automatic transmission LEXUS GS400 2000 Service Owner's Guide

Q03099
17 mm
Head
14 mm Head17 mm Head
Q06924
± AUTOMATIC TRANSMISSIONAUTOMATIC TRANSMISSION UNIT (1UZ±FE)
AT±37
1985 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
15. REMOVE TRANSMISSION
Remove the 10 bolts and transmission.
Torque:
17 mm head: 72 N´m (730 kgf´cm, 53 ft´lbf)
14 mm head: 37 N´m (380 kgf´cm, 27 ft´lbf)
HINT:
At the time of installation, please refer to the following item.
Lift the front side of the engine.

AT06C±01
D01007
AT±38
± AUTOMATIC TRANSMISSIONAUTOMATIC TRANSMISSION UNIT (1UZ±FE)
1986 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSTALLATION
1. CHECK TORQUE CONVERTER CLUTCH INSTALLA-
TION
Using calipers and a straight edge, measure the distance from
the installed surface of the transmission housing to the installed
surface of the torque converter clutch.
Correct distance: More than 17.1 mm (0.673 in.)
If the distance is less than the standard, check for an improper
installation.
2. INSTALL TRANSMISSION
Installation is in the reverse order of removal.
(See page AT±34)
HINT:
After installation, check and inspect items as follows.

Adjust the shift lever position. (See page DI±318)

Fill ATF and check fluid level. (See page DI±318)

Do the road test. (See page DI±318)

AT5436
SST
AT06D±01
AT5437
Lock
Free
Q03546
AT4184
± AUTOMATIC TRANSMISSIONTORQUE CONVERTER CLUTCH AND DRIVE PLATE
AT±39
1987 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
TORQUE CONVERTER CLUTCH
AND DRIVE PLATE
INSPECTION
1. INSPECT ONE±WAY CLUTCH
(a) Install SST so that it fits in the notch of the converter hub
and outer race of the one±way clutch.
SST 09350±30020 (09351±32020)
(b) Press on the serrations of stater with a finger and rotate
it.
Check if it rotates smoothly when turned clockwise and
locks up when turned counterclockwise.
2. MEASURE DRIVE PLATE RUNOUT AND INSPECT
RING GEAR
Set up a dial indicator and measure the drive plate runout.
Maximum runout: 0.20 mm (0.0079 in.)
If runout exceeds 0.20 mm (0.0079 in.) or if the ring gear is dam-
aged, replace the drive plate. If installing a new drive plate, note
the orientation of spacers and tighten the bolts.
Torque: 83 N´m (850 kgf´cm, 61 ft´lbf)
3. MEASURE TORQUE CONVERTER CLUTCH SLEEVE
RUNOUT
(a) Temporarily mount the torque converter clutch to the drive
plate. Set up a dial indictor.
Maximum runout: 0.30 mm (0.0118 in.)
If runout exceeds 0.30 mm (0.0118 in.), try to correct by reori-
enting the installation of the torque converter clutch.
If excessive runout cannot be corrected, replace the torque
converter clutch.
HINT:
Mark the position of the torque converter clutch to ensure cor-
rect installation.
(b) Remove the torque converter clutch.

AT05Y±01
D00910
Q07487
SST
AT0103
± AUTOMATIC TRANSMISSIONATF TEMPERATURE SENSOR
AT±5
1953 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
ATF TEMPERATURE SENSOR
ON±VEHICLE REPAIR
CAUTION:
When working with FIPG material, you must observe the follow-
ing items.

Using a razor blade and gasket scraper, remove all the old
FIPG material from the gasket surfaces.

Thoroughly clean all components to remove all the loose
material.

Clean both sealing surfaces with a non±residue solvent.

Apply FIPG in an approx. 1 mm (0.04 in.) wide bead along
the sealing surface.

Parts must be assembled within 10 minutes of application.
Otherwise, the FIPG material must be removed and reap-
plied.
1. REMOVE DRAIN PLUG WITH GASKET AND DRAIN
AT F
2. REMOVE OIL PAN
NOTICE:
Some fluid will remain in the oil pan.
(a) Remove the 19 bolts.
(b) Install the blade of SST between the transmission case
and oil pan, cut off applied sealer, and remove the oil pan.
SST 09032±00100
NOTICE:
When removing the oil pan, be careful not to damage the oil
pan flange.
3. EXAMINE PARTICLES IN PAN
Remove the magnets and use them to collect steel particles.
Carefully look at the foreign matter and particles in the pan and
on the magnets to anticipate the type of wear you will find in the
transmission.
Steel (magnetic) ... bearing, gear and clutch plate wear
Brass (non±magnetic) ... bushing wear

D00752
D00753
D00909
D00916
D00909
AT±6
± AUTOMATIC TRANSMISSIONATF TEMPERATURE SENSOR
1954 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. REMOVE OIL STRAINER
NOTICE:
Be careful as some fluid will come out of the oil strainer.
(a) Remove the 4 bolts and oil strainer.
(b) Remove the 3 gaskets from the oil strainer.
5. REMOVE SOLENOID WIRING WITH ATF TEMPERA-
TURE SENSOR
(a) Disconnect the ATF temperature sensor.
(b) Remove the bolt and clamp.
(c) Disconnect the 7 connectors from the solenoid valves.
(d) Remove the bolt and pull out the solenoid connector.
6. INSTALL SOLENOID WIRING WITH ATF TEMPERA-
TURE SENSOR
(a) Install the solenoid connector with the bolt.
Torque: 5.4 N´m (55 kgf´cm, 48 in.´lbf)
(b) Connect the 7 connectors to the solenoid valves.
(c) Install the clamp with the bolt.
Torque: 6.4 N´m (65 kgf´cm, 56 in.´lbf)
(d) Connect the ATF temperature sensor.

D00753
D00752
D00912
D01917
Seal Breadth 2 ~ 3 mm (0.08 ~ 0.12 in.)
D00910
ºAº
± AUTOMATIC TRANSMISSIONATF TEMPERATURE SENSOR
AT±7
1955 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
7. INSTALL OIL STRAINER
(a) Install 3 new gaskets.
(b) Install the oil strainer with the 4 bolts.
Torque: 10 N´m (100 kgf´cm, 7 ft´lbf)
8. INSTALL OIL PAN
(a) Install the 3 magnets in the indications of the oil pan.
(b) Remove any packing material and be careful not to drop
oil on the contacting surfaces of the transmission case
and oil pan.
(c) Apply FIPG to the oil pan.
FIPG:
Part No. 08826 ± 00090, THREE BOND 1281 or
equivalent
(d) Install the oil pan with the 19 bolts.
Torque: 7.4 N´m (75 kgf´cm, 65 in.´lbf)
HINT:
Replace the only ºAº bolt with a new one.
9. INSTALL DRAIN PLUG WITH NEW GASKET
Torque: 20 N´m (205 kgf´cm, 15 ft´lbf)
10. FILL FLUID AND CHECK FLUID
(See page DI±318)

AT05Z±01
D00754
D01741
Spring Check Ball Body AT±8
± AUTOMATIC TRANSMISSIONVALVE BODY ASSEMBLY
1956 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
VALVE BODY ASSEMBLY
ON±VEHICLE REPAIR
CAUTION:
When working with FIPG material, you must observe the follow-
ing items.

Using a razor blade and gasket scraper, remove all the old
FIPG material from the gasket surfaces.

Thoroughly clean all components to remove all the loose
material.

Clean both sealing surfaces with a non±residue solvent.

Apply FIPG in an approx. 1 mm (0.04 in.) wide bead along
the sealing surface.

Parts must be assembled within 10 minutes of application.
Otherwise, the FIPG material must be removed and reap-
plied.
1. REMOVE DRAIN PLUG WITH GASKET AND DRAIN
AT F
2. REMOVE OIL PAN (See page AT±5)
3. EXAMINE PARTICLES IN PAN (See page AT±5)
4. REMOVE OIL STRAINER (See page AT±5)
5. REMOVE SOLENOID WIRING WITH ATF TEMPERA-
TURE SENSOR (See page AT±5)
6. REMOVE VALVE BODY
Remove the 21 bolts and valve body.
7. REMOVE CHECK BALL BODY AND SPRING
NOTICE:
Do not drop the check ball body and spring.

D00911
Shift Solenoid
Valve SLN
Shift Solenoid
Valve SLTShift Solenoid
Valve S1 Shift Solenoid
Valve S3
Shift Solenoid
Valve SLU
Shift Solenoid Valve S2 Shift Solenoid Valve S4
D01741
Spring Check Ball Body
D00913
Pin
± AUTOMATIC TRANSMISSIONVALVE BODY ASSEMBLY
AT±9
1957 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
8. REMOVE SOLENOID VALVE
(a) Remove the 3 bolts and shift solenoid valve No.1, No.2
and No.3.
(b) Remove the 2 bolts, oil guide plate, lock plate, shift sole-
noid valve SLN and No.4.
(c) Remove the 6 O±rings from each shift solenoid valve.
(d) Remove the bolt, lock plate and shift solenoid valve SLU
and SLT.
9. INSTALL SOLENOID VALVE
(a) Install the shift solenoid valve SLU and SLT and the lock
plate with the bolt.
Torque: 6.4 N´m (65 kgf´cm, 56 in.´lbf)
(b) Coat 6 new O±rings with ATF.
(c) Install the 6 O±rings to the each solenoid valve.
(d) Install the shift solenoid valve SLN, No.4, lock plate and
oil guide plate with the 2 bolts.
Torque: 10 N´m (100 kgf´cm, 7 ft´lbf)
(e) Install the shift solenoid valve No.1, No.2 and No.3 with
the 3 bolts.
Torque:
Shift solenoid valve No.1 and No.3:
6.4 N´m (65 kgf´cm, 56 in.´lbf)
Shift solenoid valve No.2:
10 N´m (100 kgf´cm, 7 ft´lbf)
10. INSTALL CHECK BALL BODY AND SPRING
11. INSTALL VALVE BODY
(a) Align the groove of the manual valve to pin of the lever.

D00754
A
CB
B
B
B
C
CA
DB
AT±10
± AUTOMATIC TRANSMISSIONVALVE BODY ASSEMBLY
1958 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(b) Install the 21 bolts.
Torque: 10 N´m (100 kgf´cm, 7 ft´lbf)
Bolt length:
Bolt A: 23 mm (0.91 in.)
Bolt B: 28 mm (1.10 in.)
Bolt C: 36 mm (1.42 in.)
Bolt D: 55 mm (2.17 in.)
12. INSTALL SOLENOID WIRING WITH ATF TEMPERA-
TURE SENSOR (See page AT±5)
13. INSTALL OIL STRAINER (See page AT±5)
14. INSTALL OIL PAN (See page AT±5)
15. INSTALL DRAIN PLUG WITH NEW GASKET
Torque: 20 N´m (205 kgf´cm, 15 ft´lbf)
16. FILL FLUID AND CHECK FLUID (See page DI±318)

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 (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.