2000 LEXUS GS400 light

I04053
Wire Harness Side
± BODY ELECTRICALSTOP LIGHT SYSTEM
BE±71
2372 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. INSPECT HI±MOUNTED STOP LIGHT CIRCUIT
Disconnect the connector from the light and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantContinuity
If circuit is not as specified, inspect the power source or wire
harness.
5. INSPECT LIGHT FAILURE SENSOR
(See page DI±841 and BE±92)

BE023±07
I01357
Headlight Cleaner Relay Washer Tank

Headlight Cleaner Motor
Headlight Cleaner Switch
Headlight Cleaner Nozzle
Engine Room No.1
Junction Block

H±LP CLN H±Fuse
Ignition Switch
Driver Side Junction Block

WASHER Fuse
BE±72
± BODY ELECTRICALHEADLIGHT CLEANER SYSTEM
2373 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HEADLIGHT CLEANER SYSTEM
LOCATION
The vehicle shown in this illustration is ºGS400º.
All components of ºGS300º other than the ones used for engine are same as ºGS400º.

BE0HM±03
I04065
I01290
12
34 5 6 Wire Harness Side
e±6±1
I01687
1 2 3
4
5
± BODY ELECTRICALHEADLIGHT CLEANER SYSTEM
BE±73
2374 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT HEADLIGHT CLEANER SWITCH CONTINU-
ITY
Switch positionTester connectionSpecified condition
OFF±No continuity
ON2 ± 4Continuity
Illumination circuit5 ± 6Continuity
If continuity is not as specified, replace the switch.
2. INSPECT HEADLIGHT CLEANER SWITCH CIRCUIT
Disconnect the switch connector and inspect the connector on
wire harness side, as shown.
Tester connectionConditionSpecified condition
1 ± GroundHeadlight ONContinuity
1 ± GroundHeadlight OFFNo continuity
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
3. INSPECT HEADLIGHT CLEANER RELAY OPERATION
(a) Check that no continuity exists between terminals 2 and
5.
(b) Connect the positive (+) lead from the battery to terminals
1 and 5, and the negative (±) lead to terminal 3.
(c) Connect the negative (±) lead from the battery to terminal
4, and check that continuity exists between terminals 2
and 5 for 0.9 ± 1.1 seconds, then no continuity exists.
If operation is not as specified, replace the motor.

I04067
Wire Harness Side
I04068
2 1
I04069
Wire Harness Side BE±74
± BODY ELECTRICALHEADLIGHT CLEANER SYSTEM
2375 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. INSPECT HEADLIGHT CLEANER RELAY CIRCUIT
Disconnect the connector from the relay and inspect the con-
nector on wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± Ground
3 ± GroundConstantContinuity
4 ± GroundIgnition switch ON, light control switch in HEAD
and cleaner switch OFFNo continuity
4 ± Ground
Ignition switch ON, light control switch in HEAD
and cleaner switch ON or daytime running light
system operating
Continuity
1 ± GroundIgnition switch OFF or ACCNo voltage
1 ± GroundIgnition switch ONBattery positive voltage
5 ± GroundConstantBattery positive voltage
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
5. INSPECT HEADLIGHT CLEANER MOTOR OPERA-
TION
Connect the positive (+) lead from the battery to terminal 2 and
the negative (±) lead to terminal 1, check that the motor oper-
ates.
NOTICE:
These tests must be performed quickly (within 20 seconds) to
prevent the coil from burning out.
If operation is not as specified, replace the motor.
6. INSPECT HEADLIGHT CLEANER MOTOR CIRCUIT
Disconnect the connector from the cleaner motor and inspect
the connector on wire harness side, as shown.

± BODY ELECTRICALHEADLIGHT CLEANER SYSTEM
BE±75
2376 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)Tester connection
ConditionSpecified condition
2 ± GroundConstantContinuity
If circuit is not as specified, inspect the circuits connected to oth-
er parts.

BE0HH±07
I01359
Brake Master Cylinder

Brake Fluid Level
Warning Switch
Combination Meter
and Telltale Light
Assembly
Airbag Sensor Assembly Parking Brake Switch
Driver Side
Junction Block

GAUGE Fuse

SRS±B FuseIgnition Switch
ECM
Washer Tank

Washer Level
Warning Switch Engine Room No.1
Junction Block

MPX±B Fuse
Seat Belt Buckle Switch
Rheostat Light Control
ABS, TRAC and VSC ECU
Clock Assembly

Passenger Seat Belt
Waning Light
BE±80
± BODY ELECTRICALCOMBINATION METER
2381 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMBINATION METER
LOCATION
The vehicle shown in this illustration is ºGS400º.
All components of ºGS300º other than the ones used for engine are same as ºGS400º.

I01360
Fuel Tank

Fuel Main
Sender Gauge
Fuel Tank

Fuel Sub
Sender Gauge
Occupant Detection Sensor
(Passenger seat belt
warning sensor)
Engine Oil Level
Warning Sensor Engine Oil Level
Warning Sensor
Park/ Neutral
Position Switch
Low Oil Pressure
Warning Switch
Park/ Neutral
Position Switch
Low Oil Pressure
Warning Switch
GS300GS400 Light Failure Sensor
± BODY ELECTRICALCOMBINATION METER
BE±81
2382 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

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)