Introduction: Overview Lexus LS IV

Scheme 1

1. GENERAL DESCRIPTION This information 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 information. However, these procedures must be performed. Use a jack or lift to perform operations Clean all removed parts Perform a visual check
2. 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 procedure properly. A list of SST and SSM is in the «PREPARATION»(/lexus/ls/iv-2006-2012/remont/accessories-control-systems/#preparation) article .
3. 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. 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, the information is 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. ILLUSTRATIONS REFERENCE Illustration What to do and where to do it Task heading What work will be performed Explanation text How to perform the task Also has 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.
4. SERVICE SPECIFICATIONS SPECIFICATIONS are presented in boldface text throughout the information. The specifications are also found in the «SERVICE SPECIFICATIONS» article for reference.
5. 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.
6. INTERNATIONAL SYSTEM OF UNITS The units used in this information comply with the International System of Units (SI) standard. Units from the metric system and the English systems are also provided. Below is an example. Torque: 30 N*m (310 kgf*cm, 22 ft.*lbf)

Scheme 2

Scheme 3

Scheme 4

Scheme 5

1. VEHICLE IDENTIFICATION NUMBER The vehicle identification number is stamped on the vehicle identification number plate and certification label, as shown in the illustrations. 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 Transmission Serial Number

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Scheme 29

Scheme 30

Scheme 31

Scheme 32

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

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

1. BASIC REPAIR HINT HINTS ON OPERATIONS 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. 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. If the wire of a fuse is broken, confirm that there are no shorts in its circuit. When a fuse is replaced, a fuse with the same amperage rating must be used. FUSE REFERENCE CHART Illustration Symbol Part Name Abbreviation FUSE FUSE MEDIUM CURRENT FUSE M-FUSE HIGH CURRENT FUSE H-FUSE FUSIBLE LINK FL CIRCUIT BREAKER CB 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. REMOVAL AND INSTALLATION METHODS OF TYPICAL CLIPS Shape (Example) Illustration Procedures Remove clips with a clip remover or pliers. Remove clips with a clip remover or screwdriver. Remove clips with a wide scraper to prevent panel damage. Remove clips by pushing the center pin through and prying out the shell. Remove clips by unscrewing the center pin and prying out the shell. Remove clips by prying out the pin and then prying out the shell. 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. REMOVAL AND INSTALLATION METHODS OF TYPICAL CLAWS Shape (Example) Illustration Procedures Using a screwdriver, detach the claws and remove the caps or covers. Using a screwdriver, detach the claws and remove the caps or covers. Using a screwdriver, detach the claws and remove the caps or covers. HINGE, GUIDE, CLAMP, PIN ETC. The removal and installation methods of typical hinges, guides, clamps and pins used for vehicle body parts are shown in the table below. HINT: If clamps are damaged during a procedure, always replace the cap or cover that has damaged clamps with a new one. REMOVAL AND INSTALLATION METHODS OF TYPICAL HINGES, GUIDES, CLAMPS AND PINS Shape (Example) Illustration Procedures Disengage the pins by pulling. Disengage the pins by pulling. Remove the clamps with pliers. Disengage the pins by pulling. 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. 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. TORQUE WHEN USING TORQUE WRENCH WITH EXTENSION TOOL Use the formula below to calculate special torque values for situations where SST or an extension tool is combined with a torque wrench. Formula: T' = L2/(L1 + L2) * T FORMULA LEGENDS 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 LS460L/LS460 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 Curtain shield airbag assembly Front seat side airbag assembly Rear seat side airbag assembly Center airbag sensor assembly Seat cushion airbag assembly Front airbag sensor Side airbag sensor Rear airbag sensor Seat position airbag sensor Occupant classification ECU Front seat outer belt assembly with pretensioner Rear seat outer belt assembly with pretensioner 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 engine 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 engine 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. An airbag or pretensioner may be activated by static electricity. To prevent this, be sure to touch a metal surface with bare hands to discharge static electricity before performing this procedure. 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 center airbag sensor 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 center airbag sensor 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 engine 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: For the LEXUS LS460L/LS460, the cowl top ventilator louver is covering the battery. When disconnecting and reconnecting the cable from the negative (-) battery terminal or replacing the battery, the cowl top ventilator louver must be removed. After handling the battery cable or replacing the battery, be sure to install the cowl top ventilator louver properly. If it is not installed properly, water (rain, car wash, etc.) may enter the engine room and cause malfunctions. 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 engine switch off and headlight dimmer switch OFF and loosen the cable nut completely. Perform these operations without twisting or prying the cable. Then disconnect the cable. Clock settings, radio settings, audio system memory, DTCs and other data are cleared when the cable is disconnected from the negative (-) battery terminal. Write down any necessary data before disconnecting the cable. Certain systems need to be initialized after disconnecting and reconnecting the cable from the negative (-) battery terminal. 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. Dispose of fuel-contaminated cloths 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.
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.
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 article of the applicable components. Keep the antenna and feeder separate from other wiring as much as possible. This will prevent signals from 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.
9. FOR VEHICLES EQUIPPED WITH TRAC (TRACTION CONTROL) SYSTEM AND VSC (VEHICLE STABILITY CONTROL) SYSTEM Notices for when using a chassis dynamometer. Position the front wheels on free rollers or support the vehicle with safety stands and make sure the front wheels can rotate freely. When testing with a speedometer tester, a combination tester for the speedometer and brake, a chassis dynamometer or similar, be sure to enter "Test mode" and prohibit the TRC and VSC controls. After completing the inspection, be sure to exit "Test mode". NOTE: Never drive the vehicle while in "Test mode". 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, VSC OFF is displayed in the multi-information display, and the combination meter's slip indicator light illuminates. 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.
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. When performing 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. WHEN TOWING FULL-TIME AWD VEHICLES Use one of the methods shown below to tow the vehicle. If the vehicle has trouble in the chassis and drive train, use method 1 (flat bed truck). TOWING METHOD OF VEHICLES Towing Method Parking Brake Condition Transmission Shift Lever Position 1. Flat Bed Truck Applied Any Position 2. Wheel Lift Type Truck from Front Applied NOTE: Do not use any towing method other than those shown above. For example, the towing methods shown below are dangerous or may damage the vehicle, so do not use them. PRECAUTION OF TOWING METHODS Never tow the vehicle using a method where the lifted-up wheels cannot rotate. If this towing method is used, either from the front or rear: There is a danger of the drive train heating up and causing a breakdown, or of the wheels flying off the dolly. In addition, if the vehicle is equipped with a Vehicle Stability Control (VSC) and Traction Control (TRAC) system, the system will apply the brakes of the rotating wheels unless the engine is shut off. Do not use the sling type method, either from the front or rear, as this method causes damage to the body.
12. 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.

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

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 transmission jack to hold the jacking support.
2. NOTICE FOR USING 4 POST LIFT Follow the safety procedures outlined in the lift's instruction article. 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. 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. 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 the vehicle.
4. NOTICE FOR USING SWING ARM TYPE LIFT Follow the safety procedures outlined in the lift's instruction article. 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). 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 the safety procedures outlined in the lift's 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. HINT: POSITION FOR SETTING VEHICLE Left and right set position Place the vehicle over the center of the lift. Front and rear set position When using attachments: 1) place the vehicle front attachments with the 70 x 200 mm (2.76 x 7.87 in.) side facing the front/rear of the vehicle; and 2) place the vehicle rear attachments with the 70 x 100 mm (2.76 x 3.94 in.) side facing the front/rear of the vehicle. Align the cushion gum ends of the plate with the attachment lower ends (A, C). Align the attachment upper end (B) with the rocker flange rear side notch. 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 LS460L/LS460. 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.

Scheme 58

1. TROUBLESHOOTING PROCEDURES The troubleshooting procedures consist of diagnosis procedures for when a DTC is stored and diagnosis procedures for when no DTC is stored. The basic idea is explained in the following table. TROUBLESHOOTING PROCEDURE Procedure Type Details Troubleshooting Method DTC Based Diagnosis The diagnosis procedure is based on the DTC that is stored. The malfunctioning part is identified based on the DTC detection conditions using a process of elimination. The possible trouble areas are eliminated one-by-one by use of the intelligent tester and inspection of related parts. Symptom Based Diagnosis (No DTCs stored) The diagnosis procedure is based on problem symptoms. The malfunctioning part is identified based on the problem symptoms using a process of elimination. The possible trouble areas are eliminated one-by-one by use of the intelligent tester and inspection of related parts. Vehicle systems are complex and use many ECUs that are difficult to inspect independently. Therefore, a process of elimination is used, where components that can be inspected individually are inspected, and if no problems are found in these components, the related ECU is identified as the problem and replaced. It is extremely important to ask the customer about the environment and the conditions present when the problem occurred (Customer Problem Analysis). This makes it possible to simulate the conditions and confirm the symptom. If the symptom cannot be confirmed or the DTC does not recur, the malfunctioning part may not be identified using the troubleshooting procedure, and the ECU for the related system may be replaced even though it is not defective. If this happens, the original problem will not be solved. In order to prevent endless expansion of troubleshooting procedures, the troubleshooting procedures are written with the assumption that multiple malfunctions do not occur simultaneously for a single problem symptom. To identify the malfunctioning part, troubleshooting procedures narrow down the target by separating components, ECUs and wire harnesses during the inspection. If the wire harness is identified as the cause of the problem, it is necessary to inspect not only the connections to components and ECUs but also all of the wire harness connectors between the component and the ECU. DIAGNOSTIC TESTER
2. DESCRIPTION System data and the Diagnostic Trouble Codes (DTCs) can be read from the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream* to check for a malfunction and perform repairs. HINT: *: Techstream is the name for the diagnostic tester in North America.
3. DATA LINK CONNECTOR 3 (DLC3) The vehicle's ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format. DLC3 CONNECTOR TERMINALS VOLTAGE AND RESISTANCE SPECIFIED CONDITION Terminal No. (Symbols) Terminal Description Condition Specified Condition 7 (SIL) - 5 (SG) Bus "+" line During transmission Pulse generation 4 (CG) - Body ground Chassis ground Always Below 1 ohms 5 (SG) - Body ground Signal ground Always Below 1 ohms 16 (BAT) - Body ground Battery positive Always 11 to 14 V 6 (CANH) - 14 (CANL) CAN bus line Engine switch off (1) 54 to 69 ohms 6 (CANH) - 4 (CG) HIGH-level CAN bus line Engine switch off (1) 200 ohms or higher 14 (CANL) - 4 (CG) LOW-level CAN bus line Engine switch off (1) 200 ohms or higher 6 (CANH) - 16 (BAT) HIGH-level CAN bus line Engine switch off (1) 6 kohms or higher 14 (CANL) - 16 (BAT) LOW-level CAN bus line Engine switch off (1) 6 kohms or higher (1) Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, any other switches, or the doors. If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector. Connect the cable of the Techstream to the DLC3, turn the engine switch on (IG) 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. HINT: If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle. 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 59

Scheme 60

Scheme 61

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 (INCLUDING 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 DTC OUTPUT RESULT Result Proceed to DTC is output A DTC is not output B B: Go to step 6 A: Go to Next Step 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. NEXT: Go to step 7 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 questions are important points in the problem analysis: CUSTOMER PROBLEM ANALYSIS QUESTIONS 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 LS460L/LS460 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 systems in the LEXUS LS460L/LS460. SYSTEM REFERENCE 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 (1UR-FSE) o o o - o o - Smart Access System with Push-button Start (for Starting) o - - - o o - Automatic Transmission System (AA80E, AA80F) o o o - o o - Air Suspension System o - - o o o - Tire Pressure Warning System o - - o o o - Electronically Controlled Brake System o - o o o o - Electric Parking Brake System o - o - o o - Power Tilt and Power Telescopic Steering Column System o - o - o o o Steering Lock System o - - - o - - Heated Steering Wheel System - - - - - o - Variable Gear Ratio Steering System o - o o o o - Power Steering System o - o - o - - Air Conditioning System o - - - o o o Pre-collision System o - - - o o - Airbag System o o - - o - - Occupant Classification System o - - - o - - Power Shoulder Belt Anchorage System - - - - o o - RSE - - - - - - - Seat Belt Warning System - - - - - o - Theft Deterrent System o - - - o o o Engine Immobilizer System o - - - o o - Cruise Control System o - - - o o - Dynamic Radar Cruise Control System o - - - o o - Lighting System o - - - o o o Wiper and Washer System o - - - o o - Power Door Lock Control System o - - - o o o Wireless Door Lock Control System o - - - o o o Smart Access System with Push-button Start (for Door Lock) - - - - o o o Meter/Gauge System o - - - o o o Audio and Visual System (w/ Multi-display) o - - - - - - Audio and Visual System (w/o Multi-display) o - - - - - - Navigation System (for DVD) o - - - - - - Navigation System (for HDD) o - - - - - - Intuitive Parking Assist System o - - - o o o Advanced Parking Guidance System o - - - o - - Electric Power Control System o - - - o o - Horn System o - - - o o - LEXUS Link System o - - - o - - Power Window Control System o - - - o o o Windshield Deicer System - - - - - o - Window Defogger System - - - - - o - Power Mirror Control System - - - - o o - Front Power Seat Control System o - - - o o - Rear Power Seat Control System o - - - o o - Seat Heater System o - - - o o - Climate Control Seat System o - - - o o - Door Closer System - - - - o - - Luggage Compartment Door Opener System - - - - o o - Luggage Compartment Door Closer System o - - - o - - Fuel Lid Opener System - - - - o o - Power Trunk Lid System o - - - o o o Rear Sunshade System o - - - o o o Rear Door Sunshade System o - - - o o - Sliding Roof System o - - - o o o LIN Communication System o - - - 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 Next Step SIMULATION TEST USING SYMPTOM SIMULATION METHODS DTC CHECK Result DTC OUTPUT RESULT Result Proceed to DTC is not output A DTC is output B B: TROUBLESHOOTING OF PROBLEM INDICATED BY DTC A: Go to Next 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. To reproduce DTCs, it is necessary to satisfy the respective DTC detection conditions. 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. 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. 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, headlights, rear window defogger and all other electrical loads. Check if the malfunction reoccurs.
5. DIAGNOSTIC TROUBLE CODE CHART Look for output Diagnostic Trouble Codes (DTCs) (from the DTC checks) in the appropriate article'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. ITEM DESCRIPTION CHART Item Description DTC Code 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 Indicates the article where the inspection procedures for each circuit can be found, or where there are instructions for checks 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 CHART Item Description Symptom - Suspected Area Indicates the circuit or part which needs to be checked. See Indicates the article where the flowchart for each circuit is located.
7. CIRCUIT INSPECTION A description of the main areas of each circuit inspection is below. DESCRIPTION CHART Item Description Circuit Description The major role and operation of the circuit and its component parts are explained. DTC Code, 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 an ELECTRICAL WIRING DIAGRAM to thoroughly understand the circuit. 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 62

Scheme 63

Scheme 64

Scheme 65

Scheme 66

Scheme 67

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

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. 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: Check by pulling the wire harness lightly from the backside of the connector. Look for unlatched terminals, missing terminals, loose crimps or broken conductor wires. Check visually for corrosion, metallic or foreign matter and water, and bent, rusted, overheated, contaminated, or deformed terminals. 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. 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. 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, replace it or repair it with vinyl tape.
2. CHECK FOR OPEN CIRCUIT For an open circuit in the wire harness in see scheme 119, check the resistance or voltage, as described below. Check the resistance. Disconnect connectors A and C and measure the resistance between them. Standard resistance see scheme 120 RESISTANCE 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 see scheme 121 RESISTANCE 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 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 see scheme 122 VOLTAGE 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.
3. CHECK FOR SHORT CIRCUIT If the wire harness is ground shorted see scheme 123, locate the article by conducting a resistance check with the body ground (below). Check the resistance with the body ground. Disconnect connectors A and C and measure the resistance. Standard resistance see scheme 124 RESISTANCE 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 HINT: Measure the resistance while lightly shaking the wire harness vertically and horizontally. If your 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 see scheme 125 RESISTANCE 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 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 engine switch ON (IG). 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 symptoms occur. If the trouble symptoms disappear, replace the original ECU. 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.

ABBREVIATIONS USED

ABBREVIATIONS LIST

See also:
• PREPARATION