Page 273 of 1111

BE0N6±04
I05587
2 5
I05580
2 5
Z08688
2 13
45 768 Wire Harness Side
± BODY ELECTRICALANTENNA
BE±225
2526 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. Auto Antenna Models:
INSPECT ANTENNA MOTOR
(a) Connect the positive (+) lead from the battery to terminal
2 and the negative (±) lead to terminal 5.
(b) Check that the motor turns (moves upward).
NOTICE:
These tests must be done quickly (within 3 ± 5 seconds) to
prevent the coil from burning out.
(c) Then, reverse the polarity, check that the motor turns the
opposite way (moves downward).
NOTICE:
These tests must be done quickly (within 3 ± 5 seconds) to
prevent the coil from burning out.
2. Auto Antenna Models:
INSPECT ANTENNA MOTOR CONTROL RELAY CIR-
CUIT
Disconnect the connector from the relay and inspect the con-
nector on wire harness side, as shown in the chart below.
Tester connectionConditionSpecified condition
7 ± GroundConstantContinuity
1 ± GroundIgnition switch ACC or ON,
and radio switch ON and OthersNo voltage
1 ± GroundIgnition switch ACC or ON,
and radio switch ON and AMBattery positive voltage
2 ± GroundIgnition switch ACC or ON,
and radio or tape or CD switch OFFNo voltage
2 ± GroundIgnition switch ACC or ON,
and radio or tape or CD switch ONBattery positive voltage
3 ± GroundConstantBattery positive voltage
4 ± GroundIgnition switch ACC or ON,
and radio switch ON and OthersNo voltage
4 ± Ground
Ignition switch ACC or ON,
and radio switch ON and
AM or FM (87.9 ± 96.0 MHz)
Battery positive voltage
5 ± GroundIgnition switch ACC or ON,
and radio switch OFFNo voltage
5 ± GroundIgnition switch ACC or ON,
and radio switch ONBattery positive voltage
Page 295 of 1111
BE02Q±15
I01376
ECM
Transponder Key Coil
Driver Side Junction Block
IGN Fuse Transponder Key Amplifier
± BODY ELECTRICALENGINE IMMOBILISER SYSTEM
BE±247
2548 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
LOCATION
The vehicle shown in this illustration is ºGS400º.
All components of ºGS300º other than the ones used for engine are same as ºGS400º.
Page 296 of 1111
BE0G8±09
I04266
1 2
BE±248
± BODY ELECTRICALENGINE IMMOBILISER SYSTEM
2549 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
INSPECTION TRANSPONDER KEY COIL CONTINUITY
Check that continuity exists between terminals 1 and 2.
If continuity is not as specified, replace the coil.
Page 353 of 1111

BE0H7±04
I04062
1 2
3 4
Pushed inFree
I04063
Wire Harness Side
I04064
w/ Rear spoiler type w/o Rear spoiler BE±70
± BODY ELECTRICALSTOP LIGHT SYSTEM
2371 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT STOP LIGHT SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
Switch pin free
(Pedal depressed)±No continuity
Switch pin pushed in
(Pedal released)1 ± 2Continuity
Switch pin free
(Pedal depressed)±No continuity
Switch pin pushed in
(Pedal released)3 ± 4Continuity
If continuity is not as specified, replace the switch.
2. INSPECT STOP LIGHT SWITCH CIRCUIT
(See page DI±839)
Disconnect the connector from the switch and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantBattery positive voltage
If circuit is not as specified, inspect the power source or wire
harness.
3. INSPECT HI±MOUNTED STOP LIGHT CONTINUITY
Using an ohmmeter, check that continuity exists between termi-
nals.
If continuity is not as specified, replace the light assembly or
bulb.
Page 357 of 1111

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.
Page 362 of 1111
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.
Page 364 of 1111
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)
Page 366 of 1111
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)