LEXUS GS400 2000 Service Repair Manual

I04072
4 3
I04073
54
I04074
1
54 2
I04076
Wire Harness Side BE±78
± BODY ELECTRICALWIPER AND WASHER SYSTEM
2379 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. INSPECT WIPER MOTOR OPERATION
High speed:
Connect the positive (+) lead from the battery to terminal 3 and
the negative (±) lead to terminal 4, check that the motor oper-
ates at high speed.
If operation is not as specified, replace the motor.
5. INSPECT WIPER MOTOR OPERATION
Stopping at stop position:
(a) Operate the motor at low speed and stop the motor opera-
tion anywhere except at the stop position by disconnect-
ing positive (+) lead from terminal 5.
(b) Connect terminals 1 and 5.
(c) Connect the positive (+) lead from the battery to terminal
2 and negative (±) lead to terminal 4, check that the motor
stops running at the stop position after the motor operates
again.
If operation is not as specified, replace the motor.
6. INSPECT WIPER MOTOR CIRCUIT
Connector disconnected:
Disconnect the connector from the motor and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
4 ± GroundConstantContinuity
2 ± GroundIgnition switch LOCK or ACCNo voltage
2 ± GroundIgnition switch ONBattery positive voltage
If circuit is not as specified, inspect the circuits connected to oth-
er parts.

I01272
2
1
I04077
Wire Harness Side
± BODY ELECTRICALWIPER AND WASHER SYSTEM
BE±79
2380 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
7. INSPECT WASHER MOTOR OPERATION
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.
8. INSPECT WASHER MOTOR CIRCUIT
Connector disconnected:
Disconnect the connector from the motor and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundIgnition switch ONBattery positive voltage
If circuit is not as specified, inspect the power source, wire har-
ness and wiper switch.

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)

BE0HI±03
I04248
Connector ºUºConnector ºAº Connector ºBº
Combination Meter Wiring Circuit Connectors
Connector ºAº Connector ºBº Connector ºUº BE±82
± BODY ELECTRICALCOMBINATION METER
2383 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
CIRCUIT

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)

I04251

Combination Meter Wiring Circuit ± 2
Left Turn Indicator
Right Turn Indicator
Hi±beam Indicator
SRS Warning
Washer Level Indicator
Headlight leveling
Indicator
Malfunction
Indicator
VSC Warning
ABS Warning
VSC OFF Indicator
SLIP Indicator IG+IG+ IG+
IG+
IG+
IG+Combination Meter ECU
A14 A15 A16 A13 A12 B18 A10 to HEAD FuseB15B3B2
A7
B12Headlight Dimmer Switch
Airbag Sensor Assembly
Washer Fluid Level
Warning Switch
Healight Leveing
Contorl ECU
ECM
ABS, TRAC and
VSC ECU Turn Singal
Flasher RelayODO/TRIP Switch
RESET Switch to Combination Meter ECU
to Combination Meter ECUU8
U3
U10
U9
U4
SRS +B BE±84
± BODY ELECTRICALCOMBINATION METER
2385 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

Clock (Passenger seat belt warning light)
Tilt and telescopic ECU
Fuel main sender gauge
Fuel sub sender gauge
ABS, TRAC and VSC ECU (Speed signal)
Speed control unit
Headlight dimmer switch
Ground
Window washer level warning switch
Body control No.2 ECU
ECM
ABS, TRAC and VSC ECU (VSC warning light)
ABS, TRAC and VSC ECU (SLIP warning light)
ABS, TRAC and VSC ECU (TRAC OFF warning light)
ABS, TRAC and VSC ECU (ABS warning light)
ABS, TRAC and VSC ECU (Brake warning light)
GAUGE fuse
Turn signal flasher (Left turn side)
Turn signal flasher (Right turn side)
Light control rheostat (+B)
Light control rheostat (Signal)
Light control rheostat (Ground)
PANEL fuse
Airbag sensor assembly
MPX+B fuse
DOME+B fuse
HEAD±RH fuse
Igniter
Headlight beam leveling control ECU
Ground
Telltale light assembly (IG+)
Telltale light assembly (ODO/TRIP switch)
Telltale light assembly (Right turn signal)
Telltale light assembly (RESET switch)
Telltale light assembly (Left turn signal)
GroundWiring connector side No.1
1
1
2
3
4
5
6
7
8
10
11
12
13
14
15
16
17
1 1
1
2
3
4
5
6
9
12
13
14
15
16
18
22
1 1
1
3
4
8
9
10 U B A
± BODY ELECTRICALCOMBINATION METER
BE±85
2386 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

I04249

Combination Meter ECU Plate
Connector ºCºConnector ºDº
Connector ºEº
Connector ºJº Connector Gº
Connector ºFº
Connector ºTº Connector
ºOº, ºPº, ºQº, ºRº Connector ºLº Connector ºKºConnector ºDº Connector ºEº Connector ºJº Connector ºCºConnector ºFºConnctor ºGº Connector ºKº Connector ºLº
Connector ºTº
Q3 Q4Q1
Q2
O2
O1 O4O3
R3 R2R1
R4 P1
P2P3 P4
1 13 1 13 1 20
1 12133
112 112
Buzzer BE±86
± BODY ELECTRICALCOMBINATION METER
2387 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)