Page 35 of 1111
I02376
GS300:
3
I02375
GS400:
3
± AIR CONDITIONINGCOMPRESSOR AND MAGNETIC CLUTCH
AC±35
2720 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. MAKE THESE VISUAL CHECKS:
(a) Leakage of grease from the clutch bearing.
(b) Signs of oil on the pressure plate or rotor.
6. INSPECT MAGNETIC CLUTCH BEARING FOR NOISE
(a) Start engine.
(b) Check for abnormal noise from the compressor when the
A/C switch is OFF.
If abnormal noise is being emitted, replace the rotor of magnetic
clutch.
7. INSPECT MAGNETIC CLUTCH OPERATION
(a) Disconnect the connector.
(b) Connect the positive (+) lead from the battery to terminal
3 and the negative (±) lead to the body ground.
(c) Check that the magnetic clutch is energized.
If operation is not as specified, replace the magnetic clutch.
Page 38 of 1111
AC0WV±01
I02381
I02380
I02382
AC±38
± AIR CONDITIONINGCOMPRESSOR AND MAGNETIC CLUTCH
2723 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. RUN ENGINE AT IDLE SPEED WITH A/C ON FOR
APPROX. 10 MINUTES
2. STOP ENGINE
3. DISCONNECT NEGATIVE (±) TERMINAL CABLE
FROM BATTERY
4. DISCHARGE REFRIGERANT FROM REFRIGERATION
SYSTEM
5. REMOVE ENGINE UNDER COVER
6. REMOVE DRIVE BELT
(See page AC±15)
7. GS400:
DISCONNECT DISCHARGE HOSE
Remove the nut and disconnect the discharge hose.
NOTICE:
Cap the open fitting immediately to keep moisture or dirt
out of the system.
8. GS400:
REMOVE SUCTION HOSE
Remove the nut, bolt and suction hose.
NOTICE:
Cap the open fitting immediately to keep moisture or dirt
out of the system.
9. GS300:
DISCONNECT DISCHARGE AND SUCTION HOSES
Remove the 2 nut and disconnect the both hoses.
NOTICE:
Cap the open fitting immediately to keep moisture or dirt
out of the system.
Page 43 of 1111
AC0WX±01
N04963
Dial Indicator
± AIR CONDITIONINGCOMPRESSOR AND MAGNETIC CLUTCH
AC±43
2728 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REASSEMBLY
Reassembly is in the reverse order of disassembly
(See page AC±40).
AFTER REASSEMBLY, CHECK MAGNETIC CLUTCH
CLEARANCE
(a) Set the dial indicator to the pressure plate of the magnetic
clutch.
(b) Connect the magnetic clutch lead wire to the positive (+)
terminal of the battery.
(c) Check the clearance between the pressure plate and ro-
tor when connecting the negative (±) terminal to the bat-
tery.
Standard clearance:
0.5 ± 0.15 mm (0.020 ± 0.0059 in.)
If the clearance is not within the standard clearance, adjust the
clearance using shims to obtain the standard clearance.
Shim thickness:
0.1 mm (0.004 in.)
0.3 mm (0.012 in.)
0.5 mm (0.020in.)
Page 80 of 1111

AC0Y2±01
I03743
1 2 AC±80
± AIR CONDITIONINGCONDENSER FAN
2765 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
CONDENSER FAN
ON±VEHICLE INSPECTION
1. INSPECT CONDENSER FAN OPERATION
Inspect the fan operation, as shown in the chart below.
Test conditions:
Ignition switch ON
Blower speed control switch position ºHIº
Temperature control dial at ºMAX. COOLº
Install manifold gauge setº
A/C switch ON
ConditionFan operation (Fan speed)
Engine coolant temperature
91°C (196 °F) or belowRotate (Low speed)
Engine coolant temperature
100°C (212 °F) or aboveRotate (High speed)
Refrigerant pressure is less than
1,520 kPa (15.5 kgf´cm2, 220 psi)Rotate (Low speed)
Refrigerant pressure is 1,520 kPa
(15.5 kgf´cm2, 220 psi) or aboveRotate (High speed)
If operation is not as specified, proceed to the next inspection.
2. INSPECT CONDENSER FAN MOTOR OPERATION
(a) Disconnect the fan connector.
(b) Connect the positive (+) lead from the battery to terminal
2 and negative (±) lead to terminal 1 then check that motor
operations smoothly.
If operation is not as specified, replace the fan mo-
tor.
If operation is as specified, check the pressure
switch, cooling fan relays and engine coolant temp.
switch.
Page 99 of 1111

AT061±01
D01925
ACC
EP1KLS+
SLS+
Z16909
4 (+)
3 (±)
Z16910
4 (+)
3 (±)
AT±12
± AUTOMATIC TRANSMISSIONSHIFT LOCK SYSTEM
1960 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT SHIFT LOCK CONTROL ECU
Using a voltmeter, measure the voltage at each terminal.
HINT:
Do not disconnect the ECU connector.
TerminalMeasuring ConditionSpecified Condition
(1) IG SW ACC and shift lever P position0 V
1 ± 10 (KLS ± E)(2) IG SW ACC and shift lever except P position7.5 ± 11V (about I second)
after 6 ± 9 V
4 10 (ACC E)(1) IG SW ON10 ± 14 V4 ± 10 (ACC ± E)(2) IG SW ACC10 ± 14 V
7 10 (P1 E)(1) Shift lever P position0 V7 ± 10 (P1 ± E)(2) Shift lever except P position10 ± 14 V
(1) IG SW ON and shift lever P position0 V
8 10 (SLSE)(2) IG SW ON and depress brake pedal or shift lever N position3 ± 6 V8 ± 10 (SLS ± E)(3) IG SW ON and release brake pedal or shift lever except P position0 V
(4) IG SW ACC and shift lever except P position3 ± 6 V
10 ± Ground (E ± Ground)ConstantContinuity
2. INSPECT KEY INTERLOCK SOLENOID
(a) Disconnect the solenoid connector.
(b) Using an ohmmeter, measure the resistance between ter-
minals 3 and 4.
Standard resistance: 12 ± 17 W
If the resistance value is not as specified, replace the solenoid.
(c) Touch the solenoid with your finger and check that the so-
lenoid operation can be felt when battery voltage is ap-
plied intermittently to terminals 3 and 4.
If the operation is not as specified, replace the solenoid.
Page 136 of 1111

BE01I±09
± BODY ELECTRICALBODY ELECTRICAL SYSTEM
BE±1
2302 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
BODY ELECTRICAL SYSTEM
PRECAUTION
HINT:
Take care to observe the following precautions when performing inspections or removal and replacement
of body electrical related parts.
1. HEADLIGHT SYSTEM
Halogen bulbs have pressurized gas inside and require special handling. They can burst if scratched
or dropped. Hold a bulb only by its plastic or metal case. Don't touch the glass part of a bulb with bare
hands.
When high voltage socket of discharge headlight is touched with the light control switch HEAD, high
voltage of 20,000 V is momentarily generated. This might lead to a serious accident.
Never connect the tester to the high voltage socket of discharge headlight for measurement, as this
leads to a serious accident because of high voltage.
When performing operation related to the discharge headlight, make sure to do it in the place with no
water of rain to prevent electric shock, with light control switch OFF, battery terminal removed, connec-
tor of light control ECU disconnected.
When performing operation related to the discharge headlight, make sure to do it after assembling has
been completely over and never light up without a bulb installed.
Do not light up the discharge headlight using another power source except vehicle's.
When there is a defect on the discharge headlight or any shock has been applied to it, replace the light
with a new one.
Even if the light operates normally, there is a possibility that the fail±safe function works.
2. SRS (SUPPLEMENTAL RESTRAINT SYSTEM)
The LEXUS GS300/ 400 is equipped with an SRS (Supplemental Restraint System) such as the driver airbag
and front passenger airbag. Failure to carry out service operation in the correct sequence could cause the
SRS to unexpectedly deploy during servicing, possibly leading to a serious accident. Before servicing (in-
cluding removal or installation of parts, inspection or replacement), be sure to read the precautionary notices
in the RS section.
3. COMBINATION METER SYSTEM
The cold cathode tube connectors (Connector ºKºand ºLº) in the combination meter are charged with high
voltage AC current when power is supplied, so do not touch them when they are charged.
Page 137 of 1111

BE±2
± BODY ELECTRICALBODY ELECTRICAL SYSTEM
2303 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. MICRO COMPUTER PRESET DRIVING POSITION SYSTEM
Power Seat Control System
Power Mirror Control System
Power Tilt and Telescopic Steering System
If the battery negative (±) terminal is disconnected, the preset driving positions stored in memory are erased,
so be sure to note the positions and reset them after the battery terminal is reconnected.
5. AUDIO SYSTEM
If the negative (±) terminal cable is disconnected from the battery, the preset AM, FM 1 and FM 2 sta-
tions stored in memory are erased, so be sure to note the stations and reset them after the negative
(±) terminal cable is reconnected to the battery.
If the negative (±) terminal cable is disconnected from the battery, the ºANTI±THEFT SYSTEMº will
operate when the cable is reconnected, but the radio, tape player and CD player will not operate. Be
sure to input the correct ID number so that the radio, tape player and CD player can be operated again.
6. MOBILE COMMUNICATION SYSTEM
If the vehicle is equipped with a mobile communication system, refer to precautions in the IN section.
Page 139 of 1111

BE0GV±04
I04110
(b) (d)
Slowly
RetractedRetracted
More Quickly
I04111
Wire Harness Side
± BODY ELECTRICALELECTRIC TENSION REDUCER SYSTEM
BE±105
2406 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT TENSION REDUCER SOLENOID OPERA-
TION
(a) Connect the positive (+) lead from the battery to terminal
1, and negative (±) lead to terminal 2.
(b) Pull the belt upward and check that the belt is slowly re-
tracted when released.
(c) Disconnect the lead from the battery.
(d) Pull the belt upward and check that the belt is retracted
more quickly when released than in (b).
HINT:
Do not tilt the retractor.
If the operation is not as specified, replace the front seat outer
belt assembly.
2. INSPECT TENSION REDUCER SOLENOID CIRCUIT
Disconnect the tension reducer solenoid connector and inspect
the connector on wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundBuckle switch position
OFF (belt unfastened)No continuity
2 ± GroundBuckle switch position
ON (belt fastened)Continuity
1 ± GroundIgnition switch ACC or LOCKNo voltage
1 ± GroundIgnition switch ONBattery positive voltage
If the circuit is specified, replace the front seat outer belt assem-
bly.
If the circuit is not as specified, inspect the circuits connected
to other parts.