2000 LEXUS GS400 coolant temperature

AC0WA±01
I03811
Smog Ventilation
Sensor
No. 2 Cooling Fan Relay
(Marking: FAN NO.2) No. 3 Cooling Fan Relay
(Marking: FAN NO.3)
CompressorMagnetic Clutch Relay
(Marking A/C COMP)
Condenser
Ambient Temperature Sensor Condenser Fan
Engine Coolant Temperature
(ECT) Switch
Air Inlet Servomotor
Blower Motor
Air Outlet Servomotor A/C Amplifier
EvaporatorSolar Sensor A/C Control Assembly
Electrical Multi Vision
(Built in A/C Control Assembly)
Expansion Valve
Air Refiner Filter
Blower Motor Control
Relay Evaporator Temperature
Sensor
Heater Radiator
Air Mix Servomotor
(Driver Side) Air Mix Servomotor
(Passenger Side)Room Temperature
Sensor
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±13
2698 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
LOCATION

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.

AC0XX±01
I05028
AC±92
± AIR CONDITIONINGENGINE COOLANT TEMPERATURE (ECT) SWITCH
2777 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
ENGINE COOLANT
TEMPERATURE (ECT) SWITCH
REMOVAL
1. REMOVE ENGINE UNDER COVER
2. DRAIN ENGINE COOLANT FROM RADIATOR
HINT:
It is not necessary to drain out all coolant
3. REMOVE ECT SWITCH
(a) Disconnect the connector.
(b) Remove the ECT switch.
Torque: 7.4 N´m (75 kgf´cm, 65 in.´lbf)
(c) Remove the O±ring from ECT switch.
HINT:
At the time of installation, please refer to the following item.
Lubricate a new O±ring with soapy water and install the switch.

AC0XY±01
P01924
Ohmmeter
± AIR CONDITIONINGENGINE COOLANT TEMPERATURE (ECT) SWITCH
AC±93
2778 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
INSPECT ECT SWITCH
(a) Using an ohmmeter, check that no continuity exists be-
tween the terminals when the coolant temperature is
above 100 °C (212 °F).
If continuity exists, replace the switch.
(b) Using an ohmmeter, check that continuity exists between
the terminals when the coolant temperature is below
91 °C (196 °F).
If there no continuity exists, replace the switch.

AC0XZ±01
AC±94
± AIR CONDITIONINGENGINE COOLANT TEMPERATURE (ECT) SWITCH
2779 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSTALLATION
Installation is in the reverse order of removal (See page AC±92).

I04250

Combination Meter Wiring Circuit ± 1
:Speedometer
:Tachometer
:Fuel Receiver Gauge
:Engine Coolant
Temperature
Receiver Gauge
Speed Control Unit
CLOCK
to GAUGE Fuse
to MPX±B Fuse
to SRS Fuse
Tilt and Telescopic ECU
Body ECU NO.2ECM (GS400)
Ignitor (GS300)
Fuel Main Sender GaugeGround
Fuel Sub Sender Gauge
Light Control Rheostat
Illuminations
ABS, TRAC and VSC ECU
ABS, TRAC and VSC ECU Speed Signal Passenger seat
belt warning
Rr LIGHTS
SEAT BELT
OIL PRESS
OIL LEVEL
DOOR IG+
SRS +BA/T P
A/T R
A/T N
A/T D
A/T 4
A/T 3
A/T 2
A/T L
CRUISE MPX+BIG+IG+
5V
+B
to ECUto
PANEL
Fuse B4
B5
B6
B9
A5
A17A3A8 B16
LCDECU S
T
F
E
Power Source
Brake
Buzzer A11A2 A1 A6
B1
B13
B14A4
B22 ECU
ECU
ECU
S
T
F
E
CHARGE
FUEL LVL
ECT PWR
ECT SNOW TAIL or HEAD
Ground IG+IG+ IG+ IG+
+B
± BODY ELECTRICALCOMBINATION METER
BE±83
2384 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

I04252
Engine
Coolant
Temperature
Receiver
Gauge
Tachometer
Speedometer
Fuel
Receiver
GaugeRight Turn Indicator Left Turn Indicator
ODO/TRIP Switch
RESET Switch TECOS+
TESIN+
TECOS± TESIN±
TACOS+
TASIN±
TASIN+
TACOS±
SPCOS±
SPSIN+
SPSIN±
SPCOS+
FUCOS±
FUSIN+TURN L
Power
Earth
TURN R
ODO/TRIP
RESET
HEAT±
Signal
Earth
Thermistor
SRS +B
C/C ±
C/C +
HEAT±
SRS +B Power
Earth O1
O2
O3
O4
P1
P2
P3
P4
Q1
Q2
Q3
Q4
R1
R2
R3G2 G1
G3
G4
G5
G6
G7
G8
L1
L2
L3
L4
L8
L12
K1
K3
K4
R4FUSIN±
FUCOS+C/C ±
C/C +K8
K12 Combination Meter ECU
Meter Circuit Plate ± 1
± BODY ELECTRICALCOMBINATION METER
BE±87
2388 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

BE0HJ±08
I04254
Meter Glass Decoration Plate Fuel Receiver Gauge
and Engine Coolant
Temperature Gauge SpeedometerTachometer
Cold Cathode Tube with PlateMeter Body ECU Plate Meter Cover
Buzzer
Telltale Light Assembly Connector
Clips
± BODY ELECTRICALCOMBINATION METER
BE±89
2390 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMPONENTS