Page 24 of 1111
I01386
AC±4
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
2689 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. INSPECT REFRIGERANT PRESSURE WITH MAN-
IFOLD GAUGE SET
This is a method in which the trouble is located by using a man-
ifold gauge set. Read the manifold gauge pressure when these
conditions are established.
Test conditions:
Temperature at the air inlet with the switch set
at RECIRC is 30 ± 35 °C (86 ± 95 °F)
Engine running at 2,000 rpm
Blower speed control switch at ºHIº position
Temperature control dial on ºCOOLº position
HINT:
It should be noted that the gauge indications may vary slightly
due to ambient temperature conditions.
(1) Normally functioning refrigeration system.
Gauge reading:
Low pressure side:
0.15 ± 0.25 MPa (1.5 ± 2.5 kgf/cm
2)
High pressure side:
1.37 ± 1.57 MPa (14 ± 15 kgf/cm
2)
Page 98 of 1111
AT060±01
D01091
Shift Lock Control ECU Shift Lock Override ButtonKey Interlock Solenoid
Stop Light Switch
± AUTOMATIC TRANSMISSIONSHIFT LOCK SYSTEM
AT±11
1959 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
SHIFT LOCK SYSTEM
LOCATION
Page 107 of 1111
D01078
D01080
D01082
D01083
D01084
AT±20
± AUTOMATIC TRANSMISSIONFLOOR SHIFT ASSEMBLY
1968 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
14. REMOVE SHIFT LOCK CONTROL UNIT ASSEMBLY
(a) Remove the shift lock control unit assembly from the shift
lever plate.
(b) Push the shift lock solenoid link lightly, turn and remove
it.
(c) Remove the compression spring.
(d) Remove the slotted spring pin and separate the shift lock
solenoid link.
15. REMOVE SHIFT LEVER SUB±ASSEMBLY
(a) Using a pin punch and hammer, drive out the pin.
(b) Remove the shift lever sub±assembly.
(c) Remove the shift lever nut from the shift lever sub±as-
sembly.
16. REMOVE CONTROL LEVER, SPACER AND CON-
TROL SHAFT
(a) Remove the nut.
(b) Remove the 2 spacers and control shaft from the shift le-
ver plate.
(c) Disconnect the shift lever boot from shift lever plate.
(d) Remove the control lever.
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 142 of 1111

BE0GT±03
I04112
6
I04113
I04114
Wire Harness Side
Connector ºAº Connector ºBº
I01200
2 1
35
2 5
1 3
BE±108
± BODY ELECTRICALDEFOGGER SYSTEM
2409 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT DEFOGGER TIMER OPERATION
(a) Connect the positive (+) lead from the voltmeter to termi-
nal 6 of body ECU No.1 connector and negative (±) lead
to body ground.
(b) When the switch is OFF, the voltage should be approx.
12V.
(c) Turn the defogger switch ON and check that the indicator
lights up and that the voltage is less than 1 V.
(d) After 15 minutes, check that the switch is OFF and the
voltage is approx. 12 V.
If operation is not as specified, replace the switch.
2. INSPECT DEFOGGER SWITCH (in PANEL SWITCH)
CIRCUIT
Connector disconnected:
Disconnect the connector from the panel switch and inspect the
connector on wire harness side, as shown in the chart.
Tester connectionConditionSpecified condition
B10 ± GroundConstantContinuity
A1 ± GroundConstantBattery voltage
A2 ± GroundIgnition switch LOCKNo voltage
A2 ± GroundIgnition switch ACC or ONBattery voltage
If the circuit is not as specified, replace the switch.
3. INSPECT DEFOGGER RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
4. INSPECT DEFOGGER RELAY CIRCUIT
(See page DI±812 and BE±21)
Page 152 of 1111
I04117
15 16
2
Unlock
I04118
15 16
2
Lock BE±118
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
2419 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT POWER WINDOW MASTER SWITCH ILLU-
MINATION
(a) Set the window lock switch to the unlock position.
(b) Connect the positive (+) lead from the battery to terminal
15 and the negative (±) lead to terminal 16, and check that
all the illuminations light up.
(c) Connect the positive (+) lead from the voltmeter to termi-
nal 15 and negative (±) lead to terminal 2, and check that
the voltage meter needle indicates battery positive volt-
age.
(d) Set the window lock switch to the lock position, check that
all the passenger's power window switch illuminations go
out.
(e) Then, check that the voltage meter needle indicates no
voltage.
If operation is not as specified, replace the master switch.
Page 154 of 1111

I04123
I04119
2
3
I01200
2 1
35
2 5
1 3
I05474
1
2
BE±120
± BODY ELECTRICALPOWER WINDOW CONTROL SYSTEM
2421 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. INSPECT POWER WINDOW SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
AUTO3 ± 5Continuity
UP3 ± 6Continuity
OFF±No continuity
DOWN3 ± 4Continuity
If continuity is not as specified, replace the switch.
7. INSPECT POWER WINDOW SWITCH CIRCUIT
Passenger side: (See page DI±908)
Rear LH side: (See page DI±936)
Rear RH side: (See page DI±953)
8. INSPECT POWER WINDOW SWITCH ILLUMINATION
Connect the positive (+) lead from the battery to terminal 3 and
the negative (±) lead to terminal 2, and check that the indicator
light lights up.
If operation is not as specified, replace the switch.
9. INSPECT POWER MAIN RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
10. INSPECT POWER MAIN RELAY CIRCUIT
(See page BE±21)
11. Driver 's door:
INSPECT POWER WINDOW MOTOR OPERATION
(a) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 2, and check that
the motor turns clockwise.
Page 165 of 1111

BE0HR±04
I04116
I04132
I04133
42
± BODY ELECTRICALPOWER DOOR LOCK CONTROL SYSTEM
BE±131
2432 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. Master switch:
INSPECT DRIVER'S DOOR LOCK CONTROL SWITCH
CONTINUITY
Switch positionTester connectionSpecified condition
LOCK5 ± 16Continuity
OFF±No continuity
UNLOCK16 ± 17Continuity
If continuity is not as specified, replace the switch.
2. Master switch:
INSPECT DRIVER'S DOOR LOCK CONTROL SWITCH
CIRCUIT
(See page DI±866)
3. INSPECT PASSENGER'S DOOR LOCK CONTROL
SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
LOCK2 ± 3Continuity
OFF±No continuity
UNLOCK1 ± 2Continuity
If continuity is not as specified, replace the switch.
4. INSPECT PASSENGER'S DOOR LOCK CONTROL
SWITCH CIRCUIT
(See page DI±898)
5. INSPECT PASSENGER'S DOOR LOCK CONTROL
SWITCH ILLUMINATION
Connect the positive (+) lead from the battery to terminal 4 and
the negative (±) lead to terminal 2, and check that the indicator
light lights up.
If operation is not as specified, replace the switch.