2000 LEXUS GS400 fuse

BE0FY±09
I01377
Horn
Horn Switch Engine Room No.1
Junction Block

HORN Fuse
Theft Deterrent Horn
Engine Room No.2
Junction Block

Horn Relay
± BODY ELECTRICALHORN SYSTEM
BE±249
2550 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HORN 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.

BE19B±01
± BODY ELECTRICALTROUBLESHOOTING
BE±3
2304 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
TROUBLESHOOTING
PROBLEM SYMPTOMS TABLE
IGNITION SWITCH AND KEY UNLOCK WARNING SWITCH
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
Ignition Switch:
SymptomSuspect AreaSee page
Ignition switch is not set to each position.4. Ignition switch
5. Power source circuitBE±31
±
Key Unlock Warning Switch:
SymptomSuspect AreaSee page
Key unlock warning system does not operate.
(The buzzer does not sound when the driver's door is opened with
the ignition OFF and key inserted)1. Key Unlock Warning Switch
2. Door Courtesy Switch
3. Wire HarnessBE±31
BE±60
±
Key unlock warning system does not operate.
(The buzzer sounds when the ignition key is ACC or ON)1. Ignition Switch
2. Wire HarnessBE±31
±
HEADLIGHT AND TAILLIGHT SYSTEM:
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
HINT:
To inspect the bulb and light control ECU, replace them with the ones working normally and judge whether
they work normally or not.
SymptomSuspect AreaSee page
ºAutomatic light control systemº does not operate.
1. Automatic Light Control Sensor
2. Light Control Switch
3. Door Courtesy Switch
4. Wire Harness
5. Body No.2 ECUBE±37
BE±37
BE±60
±
DI±820
Auto turn±off system does not operate when the driver's door is
opened.1. Drivers Door Courtesy SwitchBE±60
Auto turn±off system:
Headlight and taillight do not come on.1. Body ECU No.2
2. Wire HarnessDI±820
±
Auto turn±off system:
Headlight and taillight stay on.1. Body ECU No.2
2. Wire HarnessDI±820
±
USA:
SymptomSuspect AreaSee page
Only one headlight comes on.
1. Bulb
2. *Light Control ECU
3. Wire Harness±
±
±
ºLO±Beamº does not light (All).
1. Headlight Control Relay
2. *Light Control ECU
3. Wire HarnessBE±37
±
±
ºLO±Beamº does not light (One side).
1. Bulb
2. H±LP L±LWR Fuse
3. H±LP R±LWR Fuse
4. *Light Control ECU
5. Wire Harness±
BE±21
BE±21
±
±
ºHI±Beamº does not light (All).1. Headlight Dimmer Switch
2. Wire HarnessBE±37
±

BE±4
± BODY ELECTRICALTROUBLESHOOTING
2305 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) ºHI±Beamº does not light (One side).
1. Bulb
2. H±LP L±UPR Fuse
3. H±LP R±UPR Fuse
4. Wire Harness±
BE±21
BE±21
±
ºFlashº does not light.
1. H±LP L±UPR Fuse
2. H±LP R±UPR Fuse
3. Headlight Dimmer Switch
4. *Light Control ECU
5. Wire HarnessBE±21
BE±21
BE±37
±
±
ºFlashº does not light.
1. Bulb
2. *Light Control ECU
3. Wire Harness±
±
±
Headlight does not come on.
1. Headlight Control Relay
2. Light Control Switch
3. *Light Control ECU
4. Wire HarnessBE±37
BE±37
±
±
Headlight does not come on.
1. Bulb
2. *Light Control ECU
3. Wire Harness±
±
±
Headlight flickers.
1. Bulb
2. *Light Control ECU
3. Wire Harness±
±
±
Headlight is dark.
1. Bulb
2. *Light control ECU
3. Wire Harness±
±
±
Only one taillight comes on.1. Bulb
2. Wire Harness±
±
Taillight does not come on.
(Headlight is normal)
1. TAIL Fuse
2. GAUGE Fuse
3. Taillight Control Relay
4. Light Failure Relay
5. Light Control Switch
6. Wire HarnessBE±21
BE±21
BE±37
BE±92
BE±37
±
Taillight does not come on.
(Headlight does not light)1. Light Control Switch
2. Wire HarnessBE±37
±
Rear combination light does not come on.
1. Light Failure Relay
2. Wire Harness
3. BulbBE±92
±
±
*: HID Type
CANADA:
SymptomSuspect AreaSee page
Only one headlight comes on.
1. Daytime Running Light No.2, 3, 4 Relay
2. Daytime Running Light Main Relay
3. Bulb
4. *Light Control ECU
5. Wire HarnessBE±37
BE±37
±
±
±
ºLO±Beamº does not light (All).
1. Headlight Control Relay
2. *Light Control ECU
3. Wire HarnessBE±37
±
±
ºLO±Beamº does not light (One side).
1. Bulb
2. H±LP L±LWR Fuse
3. H±LP R±LWR Fuse
4. *Light Control ECU
5. Wire Harness±
BE±21
BE±21
±
±

± BODY ELECTRICALTROUBLESHOOTING
BE±5
2306 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) ºHI±Beamº does not light (All).
1. Headlight Dimmer Switch
2. Daytime Running Light Main Relay
3. Wire HarnessBE±37
BE±37
±
ºHI±Beamº does not light (One side).
1. Bulb
2. H±LP L±UPR Fuse
3. H±LP R±UPR Fuse
4. Daytime Running Light No.3 Relay
5. Wire Harness±
BE±21
BE±21
BE±37
±
ºFlashº does not light.
1. Headlight Dimmer Switch
2. Daytime Running Light Main Relay
3. Wire HarnessBE±37
BE±37
±
Headlight does not come on.
1. Headlight Control Relay
2. Daytime Running Light Main Relay
3. Daytime Running Light No.2, 3, 4 Relay
4. Headlight Dimmer Switch
5. Light Control Switch
6. Wire Harness
7. *Light Control ECU
8. BulbBE±37
BE±37
BE±37
BE±37
BE±37
±
±
±
Headlight does not come on with light control switch in HEAD.
1. Light Control Switch
2. *Light Control ECU
3. Wire HarnessBE±37
±
±
Headlight does not go out with light control switch in OFF.
1. Headlight Control Relay
2. *Light Control ECU
3. Wire HarnessBE±37
±
±
Headlight flickers.
1. Bulb
2. *Light Control ECU
3. Wire Harness±
BE±37
±
Headlight is dark.
1. Bulb
2. *Light control ECU
3. Wire Harness±
±
±
Taillight does not come on with light control switch in TAIL.
1. Taillight Control Relay (Instrument Panel J/B)
2. Light Control Switch
3. Wire HarnessBE±37
±
±
Taillight does not go out with light control switch in OFF.
1. Taillight Control Relay
2. Light Control Switch
3. Wire HarnessBE±37
BE±37
±
Headlight does not come on with engine running and light control
switch in OFF.
1. ECU±B Fuse
2. GAUGE Fuse
3. Daytime Running Light Main Relay
4. Daytime Running Light No.2, 3, 4 Relay
5. Generator L Terminal
6. Parking Brake Switch
7. Wire HarnessBE±21
BE±21
BE±37
BE±37
DI±853
BE±92
±
*: HID Type

BE±6
± BODY ELECTRICALTROUBLESHOOTING
2307 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HEADLIGHT BEAM LEVEL CONTROL SYSTEM
SymptomSuspect AreaSee page
Beam axis is not controlled. (It is not initialized.)
Headlight Beam Level Control System does not operate.
1. ECU±IG Fuse
2. Headight Beam Level Control Actuator
3. Headlight Beam Level Control ECU
4. Wire Harness SideBE±21
BE±50
BE±50
±
Beam axis is not controlled. (It is initialized.)
Headlight Beam Level Control System does not operate.1. Height Control Sensor
2. Headlight Beam Level Control ECU
3. Wire Harness SideBE±50
BE±50
±
Controlled angle of head light is unusual.
(The angle is controlled.)
1. Height Control Sensor
2. Headlight Beam Level Control ECU
3. Headlights
4. Wire Harness Side±
BE±50
BE±3
±
Beam axis position is not stable during driving.
1. ABS System
2. Headlights
3. Wire HarnessDI±387
BE±3
±
FOG LIGHT SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
SymptomSuspect AreaSee page
Fog light does not light up with light control SW HEAD
(Headlight is normal.)
1. FOG Fuse
2. Fog Light Relay
3. Fog Light Switch
4. Wire Harness
5. Body No.2 ECUBE±21
BE±53
BE±53
±
±
Fog light does not light up with light control SW HEAD
(Headlight does not light).1.*1 Other Parts
2. Wire Harness±
±
Only one light does not light up.1. Bulb
2. Wire Harness±
±
*1: Inspect Headlight System
TURN SIGNAL AND HAZARD WARNING SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
SymptomSuspect AreaSee page
ºHazardº and ºTurnº do not light up.
1. GAUGE Fuse
2. TURN HAZ Fuse
3. Ignitioin Switch
4. Turn Signal Flasher Relay
5. Wire HarnessBE±21
BE±21
BE±31
BE±56
±
Hazard warning light does not light up.
(Turn is normal)1. Hazard Warning Switch
2. Wire HarnessBE±56
±
Turn signal does not light up.
(Hazard is normal)1. Turn Signal Switch
2. Wire HarnessBE±56
±
Turn signal does not light up in one direction.1. Turn Signal Switch
2. Wire HarnessBE±56
±
Only one bulb does not light up.1. Bulb
2. Wire Harness±
±

± BODY ELECTRICALTROUBLESHOOTING
BE±7
2308 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INTERIOR LIGHT SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
SymptomSuspect AreaSee page
All the lights do not come ON.1. DOME Fuse
2. Body ECU NO.2BE±21
±
The light does not come ON when the driver's door is opened.1. Driver's Door Courtesy Switch
2. Wire HarnessBE±60
±
The light does not come ON when the passenger's door is
opened.1. Passenger's Door Courtesy Switch
2. Wire HarnessBE±60
±
The light does not come on when the rear±right door is opened.1. Rear±Right Door Courtesy Switch
2. Wire HarnessBE±60
±
The light does not come on when the rear±left door is opened.1. Rear±Left Door Courtesy Switch
2. Wire HarnessBE±60
±
Only one of the bulbs comes ON.Bulb±
The illumination does not fade out when all the doors are closed.1. Courtesy Switch
2. Wire HarnessBE±60
±
The illumination does not fade out immediately when the ignition
switch is turned to ACC or ON within 15 seconds after all the
doors are closed.1. Ignition Switch
2. RADIO NO.2 Fuse
3. GAUGE Fuse
4. Wire HarnessBE±31
BE±21
BE±21
±
The illumination does not fade out immediately when all the doors
are locked within 15 seconds after they are closed.1. Door Unlock Detection Switch
2. Wire HarnessBE±131
±
Interior light does not light up.
(in front personal light)1. Bulb
2. Front Personal Light
3. Wire Harness±
BE±60
±
Front personal light does not light up.
1. Bulb
2. Front Personal Light
3. Wire Harness±
BE±60
±
Rear personal light does not light up.
1. Bulb
2. Rear Personal Light
3. Wire Harness±
BE±60
±
Vanity light does not light up.
1. Bulb
2. Vanity Light
3. Wire Harness±
BE±60
±
Luggage compartment light does not light up.
1. Bulb
2. Luggage Compartment Door Courtesy Switch
3. Wire Harness±
BE±60
±
Courtesy light does not light up.
1. Bulb
2. Door Courtesy Switch
3. Wire Harness±
BE±60
±

BE±8
± BODY ELECTRICALTROUBLESHOOTING
2309 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
BACK±UP LIGHT SYSTEM
SymptomSuspect AreaSee page
Back±Up Light does not light up.
1. GAUGE Fuse
2. Ignition Switch
3. Wire Harness
4. BulbBE±21
BE±31
±
±
Back±Up Light remains always on.1. Park/ Neutral Position Switch
2. Wire HarnessDI±372
±
Only one light does not light up.1. Bulb
2. Wire Harness±
±
STOP LIGHT SYSTEM
SymptomSuspect AreaSee page
Stop light does not light up.
1. STOP Fuse
2. Stop Light Switch
3. Light Failure Relay
4. Wire HarnessBE±21
BE±70
BE±92
±
Stop light always lights up.1. Stop Light Switc
2. Wire HarnessBE±70
±
Only one light always lights up.Wire Harness±
Only one light does not light up.1. Bulb
2. Wire Harness±
±
HEADLIGHT CLEANER SYSTEM
SymptomSuspect AreaSee page
ºHeadlight Cleaner Systemº does not operate
(All)
1. H±LP CLN Fuse
2. WASHER Fuse
3. Ignition Switch
4. Headlight Cleaner Switch
5. Headlight Cleaner Relay
6. Headlight Cleaner Motor
7. Headlight Cleaner Nozzle and Hose
8. Wire HarnessBE±21
BE±21
BE±31
BE±73
BE±73
±
±
±
Washer fluid does not spray.Headlight Cleaner Nozzle and Hose±
WIPER AND WASHER SYSTEM
SymptomSuspect AreaSee page
Wipers and washer do not operate.
1. WIP Fuse
2. Wiper Switch
3. Wiper Motor
4. Wire HarnessBE±21
BE±77
BE±77
±
Wipers do not operate in LO, HI or MIST.
1. Wiper Switch
2. Wiper Motor
3. Wire HarnessBE±77
BE±77
±
Wipers do not operate in INT.
1. Wiper Switch
2. Wiper Motor
3. Wire HarnessBE±77
BE±77
±
Washer motor does not operate.
1. WASHER Fuse
2. Washer Switch
3. Washer Motor
4. Wire HarnessBE±21
BE±77
BE±77
±
Wipers do not operate when washer switch ON.
1. WASHER Fuse
2. Washer Switch
3. Wiper Motor
4. Wire HarnessBE±21
BE±77
BE±77
±

± BODY ELECTRICALTROUBLESHOOTING
BE±9
2310 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) Washer fluid does not operate.
Washer Hose and Nozzle±

When wiper switch is in HI position, the wiper blade is in contact
with the body.

When the wiper switch is OFF, the wiper blade does not retract
or the retract position is wrong.
1. Wiper Motor *1
2. Wire harness *1BE±77
±
*1: Inspect wiper arm and blade set positions.
COMBINATION METER
This system uses the multiplex communication system, so check diagnosis system of the multiplex
communication system before you proceed with troubleshooting.
Refer to DI section for warning light or indicator light not described in the table below.
SymptomSuspect AreaSee page
Driver seat belt warning light does not light up.
1. Bulb
2. Driver Buckle Switch CIrcuit
3. Meter Circuit Plate
4. Wire Harness
5. Body No.2 ECU±
BE±92
BE±92
±
DI±820
Passenger seat belt warning light does not light up.
1. Clock System
2. Passenger Buckle Switch CIrcuit
3. Occupant Detection Sensor
4. Meter Circuit Plate
5. Wire Harness
6. Body No.1 ECUBE±227
BE±92
BE±92
BE±92
±
DI±776
SRS warning light does not light up.
1. MPX±B Fuse
2. SRS±B Fuse
3. Bulb
4. Meter Circuit Plate
5. Wire Harness
6. Airbag Sensor AssemblyBE±21
BE±21
±
BE±92
±
DI±550
Hi±beam indicator light does not light up.
1. Bulb
2. Meter Circuit Plate
3. Wire Harness
4. Headlight System±
BE±92
±
BE±3
Turn indicator light does not light up.
1. Bulb
2. Meter Circuit Plate
3. Wire Harness
4. Turn Signal and Hazard Warning System±
BE±92
±
BE±3
ABS warning light does not light up.
1. GAUGE Fuse
2. Bulb
3. Meter Circuit Plate
4. Wire Harness
5. ABS, TRAC and VSC ECUBE±21
±
BE±92
±
DI±387
TRAC warning light does not light up.
1. GAUGE Fuse
2. Bulb
3. Meter Circuit Plate
4. Wire Harness
5. ABS, TRAC and VSC ECUBE±21
±
BE±92
±
DI±473