2000 LEXUS GS400 warning

I04035
From Back Side
1 2 3
I04044
I04045
Wire Harness Side
± BODY ELECTRICALTURN SIGNAL AND HAZARD WARNING SYSTEM
BE±57
2358 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT TURN SIGNAL SWITCH CIRCUIT
Connector connected:
Connect the wire harness side connector to the combination
switch and inspect the connector form the back side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundIgnition switch ON and turn signal switch NeutralNo voltage
1 ± GroundIgnition switch ON and turn signal switch LeftBattery positive voltage e 0 V
3 ± GroundIgnition switch ON and turn signal switch RightBattery positive voltage e 0 V
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
4. INSPECT HAZARD WARNING SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
Switch OFF7 ± 10Continuity
Switch ON7 ± 8Continuity
Illumination circuit2 ± 3Continuity
If continuity is not as specified, replace the switch.
5. INSPECT HAZARD WARNING SWITCH CIRCUIT
(See page DI±814)
Disconnect the switch connector and inspect the connection on
the wire harness side, as shown.
Tester connectionConditionSpecified condition
8 ± GroundConstantContinuity
If circuit is not as specified, inspect the circuits connected to oth-
er parts.

I04046
Wire Harness Side BE±58
± BODY ELECTRICALTURN SIGNAL AND HAZARD WARNING SYSTEM
2359 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. INSPECT TURN SIGNAL FLASHER CIRCUIT
Disconnect the connector from the combination switch and in-
spect the connector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantContinuity
3 ± GroundConstantContinuity
5 ± GroundTurn signal switch RIGHT or OFFNo continuity
5 ± GroundTurn signal switch LEFTContinuity
6 ± GroundTurn signal switch LEFT or OFFNo continuity
6 ± GroundTurn signal switch RIGHTContinuity
7 ± GroundConstantContinuity
8 ± GroundHazard warning switch OFFNo continuity
8 ± GroundHazard warning switch ONContinuity
1 ± GroundIgnition switch LOCK or ACCNo voltage
1 ± GroundIgnition switch ONBattery positive voltage
4 ± GroundConstantBattery positive voltage
If circuit is as specified, replace the relay.
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)

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)

I04253

Meter Circuit Plate ± 2
Combination Meter ECU
SLIP Indicator
TRAC OFF Indicator
Window Washer Level Warning
ABS Warning
VSC Warning
Brake Fluid Level Warning
ECT SNOW Indicator
Low Oil Pressure Warning
ECT PWR Indicator
Discharge Warning
CRUISE MAIN Indicator
Seat Belt Warning
Rear Light Indicator
Headlight Leveling Indicator
SRS Warning
Open Door Warning
Fog Light IndicatorA/T 2 Indicaor
Engine Oil Level Indicator
Malfunction Indicator
Fuel Level Indicator
Headlight Indicator (USA)
Taillight Indicator (CANADA) ODO/
TRIP
Display
PanelIG+
SLIP
TRC OFF
WASHER
ABS
VSC
BRAKE
ECT SNOW
OIL P
ECT PWR
CHARGE
CRUISE
SEAT BELT
Rr LIGHT
HEAD LVL
AIRBAG
SRS +B
DOOR
FR FOG
COM1
SEG30
TEST1
TEST2
TEST3
GroundCHECK
ENG
IG+
FUEL
IG+
BEAM±
BEAM+ SRS +BTAIL A/T R
A/T L
A/T N
A/T D
OIL LVLDIM+
A/T 2
A/T 3
A/T 4F12
A/T PF11
F10
F9
F8
F5
F4
F2
F1
C7
C5
C3
D12
D8 E11
E10
E9
E8
E7
E6
J1
J33
D6
D4Hi±Beam Indicator
D2 E20
E19
E18
E17
E16
E15
E14
E13
E12
E3
E1 E5
E4A/T 3 Indicaor
A/T 4 Indicaor
A/T P Indicaor
A/T R Indicaor
A/T L Indicaor
A/T N Indicaor
A/T D Indicaor
T1
T2
T3
T4
~~
D10 BE±88
± BODY ELECTRICALCOMBINATION METER
2389 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)