engine LEXUS GS400 2000 Service Repair Manual
[x] Cancel search | Manufacturer: LEXUS, Model Year: 2000, Model line: GS400, Model: LEXUS GS400 2000Pages: 1111, PDF Size: 22.85 MB
Page 622 of 1111
IN04S±10
IN±20± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
20 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the LEXUS GS400/GS300. In general, the ECU con-
trolled system is considered to be a very intricate system requiring a high level of technical knowledge and
expert skill to troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, trouble-
shooting of these systems is not complex. If you have adequate understanding of the system and a basic
knowledge of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the
problem. This manual is designed through emphasis of the above standpoint to help service technicians
perform accurate and effective troubleshooting, and is compiled for the following major ECU controlled sys-
tems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
1. Engine 2JZ ± GEDI±1
2. Engine 1UZ ± FEDI±156
3. Automatic TransmissionDI±316
4. ABS & Hydraulic Brake Booster Power Supply SystemDI±387
5. Vehicle Skid Control (VSC) & Brake Assist (BA) SystemDI±473
6. Power Tilt and Power Telescopic Steering ColumnDI±517
7. Supplemental Restraint SystemDI±550
8. Power Seat Control SystemDI±683
9. Cruise Control SystemDI±704
10.Engine Immobiliser SystemDI±726
11. Combination Meter SystemDI±744
12.Sliding Roof SystemDI±764
13.Body No. 1 Control SystemDI±776
14.Body No. 2 Control SystemDI±820
15.Driver Door Control SystemDI±856
16.Passenger Door Control SystemDI±889
17.Rear Left Door Control SystemDI±921
18.Rear Right Door Control SystemDI±938
19.Multiplex Communication SystemDI±955
20.LEXUS Navigation SystemDI±1022
21.Air Conditioning SystemDI±1059
FOR USING OBDII SCAN TOOL OR LEXUS HAND±HELD TESTER
Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.
If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Busline) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's
Manual.
Page 624 of 1111
Important Points in the Customer Problem Analysis
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
(Sample) Engine control system check sheet.
ENGINE CONTROL SYSTEM Check Sheet
Customer's Name
Driver's Name
Data Vehicle
Brought in
License No.
Model and Model
Year
Frame No.
Engine Model
Odometer Reading
km
miles
Problem Symptoms
Engine does
not Start
Difficult to
Start
Poor Idling
Poor
Drive ability
Engine Stall
Others
Engine does not crankNo initial combustionNo complete combustion
Engine cranks slowly
Other
Incorrect first idleIdling rpm is abnormalHigh ( rpm)Low ( rpm)
Rough idling
Other
HesitationBack fireMuffler explosion (after±fire)Surging
Knocking
Other
Soon after startingAfter accelerator pedal depressed
After accelerator pedal released
During A/C operation
Shifting from N to D
Other
Data Problem
ConstantSometimes ( times per day/month)
Inspector's
Name
CUSTOMER PROBLEM ANALYSIS CHECK
IN±22± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
22 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
1. CUSTOMER PROBLEM ANALYSIS
In troubleshooting, the problem symptoms must be confirmed accurately and all preconceptions must be
cleared away in order to give an accurate judgment. To ascertain just what the problem symptoms are, it is
extremely important to ask the customer about the problem and the conditions at the time it occurred.
Important Point in the Problem Analysis:
The following 5 items are important points in the problem analysis. Past problems which are thought to be
unrelated and the repair history, etc. may also help in some cases, so as much information as possible should
be gathered and its relationship with the problem symptoms should be correctly ascertained for reference
in troubleshooting. A customer problem analysis table is provided in Diagnostics section for each system
for your use.
Page 625 of 1111
DIAGNOSTIC TROUBLE CODE CHECK PROCEDURE
Diagnostic Trouble
Code Check (Make a
note of and then clear)Confirmation
of SymptomsDiagnostic Trouble
Code CheckProblem Condition
Diagnostic Trouble
Code DisplayProblem symptoms
existSame diagnostic
trouble code is
displayedProblem is still occurring in the diagnostic
circuit
Normal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit
(The diagnostic trouble code displayed
first is either for a past problem or it is a
secondary problem)
No problem
symptoms existThe problem occurred in the diagnostic
circuit in the past
Normal Code DisplayProblem symptoms
existNormal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit
No problem
symptoms existNormal code is
displayedThe problem occurred in a place other
than in the diagnostic circuit in the past
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±23
23 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the LEXUS GS400/GS300 fulfills various functions. The first function is the Diag-
nostic Trouble Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the
ECU memory at the time of occurrence, to be output by the technician during troubleshooting. Another func-
tion is the Input Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the LEXUS
GS400/GS300.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
Engine (2JZ±GE)
Engine (1UZ±FE)
Automatic Transmission
ABS & Hydraulic Brake Booster Power Supply System
Vehicle Skid Control (VSC) & Brake Assist (BA) System
Power Tilt and Power Telescopic Steering Column
Supplemental Restraint System
Cruise Control System
Engine Immobiliser System
Multiplex Communication System
LEXUS Navigation System
Air Conditioning System(with check Mode)
(with check Mode)
(with check Mode)
In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table below. If this is not done, it may, depending on the case, result in unnecessary troubleshooting
for normally operating systems, thus making it more difficult to locate the problem, or in repairs not pertinent
to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic trouble
code check.
Page 627 of 1111
V07268
VIBRATION METHOD: When vibration seems to be the major cause.
CONNECTORS
WIRE HARNESS
PARTS AND SENSOR1
Slightly shake the connector vertically and horizontally.
Slightly shake the wire harness vertically and horizontally.
The connector joint, fulcrum of the vibration, and body
through portion are the major areas to be checked thorough-
ly.
Apply slight vibration with a finger to the part of the sensor
considered to be the problem cause and check that the mal-
function occurs.Shake Slightly
Swing Slightly
Vibrate Slightly
HINT:
Applying strong vibration to relays may result in open relays.
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±25
25 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. SYMPTOM SIMULATION
The most difficult case in troubleshooting is when there are no problem symptoms occurring. In such cases,
a thorough customer problem analysis must be carried out, then simulate the same or similar conditions and
environment in which the problem occurred in the customer's vehicle. No matter how much experience a
technician has, or how skilled he may be, if he proceeds to troubleshoot without confirming the problem
symptoms he will tend to overlook something important in the repair operation and make a wrong guess
somewhere, which will only lead to a standstill. For example, for a problem which only occurs when the en-
gine is cold, or for a problem which occurs due to vibration caused by the road during driving, etc., the prob-
lem can never be determined so long as the symptoms are confirmed with the engine hot condition or the
vehicle at a standstill. Since vibration, heat or water penetration (moisture) is likely cause for problem which
is difficult to reproduce, the symptom simulation tests introduced here are effective measures in that the ex-
ternal causes are applied to the vehicle in a stopped condition.
Important Points in the Symptom Simulation Test:
In the symptom simulation test, the problem symptoms should of course be confirmed, but the problem area
or parts must also be found out. To do this, narrow down the possible problem circuits according to the symp-
toms before starting this test and connect a tester beforehand. After that, carry out the symptom simulation
test, judging whether the circuit being tested is defective or normal and also confirming the problem symp-
toms at the same time. Refer to the problem symptoms table for each system to narrow down the possible
causes of the symptom.
Page 628 of 1111
B02389
B02390
HEAT METHOD: When the problem seems to occur when the suspect area is heated. 2
NOTICE:3 WATER SPRINKLING METHOD:
(1)
(2)
4 OTHER: When a malfunction seems to occur when electrical load is excessive.When the malfunction seems to occur on a rainy day or in a
high±humidity condition. Heat the component that is the likely cause of the malfunction
with a hair dryer or similar object. Check to see if the malfunction
occurs.
Sprinkle water onto the vehicle and check to see if the malfunc-
tion occurs.
Turn on all electrical loads including the heater blower, head
lights, rear window defogger, etc. and check to see if the mal-
function occurs.ON HINT:
If a vehicle is subject to water leakage, the leaked water may
contaminate the ECU. When testing a vehicle with a water leak-
age problem, special caution must be taken.
Malfunc-
tion
Do not heat to more than 60 °C (140 °F). (Temperature
is limited not to damage the components.)
Do not apply heat directly to parts in the ECU. (1)
(2)
Never sprinkle water directly into the engine compart-
ment, but indirectly change the temperature and hu-
midity by applying water spray onto the radiator front
surface.
Never apply water directly onto the electronic compo-
nents. NOTICE: IN±26
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
26 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
Page 629 of 1111
DTC No.
Indicates the diagnostic trouble code.
Page or Instructions
Indicates the page where the inspection procedure
for each circuit is to be found, or gives instructions
for checking and repairs.
Detection Item
Indicates the system of the problem or
contents of the problem. Trouble Area
Indicates the suspect area of the
problem.
Mass Air Flow Circuit MalfunctionDetection Item
Open or short in mass air flow meter circuit
Mass air flow meter
ECM DTC No.
(See page)Trouble AreaMIL* MemoryP0100
(DI±24)
P0101
(DI±28)
P0115
(DI±33) Open or short in intake air temp. sensor
circuit
Intake air temp. sensor
ECM Intake Air Temp. Circuit
Malfunction P0110
(DI±29)
Open or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
Throttle/ Pedal Position Sensor/Switch
ºAº Circuit MalfunctionEngine Coolant Temp.
Circuit Malfunction
Open or short in throttle position sensor circuit
Throttle position sensor
ECM
DTC CHART (SAE Controlled)
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument or other
factors.
If a malfunction code is displayed during the DTC check mode, check the circuit for that code listed in the table
below. For details of each code, turn to the page referred to under the ºSee pageº for the respective ºDTC No.º
in the DTC chart.
Mass Air Flow Circuit
Range/ Performance Problem Mass air flow meter
Throttle position sensor Throttle/ Pedal Position Sensor/ Switch
ºAº Circuit Range / Performance Prob-
lem P0116
(DI±37)Engine Coolant Temp.
Circuit Range/ Performance Problem Engine coolant temp. sensor
Cooling system
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±27
27 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. DIAGNOSTIC TROUBLE CODE CHART
The inspection procedure is shown in the table below. This table permits efficient and accurate troubleshoot-
ing using the diagnostic trouble codes displayed in the diagnostic trouble code check. Proceed with trouble-
shooting in accordance with the inspection procedure given in the diagnostic chart corresponding to the
diagnostic trouble codes displayed. The engine diagnostic trouble code chart is shown below as an example.
Page 630 of 1111
IN±28± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
28 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. PROBLEM SYMPTOMS TABLE
The suspected circuits or parts for each problem symptom are shown in the table below. Use this table to
troubleshoot the problem when a ºNormalº code is displayed in the diagnostic trouble code check but the
problem is still occurring. Numbers in the table indicate the inspection order in which the circuits or parts
should be checked.
HINT:
When the problem is not detected by the diagnostic system even though the problem symptom is present,
it is considered that the problem is occurring outside the detection range of the diagnostic system, or that
the problem is occurring in a system other than the diagnostic system.
Symptom
Suspect AreaSee page
Engine does not crank (Does not start)
No initial combustion (Does not start)
No complete combustion (Does not start)1. Starter and starter relay
1. ECM power source circuit
2. Fuel pump control circuit
3. Engine control module (ECM)
1. Starter signal circuit
2. Fuel pump control circuit1. Fuel pump control circuitDI±147
DI±151
IN±29
PROBLEM SYMPTOMS TABLE
1. Compression
2. Fuel pump control circuit 1. A/C signal circuit
2. Fuel pump control circuit 1. A/C signal circuit (Compressor circuit)
2. ECM power source circuit 1. Starter signal circuit
2. Fuel pump control circuit1. Starter signal circuit
2. Fuel pump control circuit
3. Compression
idling) High engine idle speed (Poor idling) Hot engine Cold engine (Difficult to start)Engine cranks normally (Difficult to start)
AC±88 DI±144
DI±151
EM±3 DI±151
Problem Symptom Page
Indicates the page where the flow chart for each circuit
is located.
Circuit Inspection, Inspection Order
Indicates the circuit which needs to be checked for each problem
symptom. Check in the order indicated by the numbers.
Circuit or Part Name
Indicates the circuit or part which needs to be checked.
ST±2
ST±17
DI±144
DI±151
DI±144
DI±151
Page 631 of 1111
V08423 Knock Sensor 1
GRECM
KNK
E1 12
E6
WIRING DIAGRAM
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.
DTC P0325Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric element which
generates a voltage when it becomes deformed, which occurs when the cylinder block vibrates due to knocking. If engine
knocking occurs, ignition timing is retarded to suppress it.
DTC No. DTC Detecting Condition Trouble Area
P0325No knock sensor 1 signal to ECM with engine speed,
1,200 rpm or more. Open or short in knock sensor1 circuit
Knock sensor 1 (looseness)
ECM
If the ECM detects the above diagnosis conditions, it operates the fall safe function in which the corrective retard angle
value is set to the maximum value.
Diagnostic Trouble Code No. and Detection Item
Circuit Description
The major role and operation, etc. of the circuit
and its component parts are explained.
Indicates the diagnostic trouble code, diagnostic
trouble code set parameter and suspect area of
the problem.
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±29
29 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. CIRCUIT INSPECTION
How to read and use each page is shown below.
Page 633 of 1111
IN04P±03
B01547
B A
B01548
1UZ ± FE engine: 2JZ ±GE engine:
B02384
B01554
± INTRODUCTIONIDENTIFICATION INFORMATION
IN±3
3 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
IDENTIFICATION INFORMATION
VEHICLE IDENTIFICATION AND
ENGINE SERIAL NUMBER
1. VEHICLE IDENTIFICATION NUMBER
The vehicle identification number is stamped on the vehicle
identification number plate and the certification label, as shown
in the illustration.
A: Vehicle Identification Number Plate
B: Certification Label
2. ENGINE SERIAL NUMBER
The engine serial number is stamped on the engine block, as
shown in the illustration.
Page 640 of 1111
± INTRODUCTIONTERMS
IN±37
37 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) CW
Curb Weight
DCDirect Current
DEFDefogger
DFLDeflector
DIFF.Differential
DIFF. LOCKDifferential Lock
D/INJDirect Injection
DLIDistributorless Ignition
DOHCDouble Over Head Cam
DPDash Pot
DSDead Soak
DSPDigital Signal Processor
EBDElectronic Brake Force Distribution
ECAMEngine Control And Measurement System
ECDElectronic Controlled Diesel
ECDYEddy Current Dynamometer
ECUElectronic Control Unit
EDElectro±Deposited Coating
EDICElectric Diesel Injection Control
EDUElectronic Driving Unit
EFIElectronic Fuel Injection
E/GEngine
EGR±VMEgr±Vacuum Modulator
ELREmergency Locking Retractor
ENGEngine
ESAElectronic Spark Advance
ETCSElectronic Throttle Control System
EVPEvaporator
E±VRVElectric Vacuum Regulating Valve
EXHExhaust
FEFuel Economy
FFFront±Engine Front±Wheel±Drive
F/GFuel Gage
FIPGFormed In Place Gasket
FLFusible Link
F/PFuel Pump
FPUFuel Pressure Up
FrFront
FRFront±Engine Rear±Wheel±Drive
F/WFlywheel
FW/DFlywheel Damper
FWDFront±Wheel±Drive
GASGasoline
GNDGround
HACHigh Altitude Compensator
H/BHatchback