Throttle LEXUS GS400 2000 Service Owner's Guide

SF0NL±05
B09506
B01608
B01982
LEXUS
Hand±Held
Tester SF±32
± SFI (2JZ±GE)THROTTLE BODY
1498 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
THROTTLE BODY
ON±VEHICLE INSPECTION
1. REMOVE ENGINE COVER
Remove the 4 nuts and engine cover.
2. INSPECT SYSTEM OPERATION
(a) Check that the throttle linkage moves smoothly.
(b) Inspect the throttle control motor for operating sound.
(1) Turn the ignition switch ON.
(2) When turning the accelerator pedal position sensor
lever, check the running sound of the motor. Also,
check that there is no friction sound.
If operation is not as specified, check the throttle control motor,
wiring and ECM.
(c) Inspect the throttle position sensor and accelerator pedal
position sensor function.
(1) Connect the LEXUS hand±held tester to the DLC3.
(2) When turning the accelerator pedal position sensor
lever to the full±open position, check that the
throttle valve opening percentage (THROTTLE
POS) of the CURRENT DATA showns the standard
value.
Throttle valve opening percentage: 60 % or more
If operation is not as specified, check that the throttle position
sensor, accelerator pedal position sensor, wiring and ECM.
(d) Start the engine, and check that the Malfunction Indicator
Lamp (MIL) does not light up.
(e) Inspect the air assist system.
(1) Allow the engine to warm up to normal operating
temperature.

B09507
B01620
Ohmmeter3 (CL±)
4 (CL+)
1 (M+)
2 (M±)
B01942VCOhmmeter
E2
B01943
VC Ohmmeter
E2
± SFI (2JZ±GE)THROTTLE BODY
SF±33
1499 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(2) Turn the A/C switch ON and OFF, and check the idle
speed.
Idle speed (Transmission in neutral):
700 ± 50 rpm (A/C OFF)
750 ± 50 rpm (A/C ON)
NOTICE:
Perform inspection under condition without electrical load.
(3) With engine idling, pinch the air assist hose and
check that engine speed drops, and then returns
back up to idle speed.
If operation is not as specified, check the throttle body, wiring
and ECM.
(f) After checking the above (b) to (e), perform the diving test
and check that there is no sense of incongruity.
3. INSPECT THROTTLE CONTROL MOTOR
(a) Disconnect the throttle control motor connector.
(b) Using an ohmmeter, measure the resistance between ter-
minal 3 (CL±) and 4 (CL+).
Resistance: 4.2 ± 5.2 W at 20°C (68°F)
(c) Using an ohmmeter, measure the resistance between ter-
minal 1 (M+) and 2 (M±).
Resistance: 0.3 ± 100 W at 20°C (68°F)
If the resistance is not as specified, replace the throttle control
motor. (See page SF±37)
(d) Reconnect the throttle control motor connector.
4. INSPECT THROTTLE POSITION SENSOR
(a) Disconnect the throttle position sensor connector.
(b) Using an ohmmeter, measure the resistance between ter-
minals VC and E2.
Resistance: 1.2 ± 3.2 kW at 20°C (68°F)
If the resistance is not as specified, replace the throttle position
sensor. (See page SF±37)
(c) Reconnect the throttle position sensor connector.
5. INSPECT ACCELERATOR PEDAL POSITION SEN-
SOR
(a) Disconnect the accelerator pedal position sensor con-
nector.
(b) Using an ohmmeter, measure the resistance between ter-
minals VC and E2.
Resistance: 1.2 ± 3.2 kW at 20°C (68°F)
If the resistance is not as specified, replace the accelerator ped-
al position sensor. (See page SF±37)

SF±34
± SFI (2JZ±GE)THROTTLE BODY
1500 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(c) Reconnect the accelerator pedal position sensor connec-
tor.
6. REINSTALL ENGINE COVER
Reinstall the engine cover with the 4 nuts.

SF0NM±07
B09000
Intake Air Resonator
PCV Hose
PS Air Hose
Throttle Control
Motor ConnectorThrottle Body Bracket
Throttle Position Sensor Connector
Water Bypass HoseWater Bypass Hose Engine Wire ClampAccelerator Pedal Position
Sensor Connector
Accelerator Cable
21 (210, 15)
N´m (kgf´cm, ft´lbf) : Specified torqueThrottle Body
Engine Cover
B01947
CoverAccelerator Pedal Position Sensor
Washer Plate
Throttle Control Motor
Throttle Position Sensor Bracket
x 5
± SFI (2JZ±GE)THROTTLE BODY
SF±35
1501 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMPONENTS

SF0NN±05
B01615
B01616
Forward
Down±Side
Diagonal(2) (1)
SF±36
± SFI (2JZ±GE)THROTTLE BODY
1502 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. DRAIN ENGINE COOLANT
2. REMOVE ENGINE COVER
Remove the 4 nuts and engine cover.
3. REMOVE INTAKE AIR RESONATOR
4. REMOVE THROTTLE BODY BRACKET AND
THROTTLE BODY
(a) Disconnect the accelerator cable.
(b) Disconnect the throttle position sensor connector.
(c) Disconnect the throttle control motor connector.
(d) Disconnect the accelerator pedal position sensor con-
nector.
(e) Disconnect the engine wire clamp from the clamp bracket
of throttle body.
(f) Remove the 2 bolts and nut holding the throttle body to
the intake air connector.
Torque: 21 N´m (210 kgf´cm, 15 ft´lbf)
(g) Remove the 4 nuts and throttle body bracket.
Torque: 21 N´m (210 kgf´cm, 15 ft´lbf)
(h) Slightly slide the throttle body away from the intake air
connector.
NOTICE:
When putting up the throttle body, do not hold the motor
part.
(i) Disconnect the 2 water bypass hoses from the throttle
body, and remove the throttle body.
HINT:

At the time of installation, please refer to the following
items.

Connect the water bypass hose with its discrimination
mark downward.

Install the with its craw direction for (1) forward and down±
side diagonal (engine side about 45°) for (2).

SF0NO±05
B02816
B02692
30°(3)
(2)
B01951
Turn
(3)
(2)
± SFI (2JZ±GE)THROTTLE BODY
SF±37
1503 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REPLACEMENT
NOTICE:

To prevent deterioration, do not shock the throttle
position sensor and accelerator pedal position sen-
sor.

Mixing of the foreign objects may cause the gear lock-
ing, so thoroughly check that there is no stuck of any
foreign objects and clean up if any.
1. REPLACE THROTTLE POSITION SENSOR
(a) Remove the 2 set screws and throttle position sensor.
(b) Reinstall the throttle position sensor.
(1) Check that the throttle valve is under the condition
of the opener opening angle (about 3.5°).
(2) Install the sensor to the place where is at 30° ro-
tated to the right from the specified installation posi-
tion.
(3) Gradually turn sensor counterclockwise until it
touches the throttle valve shaft and temporarily
torque the 2 set screws.
(c) Adjust the throttle position sensor.
(1) Connect the throttle position sensor connector.
NOTICE:
At this time, do not connect the throttle control motor con-
nector.
(2) Connect the LEXUS hand±held tester or OBDII
scan tool to the DLC3.
(3) Turn the ignition switch ON.
NOTICE:
After turning the ignition switch ON, do not depress the ac-
celerator pedal.
(4) While reading the value of the throttle valve opening
percentage (THROTTLE POS) of the CURRENT
DATA, turn the throttle position sensor slowly to left
and set the sensor at the center value of the stan-
dard value, and then torque the screws.
Torque: 1.7 N´m (17.5 kgf´cm, 15 in.´lbf)
Standard throttle valve opening percentage:
14.8 ± 0.8 %

B01953
B01811
ºAº
Turn SF±38
± SFI (2JZ±GE)THROTTLE BODY
1504 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
NOTICE:
At the time of tightening the screw, as the sensor itself
tends to turn causing to slanting, check that it is within the
standard value after having finished the torque.
(5) Fully close the throttle valve with a screwdriver and
check that the value of the throttle valve opening
percentage (THROTTLE POS) of the CURRENT
DATA stays with the standard value.
Standard throttle valve opening percentage:
10 ± 14 %
If the throttle valve opening percentage is not as specified, re-
peat steps (4) through (5).
(6) Paint the sensor set screws.
(7) Turn the ignition switch OFF.
(8) Disconnect the LEXUS hand±held tester or OBDII
scan tool from the DLC3.
(9) Disconnect the throttle position sensor connector.
2. REPLACE THROTTLE CONTROL MOTOR
(a) Remove the throttle position sensor.
(b) Remove the throttle control motor.
(1) Disconnect the connector from the bracket.
(2) Remove the 5 screws, bracket and cover.
(3) Remove the 3 screws and throttle control motor.
(c) Reinstall the throttle control motor.
(1) Apply the grease thinly on the whole surface of the
gear teeth.
NOTICE:
Do not apply the grease other than specified because
grease has been already applied to the component to be re-
placed.
(2) Align the protrusions of the motor with the position-
ing pin holes of the throttle body.
(3) Rotate the motor to the direction marked with an ar-
row and temporarily install the set screw ºAº under
the condition that there is no wobbles in the motor
and the positioning pin.
(4) Tighten the 3 set screws.
Torque: 3.7 N´m (37.5 kgf´cm, 33 in.´lbf)

B01952
ºCº
ºBº
Bracket
B02943
1
Closely Affix
34
2
± SFI (2JZ±GE)THROTTLE BODY
SF±39
1505 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(5) Temporarily install the cover with the 2 screws ºBº
and ºCº.
NOTICE:
The grommet of motor not be caught.
(6) Tighten the 5 screws.
Torque: 1.7 N´m (17.5 kgf´cm, 15 in.´lbf)
(7) Connect the connector to the bracket.
(d) Reinstall and adjust the throttle position sensor. (See step
1)
3. REPLACE ACCELERATOR PEDAL POSITION SEN-
SOR
(a) Remove the accelerator pedal position sensor.
(1) Using a small screwdriver, pry the 4 stoppers of the
washer plate.
(2) Remove the 4 set bolts, washer plate and accelera-
tor pedal position sensor.
(b) Reinstall the accelerator pedal position sensor.
(1) Install the accelerator pedal position sensor to the
throttle body.
(2) Torque the 4 bolts in the order shown in the illustra-
tion through the washer plate.
Torque: 3.7 N´m (37.5 kgf´cm, 33 in.´lbf)
(3) Bend the stopper of the washer plate and closely af-
fix to the bolts.
(c) Inspect the accelerator pedal position sensor.
(1) Connect the accelerator pedal position sensor con-
nector.
(2) Connect the LEXUS hand±held tester or OBDII
scan tool to the DLC3.
(3) Turn the ignition switch ON.
NOTICE:
After turning the ignition switch ON, do not depress the ac-
celerator pedal.
(4) Check that the ACCEL POS #1 (VPA) voltage of the
CURRENT DATA shows the standard value.
Standard accelerator pedal position voltage:
0.3 ± 0.9 V
4. AFTER INSTALL THROTTLE BODY, INSPECT SYS-
TEM OPERATION (See page SF±32)

SF0NP±01
SF±40
± SFI (2JZ±GE)THROTTLE BODY
1506 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSTALLATION
Installation is in the reverse order of removal. (See page SF±36)

SF0OH±03
B01982
LEXUS
Hand±Held
Tester
B01568
Sound Scope
SF±72
± SFI (2JZ±GE)FUEL CUT RPM
1538 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
FUEL CUT RPM
INSPECTION
1. WARM UP ENGINE
Allow the engine to warm up to normal operating temperature.
2. CONNECT LEXUS HAND±HELD TESTER OR OBDII
SCAN TOOL
(a) Connect the LEXUS hand±held tester or OBDII scan tool
to the DLC3.
(b) Please refer to the LEXUS hand±held tester or OBDII
scan tool operator's manual for further details.
3. INSPECT FUEL CUT±OFF OPERATION
(a) Increase the engine speed to at least 3,000 rpm.
(b) Check for injector operating noise.
(c) Check that when the throttle lever is released, injector op-
eration noise stops momentarily and then resumes.
HINT:
Measure with the A/C OFF.
Fuel return rpm: 1,000 rpm
4. DISCONNECT LEXUS HAND±HELD TESTER OR
OBDII SCAN TOOL