Lexus GS300/400 (2000 year). Service manual - part 156

F02415

A

B

C

No. 2 Joint
A – B = – 1

°

01’ 

± 

37’

No. 3 Joint
B – C = + 1

°

14’ 

± 

42’

B07465

New

Previous

–

INTRODUCTION

FOR ALL OF VEHICLES

IN–19

19

6.

INSPECTION AND ADJUSTMENT OF JOINT ANGLE
DURING REMOVAL AND INSTALLATION OF PROPEL-
LER SHAFT

When performing operations which involve the removal and
installation of the propeller shaft, always check the joint angle.
Make adjustments if necessary (See page 

PR–12

).

7.

FOR VEHICLES EQUIPPED WITH BRAKE PIPE FIT-
TING OF NEW STANDARD

A flare shape of a new standard is used for the brake pipe fitting
from this changed models.
NOTICE:

When ordering or replacing the parts, please be sure
to check and use the fitting of the same flare type.

Do not over–tighten them more than the standard
torque.
Torque: 15 N·m (155 kgf·cm, 11 ft·lbf)

IN04S–10

IN–20

–

INTRODUCTION

HOW TO TROUBLESHOOT ECU CONTROLLED 
SYSTEMS

20

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.

System

Page

1. Engine

2JZ – GE

DI–1

2. Engine

1UZ – FE

DI–156

3. Automatic Transmission

DI–316

4. ABS & Hydraulic Brake Booster Power Supply System

DI–387

5. Vehicle Skid Control (VSC) & Brake Assist (BA) System

DI–473

6. Power Tilt and Power Telescopic Steering Column

DI–517

7. Supplemental Restraint System

DI–550

8. Power Seat Control System

DI–683

9. Cruise Control System

DI–704

10.Engine Immobiliser System

DI–726

11.Combination Meter System

DI–744

12.Sliding Roof System

DI–764

13.Body No. 1 Control System

DI–776

14.Body No. 2 Control System

DI–820

15.Driver Door Control System

DI–856

16.Passenger Door Control System

DI–889

17.Rear Left Door Control System

DI–921

18.Rear Right Door Control System

DI–938

19.Multiplex Communication System

DI–955

20.LEXUS Navigation System

DI–1022

21.Air Conditioning System

DI–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 (Bus

line) 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.

IN04T–08

Vehicle Brought to Workshop

Customer Problem
Analysis

Symptom Confirmation
and Diagnostic Trouble
Code Check

Symptom Simulation

Diagnostic Trouble 
Code Chart

Problem Symptoms Table

Circuit Inspection or Parts
Inspection

Repair

Confirmation Test

End

1

2

4

3

5

6

7

8

Ask the customer about the conditions and the
environment when the problem occurred.

1

Confirm the symptoms and the problem conditions,
and check the diagnostic trouble codes.
(When the problem symptoms do not appear 
during confirmation, use the symptom simulation
method described later on.)

2, 3

Check the results obtained in Step 2, then confirm 
the inspection procedure for the system or the part
which should be checked using the diagnostic
trouble code chart or the problem symptoms table.

4, 5, 6

Check and repair the affected system or part in 
accordance with the instructions in Step 6.

7

After completing repairs, confirm that the problem 
has been eliminated.
(If the problem is not reproduced, perform the
confirmation test under the same conditions and
in the same environment as when it occurred for
the first time.)

8

–

INTRODUCTION

HOW TO TROUBLESHOOT ECU CONTROLLED 
SYSTEMS

IN–21

21

HOW TO PROCEED WITH TROUBLESHOOTING

Carry out troubleshooting in accordance with the procedure on the following page. Here, only the basic pro-
cedure is shown. Details are provided in Diagnostics section, showing the most effective methods for each
circuit. Confirm the troubleshooting procedures first for the relevant circuit before beginning troubleshooting
of that circuit.

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 crank

No initial combustion

No complete combustion

Engine cranks slowly

Other

Incorrect first idle

Idling rpm is abnormal

High (                    rpm)

Low (                    rpm)

Rough idling

Other

Hesitation

Back fire

Muffler explosion (after–fire)

Surging

Knocking

Other

Soon after starting

After accelerator pedal depressed

After accelerator pedal released

During A/C operation

Shifting from N to D

Other

Data Problem

Constant

Sometimes (          times per          day/month)

Inspector’s
Name

CUSTOMER PROBLEM ANALYSIS CHECK

IN–22

–

INTRODUCTION

HOW TO TROUBLESHOOT ECU CONTROLLED 
SYSTEMS

22

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.