be sure that the new fuse has the correct amperage rating. Do not exceed the rating or use one with a lower rating. (Scheme 7): Identifying Fuses Correct And Incorrect Condition (Scheme 8): Fuse Symbol Chart CLIPS The removal and installation methods of typical clips used for vehicle body parts are shown in the table below. HINT: If clips are damaged during a procedure, always replace the clips with new clips. (Scheme 9): Identifying Clip Removal/Installation Procedure CLAWS The removal and installation methods of typical claws used for vehicle body parts are shown in the table below. HINT: If claws of caps or covers are damaged during a procedure, always replace the caps or covers with new ones. (Scheme 10): Identifying Claws Removal/Installation Procedure REMOVAL AND INSTALLATION OF VACUUM HOSES To disconnect a vacuum hose, pull and twist from the end of the hose. Do not pull from the middle of the hose as this may cause damage. (Scheme 11): Identifying Correct And Incorrect Procedure For Vacuum Hose Disconnecting When disconnecting vacuum hoses, use tags to identify where they should be reconnected. After completing any hose related repairs, double-check that the vacuum hoses are properly connected. The label under the hood shows the proper layout. When using a vacuum gauge, never force the hose onto a connector that is too large. If a hose has been stretched, it may leak air. Use a step-down adapter if necessary. (Scheme 12): Identifying Correct Vacuum Hoses According To Tags TORQUE WHEN USING TORQUE WRENCH WITH EXTENSION TOOL (Scheme 13): Identifying Length Of Extension Tool And Torque Wrench Use the formula below to calculate special torque values for situations where SST or an extension tool is combined with a torque wrench. (Scheme 14): Identifying Length Of Extension Tool And Torque Wrench Formula: T' = L2 / (L1 + L2) * T SPECIAL TORQUE VALUES T' Reading of torque wrench {N*m (kgf*cm, ft.*lbf)} T Torque {N*m (kgf*cm, ft.*lbf)} L1 Length of SST or extension tool (cm (in.)} L2 Length of torque wrench {cm (in.)} NOTE: If an extension tool or SST is combined with a torque wrench and the wrench is used to tighten to a torque specification in this article, the actual torque will be excessive and parts will be damaged.
2. FOR VEHICLES WITH SUPPLEMENTAL RESTRAINT SYSTEM The LEXUS SC430 is equipped with a Supplemental Restraint System (SRS). The SRS of this vehicle consists of the following: Steering pad Driver side knee airbag assembly Front passenger side knee airbag assembly Front passenger airbag assembly Front seat side airbag assembly Center airbag sensor assembly Front airbag sensor Side airbag sensor Rear airbag sensor CAUTION: Failure to carry out service procedures in the correct sequence could cause SRS parts to unexpectedly deploy and possibly lead to serious injuries. Furthermore, if a mistake is made when servicing SRS parts, they may fail to operate when required. Before performing servicing (including installation/removal, inspection and replacement of parts), be sure to read the following precautions. Before starting work, wait at least 90 seconds after the ignition switch is turned OFF and after the cable of the negative (-) battery terminal is disconnected. (SRS parts are equipped with a backup power source. If work is started within 90 seconds of turning the ignition switch OFF and disconnecting the cable from the negative (-) battery terminal, SRS parts may deploy.) Do not expose SRS parts directly to hot air or flames. NOTE: Malfunction symptoms of SRS parts are difficult to confirm. DTCs are the most important source of information when troubleshooting. During troubleshooting, always confirm DTCs before disconnecting the cable from the negative (-) battery terminal. For minor collisions where SRS parts do not deploy, always inspect the SRS parts. Before performing repairs, remove airbag sensors as necessary if any kind of impact is likely to occur to an airbag sensor during repairs. Never use SRS parts from another vehicle. When replacing SRS parts, replace them with new ones. Never disassemble or attempt to repair SRS parts. If an SRS part has been dropped, or if there are any cracks, dents or other defects in the case, bracket or connector, replace the SRS part with a new one. Use an ohmmeter/voltmeter with high impedance (10 kohms/V minimum) for troubleshooting the electrical circuits. Information labels are attached to the periphery of SRS parts. Follow the cautions and instructions on the labels. After work on SRS parts is completed, perform the SRS warning light check. When the cable is disconnected from the negative (-) battery terminal, the memory settings of each system will be cleared. Because of this, be sure to write down the settings of each system before starting work. When work is finished, reset the settings of each system as before. Never use a backup power supply from outside the vehicle to avoid erasing the memory in a system. SPIRAL CABLE The steering wheel must be fitted correctly to the steering column with the spiral cable at the neutral position, as cable disconnection and other problems may occur. Refer to the information about correct installation of the steering wheel. AIRBAG ASSEMBLY Airbag assembly with pad: Always place a removed or new airbag assembly with the pad surface facing upward. Placing the airbag assembly with the airbag inflation direction facing downward could cause a serious accident if the airbag inflates. Also, do not place anything on top of the airbag assembly. Never measure the resistance of the airbag squib. This may cause the airbag to inflate, which could cause a serious injury. Grease or detergents of any kind should not be applied to the airbag assembly. Store the airbag assembly in an area where the ambient temperature is below 93°C (200°F), the humidity is not high and there is no electrical noise. When using electric welding anywhere on the vehicle, disconnect the airbag ECU connectors. These connectors contain shorting springs. This feature reduces the possibility of the airbag deploying due to currents entering the squib wiring. When disposing of the vehicle or the airbag assembly by itself, the airbag should be deployed using SST before disposal. Activate the airbag in a safe place away from electrical noise. SEAT OUTER BELT ASSEMBLY WITH PRETENSIONER Never measure the resistance of the seat outer belt. This may cause the pretensioner of the seat outer belt to activate, which could cause a serious injury. Never install the seat outer belt on another vehicle. Store the seat outer belt in an area where the ambient temperature is below 80°C (176°F), the humidity is not high and there is no electrical noise. When using electric welding anywhere on the vehicle, disconnect the airbag ECU connectors (2 pins). These connectors contain shorting springs. This feature reduces the possibility of the pretensioner deploying due to currents entering the squib wiring. When disposing of a vehicle or the seat outer belt by itself, the pretensioner should be activated before disposal. Activate the pretensioner in a safe place away from electrical noise. As the seat outer belt is hot after the pretensioner is activated, allow some time for it to cool down sufficiently before disposal. Never apply water to try to cool down the seat outer belt. Grease, detergents, oil or water should not be applied to the seat outer belt. AIRBAG SENSOR ASSEMBLY Never reuse an airbag sensor assembly that has been involved in a collision where the SRS has deployed. The connectors to the airbag sensor assembly should be connected or disconnected with the sensor placed on the floor. If the connectors are connected or disconnected while the airbag sensor assembly is not placed on the floor, the SRS may activate. Work must be started at least 90 seconds after the ignition switch is turned OFF and the cable is disconnected from the negative (-) battery terminal, 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 yellow. If the SRS wire harness becomes disconnected or the connector becomes broken, repair or replace it.
3. ELECTRONIC CONTROL REMOVAL AND INSTALLATION OF BATTERY TERMINAL NOTE: Certain systems need to be initialized after disconnecting and reconnecting the cable from the negative (-) battery terminal. (Scheme 15): Disconnecting Battery Negative Terminal Before performing electronic work, disconnect the cable from the negative (-) battery terminal to prevent component and wire damage caused by accidental short circuits. When disconnecting the cable, turn the ignition 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. 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. 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 rendered inoperative by static electricity. Do not pull the wires when disconnecting electronic connectors. Pull the connector. Be careful not to drop electronic components, such as sensors or relays. If they are dropped on a hard surface, they should be replaced. 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 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 PLACE FOR REMOVING AND INSTALLING FUEL SYSTEM PARTS Work in a location with good air ventilation that does not have welders, grinders, drills, electric motors, stoves, or any other ignition sources. Never work in a pit or near a pit as vaporized fuel will collect in those places. REMOVING AND INSTALLING FUEL SYSTEM PARTS Prepare a fire extinguisher before starting the operation. 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. Avoid using electric motors, working lights and other electric equipment that can cause sparks or high temperatures. Avoid using iron hammers as they may create sparks. (Scheme 16): Precaution - Handling Of Electronic Parts Dispose of fuel-contaminated cloth separately using a fire resistant container.
5. REMOVAL AND INSTALLATION OF ENGINE INTAKE PARTS If any metal particles enter inlet system parts, they may damage the engine. When removing and installing inlet system parts, cover the openings of the removed parts and engine openings. Use gummed tape or other suitable materials. When installing inlet system parts, check that no metal particles have entered the engine or the installed parts. (Scheme 17): Precaution - Removing And Installing Inlet System Parts
6. HANDLING OF HOSE CLAMPS Before removing the hose, check the clamp position so that it can be reinstalled in the same position. Replace any deformed or dented clamps with new ones. When reusing a hose, attach the clamp on the clamp track portion of the hose. 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. (Scheme 18): Identifying Spring Type Clamp
7. FOR VEHICLES EQUIPPED WITH MOBILE COMMUNICATION SYSTEMS Install the antenna as far away from the ECU and sensors of the vehicle electronic systems as possible. Install the 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. (Scheme 19): Identifying Antenna Feeder Keep the antenna and feeder separate from other wiring as much as possible. This will prevent signals of the communication equipment from affecting vehicle equipment and vice versa. Check that the antenna and feeder are correctly adjusted. Do not install a high-powered mobile communication system.
8. HEADLIGHT INSPECTION MAINTENANCE When the headlight dimmer switch assembly is set to HEAD, do not touch the discharge headlight's high-voltage socket area. NOTE: When performing inspection maintenance, the discharge headlight's precautions must be followed. When the headlights are illuminated, do not cover the headlights for 3 minutes or more. NOTE: 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. (Scheme 20): Precaution For Headlights
9. FOR VEHICLES EQUIPPED WITH TRAC (TRACTION CONTROL) SYSTEM AND VSC (VEHICLE STABILITY CONTROL) SYSTEM NOTICES FOR WHEN TESTING WITH 2-WHEEL DRUM TESTER 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 TRC 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, TRC 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. TRC and VSC operation must both be turned off before beginning testing. During VSC OFF mode, the combination meter's SLIP indicator light and VSC OFF indicator light illuminate. Fix the vehicle in place with chains for safety. NOTICES FOR VSC RELATED PROCEDURES For VSC related parts, adjustments are required after removal and installation. Therefore, perform removal and installation only when necessary. When performing VSC related procedures, be sure to strictly follow the preparation and completion procedures. When performing removal and installation or replacement of VSC related parts, first disconnect the cable from the negative (-) battery terminal. (Scheme 21): Identifying VSC OFF Indicator Light
10. 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. Use only unleaded gasoline. Avoid idling the engine for more than 20 minutes. Avoid performing unnecessary spark jump tests. 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.
11. INSPECTION AND ADJUSTMENT OF JOINT ANGLE DURING REMOVAL AND INSTALLATION OF PROPELLER SHAFT 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 «INSTALLATION»(/lexus/sc/ii-2005-2010/remont/driveshaft-universal-joints/#propeller-shaft) ). (Scheme 22): Locating Propeller Shaft Joint Angle

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1. NOTICE ABOUT VEHICLE CONDITION WHEN JACKING UP VEHICLE The vehicle must be unloaded before jacking up / lifting up the vehicle. Never jack up / lift up a heavily loaded vehicle. When removing heavy parts such as the engine and transmission, the center of gravity of the vehicle may shift. To stabilize the vehicle, place a balance weight in a location where it will not roll or shift, or use a mission jack to hold the jacking support.
2. NOTICE FOR USING 4 POST LIFT Follow the safety procedures outlined in the lift instruction manual. Use precautionary measures to prevent the free wheel beam from damaging tires or wheels. Use wheel chocks to secure the vehicle.
3. NOTICE FOR USING JACK AND SAFETY STAND Work on a level surface. Use wheel chocks at all times. Use safety stands with rubber attachments as shown in the illustration. Set the jack and safety stands to the specified locations of the vehicle accurately. When jacking up the vehicle, first release the parking brake and move the shift lever to N. When jacking up the entire vehicle: When jacking up the front wheels first, make sure wheel chocks are behind the rear wheels. When jacking up the rear wheels first, make sure wheel chocks are in front of the front wheels. (Scheme 23): Precaution - When Using Jack And Safety Stand When jacking up only the front or rear wheels of the vehicle: Before jacking up the front wheels, place wheel chocks on both sides of the rear wheels. Before jacking up the rear wheels, place wheel chocks on both sides of the front wheels. When lowering a vehicle that only has its front or rear wheels jacked up: Before lowering the front wheels, make sure wheel chocks are in front of the rear wheels. Before lowering the rear wheels, make sure wheel chocks are behind the front wheels. (Scheme 24): Identifying Vehicle Lifting Positions (Scheme 25): Vehicle Jack Position Chart (Scheme 26): Vehicle Support Position Chart It is extremely dangerous to perform any work on a vehicle raised on a jack alone, even for work that can be finished quickly. Safety stands must be used to support it.
4. NOTICE FOR USING SWING ARM TYPE LIFT Follow safety procedures outlined in its instruction manual. Use a swing arm equipped with a rubber attachment, as shown in the illustration. When using the lift, make sure that the vehicle is stabilized so that it will not tilt while work is being performed. Stabilize the vehicle by adjusting the lift arm's length and vehicle's position. When using the lift, its center should be as close to the vehicle's center of gravity as possible (length of "L" in the illustration should be as short as possible). (Scheme 27): Precaution - When Using Swing Arm Type Lift Set the vehicle on the lift as level as possible. Then match the groove of the cradle to the safety stand support locations. Be sure to lock the swing arms before lifting and during work (if equipped with arm locks). Lift the vehicle up off the ground. Stand at a safe distance and shake the vehicle to check its stability.
5. NOTICE FOR USING PLATE TYPE LIFT Follow safety procedures outlined in its instruction manual. Use plate lift attachments (rubber lifting blocks) on top of the plate surface. Refer to the illustration below to determine how to properly set the vehicle. (Scheme 28): Precaution - When Using Plate Type Lift HINT: VEHICLE POSITION CHART Right and left set position Place the vehicle over the center of the lift. Front and rear set position Place the attachments at the ends of the rubber plate surface, under the vehicle lift pad (A and C in the illustration). Raise the plate slightly and reposition the vehicle so the top of the attachment (B in the illustration) is aligned with the front side notch in the vehicle rocker flange. Use the lift to raise the vehicle up off the ground, and shake it to make sure that it is stable.

GENERAL INFORMATION

A large number of ECU controlled systems are used in the LEXUS SC430. In general, ECU controlled systems are considered to be very intricate, requiring a high level of technical knowledge to troubleshoot. However, most problem checking procedures only involve inspecting the ECU controlled system's circuits one by one. An adequate understanding of the system and a basic knowledge of electricity is enough to perform effective troubleshooting, accurate diagnoses and necessary repairs.

FOR USING INTELLIGENT TESTER

Connect the cable of the intelligent tester to the DLC3, turn the ignition switch ON and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.

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1. If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
2. If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual. (Scheme 29): Connecting Intelligent Tester To DLC3

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1. OPERATION FLOW HINT: Perform troubleshooting in accordance with the procedures below. The following is an outline of basic troubleshooting procedures. Confirm the troubleshooting procedures for the circuit you are working on before beginning troubleshooting. VEHICLE BROUGHT TO WORKSHOP CUSTOMER PROBLEM ANALYSIS Ask the customer about the conditions and environment when the problem occurred. INSPECT BATTERY VOLTAGE Standard voltage: 11 to 14 V If the voltage is below 11 V, recharge or replace the battery before proceeding. SYMPTOM CONFIRMATION AND DTC (AND FREEZE FRAME DATA) CHECK Visually check the wire harnesses, connectors and fuses for open and short circuits. Warm up the engine to the normal operating temperature. Confirm the problem symptoms and conditions, and check for DTCs. Result RESULT CHART Result Proceed to DTC is output A DTC is not output B B: Go to step 6 A: Go to step 6 DTC CHART Check the results obtained in the DTC check. Then find the output DTC in the DTC chart. Look at the "Trouble Area" column for a list of potentially malfunctioning circuits and / or parts. PROBLEM SYMPTOMS TABLE Check the results obtained in the symptom confirmation. Then find the problem symptoms in the problem symptoms table. Look at the "Suspected Area" column for a list of potentially malfunctioning circuits and / or parts. CIRCUIT INSPECTION OR PARTS INSPECTION Confirm the malfunctioning circuit or part. ADJUST, REPAIR OR REPLACE Adjust, repair or replace the malfunctioning circuit or parts. CONFIRMATION TEST After the adjustment, repairs or replacement, confirm that the malfunction no longer exists. If the malfunction does not reoccur, perform a confirmation test under the same conditions and in the same environment as when the malfunction occurred the first time. NEXT: END
2. CUSTOMER PROBLEM ANALYSIS HINT: In troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred. Gather as much information as possible for reference. Past problems that seem unrelated may also help in some cases. The following 5 items are important points in the problem analysis: PROBLEM ANALYSIS CHART What Vehicle model, system name When Date, time, occurrence frequency Where Road conditions Under what conditions? Running conditions, driving conditions, weather conditions How did it happen? Problem symptoms
3. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE HINT: The diagnostic system in the LEXUS SC430 has various functions. The first function is the Diagnostic Trouble Code (DTC) check. A DTC is a code stored in the ECU memory whenever a malfunction in the signal circuits to the ECU occurs. In a DTC check, a previous malfunction's DTC can be checked by a technician during troubleshooting. Another function is the Input Signal Check, which checks if the signals from various switches are sent to the ECU correctly. By using these functions, the problem areas can be narrowed down and troubleshooting is more effective. Diagnostic functions are incorporated in the following system in the LEXUS SC430. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHART System DTC Check (Normal Mode) DTC Check (Check Mode) Freeze Frame Data Sensor Check / Test Mode (Input Signal Check) Data List Active Test Customize Parameter SFI System (3UZ-FE) o o o - o o - Automatic Transmission System (A761E) o o o - o o - Tire Pressure Warning System o - - o o - - Vehicle Stability Control System o - o o o o - Power Tilt and Power Telescopic Steering Column System o - - - o o o Power Steering System o - - - - o - Air Conditioning System o - - - o o o Airbag System o - - - o - - Occupant Classification System o - - - o - - Seat Belt Warning System (w / Occupant Classification System) - - - - - o - Seat Belt Warning System (w / o Occupant Classification System) - - - - - o - Theft Deterrent System - - - - o o o Engine Immobiliser System o - - - o o - Cruise Control System o - - - o - - Lighting System o - - - o o - Wiper and Washer System - - - - o o - Power Door Lock Control System o - - - o o o Wireless Door Lock Control System o - - - o o o Luggage Compartment Door Opener System - - - - o o - Key Reminder Warning System - - - - o o o Meter / Gauge System - - - - o o o Audio and Visual System o - - - - - - Navigation System o - - - - - - Power Window Control System o - - - o o o Window Defogger System - - - - - o - Power Mirror Control System - - - - o o - Front Power Seat Control System - - - - o o - Fuel Lid Opener System - - - - o o - Retractable Hardtop System o - - - o - - Multiplex Communication System o - - - - - - CAN Communication System o - - - - - - In the DTC check, it is very important to determine whether the problem indicated by the DTC is either: 1) still occurring, or 2) occurred in the past but has since returned to normal. In addition, the DTC should be compared to the problem symptom to see if they are related. For this reason, DTCs should be checked before and after confirmation of symptoms (i.e., whether or not problem symptoms exist) to determine current system conditions, as shown in the flowchart below. Never skip the DTC check. Failing to check DTCs may, depending on the case, result in unnecessary troubleshooting for systems operating normally or lead to repairs not related to the problem. Follow the procedures listed in the flowchart in the correct order. The following flowchart shows how to proceed with troubleshooting using the DTC check. Directions from the flowchart will indicate how to proceed either to DTC troubleshooting or to the troubleshooting of each problem symptom. DTC CHECK MAKE A NOTE OF DTCS DISPLAYED AND THEN CLEAR MEMORY SYMPTOM CONFIRMATION Result RESULT CHART Result Proceed to No symptoms exist A Symptoms exist B B: Go to step 5 A: Go to step SIMULATION TEST USING SYMPTOM SIMULATION METHODS DTC CHECK Result RESULT CHART Result Proceed to DTC is not output A DTC is output B B: TROUBLESHOOTING OF PROBLEM INDICATED BY DTC A: Go to step SYMPTOM CONFIRMATION Result RESULT CHART Result Proceed to Symptoms exist A No symptoms exist B If a DTC was displayed in the initial DTC check, the problem may have occurred in a wire harness or connector in that circuit in the past. Check the wire harness and connectors. B: SYSTEM NORMAL A: TROUBLESHOOTING OF EACH PROBLEM SYMPTOM The problem is still occurring in a place other than the diagnostic circuit (the DTC displayed first is either for a past problem or a secondary problem).
4. SYMPTOM SIMULATION HINT: The most difficult case in troubleshooting is when no problem symptoms occur. In such a case, a thorough problem analysis must be carried out. A simulation of the same or similar conditions and environment in which the problem occurred in the customer's vehicle should be carried out. No matter how much skill or experience a technician has, troubleshooting without confirming the problem symptoms will lead to important repairs being overlooked and mistakes or delays. For example: With a problem that only occurs when the engine is cold or as a result of vibration caused by the road during driving, the problem can never be determined if the symptoms are being checked on a stationary vehicle or on a vehicle with a warmed-up engine. Vibration, heat or water penetration (moisture) is difficult to reproduce. The symptom simulation tests below are effective substitutes for the conditions and can be applied on a stationary vehicle. Important points in the symptom simulation test: In the symptom simulation test, the problem symptoms as well as the problem area or parts must be confirmed. First, narrow down the possible problem circuits according to the symptoms. Then, connect the tester and carry out the symptom simulation test, judging whether the circuit being tested is defective or normal. Also, confirm the problem symptoms at the same time. Refer to the problem symptoms table for each system to narrow down the possible causes. VIBRATION METHOD: When a malfunction seems to occur as a result of vibration. PART AND SENSOR Apply slight vibration with a finger to the part of the sensor suspected to be the cause of the problem, and check whether or not the malfunction occurs. NOTE: Applying strong vibration to relays may open them. CONNECTORS Slightly shake the connector vertically and horizontally. WIRE HARNESS Slightly shake the wire harness vertically and horizontally. HINT: The connector joint and fulcrum of the vibration are the major areas that should be checked thoroughly. (Scheme 30): Applying Slight Vibration With Finger HEAT METHOD: When a malfunction seems to occur when the area in question is heated. Heat the component that is the possible cause of the malfunction with a hair dryer or similar device. Check if the malfunction occurs. NOTE: Do not heat to more than 60°C (140°F). Exceeding this temperature may damage components. Do not apply heat directly to the parts in the ECU. WATER SPRINKLING METHOD: When a malfunction seems to occur on a rainy day or in high-humidity. Sprinkle water onto the vehicle and check if the malfunction occurs. (Scheme 31): Sprinkling Water Onto Vehicle NOTE: Never sprinkle water directly into the engine compartment. Indirectly change the temperature and humidity by spraying water onto the front of the radiator. Never apply water directly onto the electronic components. HINT: If the vehicle has or had a water leakage problem, the leakage may have damaged the ECU or connections. Look for evidence of corrosion or short circuits. Proceed with caution during water tests. HIGH ELECTRICAL LOAD METHOD: When a malfunction seems to occur when the electrical load is excessive. Turn on the heater blower, headlight, rear window defogger and all other electrical loads. Check if the malfunction reoccurs. (Scheme 32): Turning On Electrical Loads
5. DIAGNOSTIC TROUBLE CODE CHART Look for output Diagnostic Trouble Codes (DTCs) (from the DTC checks) in the appropriate section's Diagnostic Trouble Code Chart. Use the chart to determine the trouble area and the proper inspection procedure. A description of each of the chart's columns is below. DIAGNOSTIC TROUBLE CODE CHART Item Description DTC No. Indicates the diagnostic trouble code Detection Item Indicates the system or details of the problem Trouble Area Indicates the suspected areas of the problem See Page Indicates the page where the inspection procedures for each circuit are to be found, or gives instruction for checking and repairs
6. PROBLEM SYMPTOMS TABLE When a "Normal" code is output during a DTC check but the problem is still occurring, use the Problem Symptoms Table. The suspected areas (circuits or parts) for each problem symptom are in the table. The suspected areas are listed in order of probability. A description of each of the chart's columns is below. HINT: In some cases, the problem is not detected by the diagnostic system even though a problem symptom is present. It is possible that the problem is occurring outside the detection range of the diagnostic system, or that the problem is occurring in a completely different system. PROBLEM SYMPTOMS REFERENCE Item Description Symptom - Suspected Area Indicates the circuit or part which needs to be checked. See Page Indicates the page where the flowchart for each circuit is located.
7. CIRCUIT INSPECTION A description of the main areas of each circuit inspection is below. ITEM DESCRIPTION CHART Item Description Circuit Description The major role and operation of the circuit and its component parts are explained. DTC No., DTC Detection Condition, Trouble Area Indicates the diagnostic trouble codes, diagnostic trouble code detection conditions, and trouble areas of a problem. Wiring Diagram This shows a wiring diagram of the circuit. Use this diagram together with ELECTRICAL WIRING DIAGRAM to thoroughly understand the circuit. Wire colors are indicated by an alphabetical code: B = Black L = Blue R = Red BR = Brown LG = Light Green V = Violet G = Green O = Orange W = White GR = Gray P = Pink Y = Yellow SB = Sky Blue The first letter indicates the basic wire color and the second letter indicates the color of the stripe. Inspection Procedures Use the inspection procedures to determine if the circuit is normal or abnormal. If abnormal, use the inspection procedures to determine whether the problem is located in the sensors, actuators, wire harnesses or ECU. Inspection Procedure Connector Illustrations Connector being checked is connected: Connections of tester are indicated by (+) or (-) after the terminal name. Connector being checked is disconnected: For illustrations of inspections between a connector and body ground, information about the body ground is not shown in the illustration.

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

Scheme 38

Scheme 39

Scheme 40

Scheme 41

Scheme 42

Scheme 43

Scheme 44

Scheme 45

Scheme 46

1. BASIC INSPECTION WHEN MEASURING RESISTANCE OF ELECTRONIC PARTS Unless otherwise stated, all resistance measurements should be made at an ambient temperature of 20°C (68°F). Resistance measurements may be inaccurate if measured at high temperatures, i.e. immediately after the vehicle has been running. Measurements should be made after the engine has cooled down. HANDLING CONNECTORS When disconnecting a connector, first squeeze the mating halves tightly together to release the lock, and then press the lock claw and separate the connector. When disconnecting a connector, do not pull on the harnesses. Grasp the connector directly and separate it. Before connecting a connector, check that there are no deformed, damaged, loose or missing terminals. When connecting a connector, press firmly until it locks with a "click" sound. If checking a connector with a TOYOTA electrical tester, check the connector from the backside (harness side) using a mini test lead. (Scheme 33): Precaution For - Handling Connectors NOTE: As a waterproof connector cannot be checked from the backside, check it by connecting a sub-harness. Do not damage the terminals by moving the inserted tester needle. CHECKING CONNECTORS Checking when a connector is connected: Squeeze the connectors together to confirm that they are fully connected and locked. Checking when a connector is disconnected: Pull the wire harness lightly from the backside of the connector. Visually check for the following: 1) unlatched terminals, missing terminals, loose crimps and broken conductor wires; 2) corrosion, metallic matter, foreign matter and water; and 3) bent, rusted, overheated, contaminated and deformed terminals. (Scheme 34): Precaution For - Checking Connectors Checking the contact pressure of the terminal: Prepare a spare male terminal. Insert it into a female terminal, and check for ample tension when inserting and after full engagement. NOTE: When testing a gold-plated female terminal, always use a gold-plated male terminal. (Scheme 35): Checking Contact Pressure Of Terminal REPAIR METHOD OF CONNECTOR TERMINAL If there is any foreign matter on the terminal, clean the contact point using an air gun or cloth. Never rub the contact point using sandpaper as the plating may come off. If there is abnormal contact pressure, replace the female terminal. If the male terminal is gold-plated (gold color), use a gold-plated female terminal; if it is silver-plated (silver color), use a silver-plated female terminal. Damaged, deformed, or corroded terminals should be replaced. If the terminal does not lock into the housing, the housing may have to be replaced. (Scheme 36): Precaution For - Repair Method Of Connector Terminal HANDLING OF WIRE HARNESS If removing a wire harness, check the wiring and clamping before proceeding so that it can be restored in the same way. Never twist, pull or slacken the wire harness more than necessary. The wire harness should never come into contact with a high temperature part, or rotating, moving, vibrating or sharp-edged parts. Avoid contact with panel edges, screw tips and other sharp items. When installing parts, never pinch the wire harness. Never cut or break the cover of the wire harness. If it is cut or broken, repair the cover with vinyl tape or replace the wire harness. (Scheme 37): Precaution For - Handling Of Wire Harness
2. CHECK FOR OPEN CIRCUIT For an open circuit in the wire harness in (Scheme 38), check the resistance or voltage, as described below. (Scheme 38): Checking Resistance Or Voltage Between Connector Terminals Check the resistance. Disconnect connectors A and C, and measure the resistance between them. (Scheme 39): Measuring Resistance Between Connector Terminals Standard resistance (Scheme 39) TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition Connector A terminal 1 - Connector C terminal 1 10 kohms or higher Connector A terminal 2 - Connector C terminal 2 Below 1 ohms HINT: Measure the resistance while lightly shaking the wire harness vertically and horizontally. If the results match the examples above, an open circuit exists between terminal 1 of connector A and terminal 1 of connector C. Disconnect connector B and measure the resistance between the connectors. Standard resistance (Scheme 40) TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition Connector A terminal 1 - Connector B1 terminal 1 Below 1 ohms Connector B2 terminal 1 - Connector C terminal 1 10 kohms or higher (Scheme 40): Measuring Resistance Between Connector Terminals If the results match the examples above, an open circuit exists between terminal 1 of connector B2 and terminal 1 of connector C. Check the voltage. In a circuit in which voltage is applied to the ECU connector terminal, an open circuit can be checked by conducting a voltage check. With each connector still connected, measure the voltage between the body ground and these terminals (in this; order): 1) terminal 1 of connector A, 2) terminal 1 of connector B, and 3) terminal 1 of connector C. Standard voltage (Scheme 41) TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition Connector A terminal 1 - Body ground 5 V Connector B terminal 1 - Body ground 5 V Connector C terminal 1 - Body ground Below 1 V If the results match the examples above, an open circuit exists in the wire harness between terminal 1 of connector B and terminal 1 of connector C. (Scheme 41): Measuring Voltage Between Body Ground And Terminals
3. CHECK FOR SHORT CIRCUIT If the wire harness is ground shorted (Scheme 42), locate the section by conducting a resistance check with the body ground (below). (Scheme 42): Measuring Voltage Between Body Ground And Terminals Check the resistance with the body ground. Disconnect connectors A and C, and measure the resistance. Standard resistance (Scheme 43) TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition Connector A terminal 1 - Body ground Below 1 ohms Connector A terminal 2 - Body ground 10 kohms or higher (Scheme 43): Measuring Resistance Between Connector Terminals A And C HINT: Measure the resistance while lightly shaking the wire harness vertically and horizontally. If the results match the examples above, a short circuit exists between terminal 1 of connector A and terminal 1 of connector C. Disconnect connector B and measure the resistance. Standard resistance (Scheme 44) TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition Connector A terminal 1 - Body ground 10 kohms or higher Connector B2 terminal 1 - Body ground Below 1 ohms (Scheme 44): Measuring Resistance Between Connector Terminals A And B If the results match the examples above, a short circuit exists between terminal 1 of connector B2 and terminal 1 of connector C.
4. CHECK AND REPLACE ECU NOTE: The connector should not be disconnected from the ECU. Perform the inspection from the backside of the connector on the wire harness side. When no measuring condition is specified, perform the inspection with the engine stopped and the ignition switch ON. Check that the connectors are fully seated. Check for loose, corroded or broken wires. First, check the ECU ground circuit. If it is faulty, repair it. If it is normal, the ECU could be faulty. Temporarily replace the ECU with a normally functioning one and check if the problem symptoms occur. If the problem symptoms disappear, replace the original ECU. (Scheme 45): Measuring Resistance Between ECU Ground Terminal And Body Ground Measure the resistance between the ECU ground terminal and body ground. Standard resistance: Below 1 ohms Disconnect the ECU connector. Check the ground terminal on the ECU side and wire harness side for bending, corrosion or foreign matter. Lastly, check the contact pressure of the female terminals. (Scheme 46): Identifying ECU Connector Terminals

ABBREVIATIONS USED IN ARTICLE

ABBREVIATIONS MEANING CHART

See also:
• INSTALLATION