sensor LEXUS GS400 2000 Service Owner's Guide

I04174
2
18
10
11
I04175
2
18
10
11
I04176
SW1
SW2
SET Switch
I07732
When folded front
At drive
position
At retract position(a)
(b)
(c)
(d)
(e)
± BODY ELECTRICALPOWER MIRROR CONTROL SYSTEM
BE±179
2480 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(e) Disconnect the 4 leads of the battery and voltmeter.
(f) Connect the positive (+) lead from the voltmeter to termi-
nal 10 and negative (±) lead to terminal 11.
(g) Apply battery positive voltage to terminals 1 and 2, then
inspect that the voltage gradually changes according to
the table below while the mirror moves between the left±
most position and right±most position.
Mirror
positionLeft±mostMirror
positionRight±most
Voltage
LEFT2.8 ± 5.0Changes
gradually0 ± 1.8
Voltage
RIGHT0 ± 1.8Changes
gradually2.8 ±5.0
If voltage value is not as specified, replace the motor assembly.
11. w/ Driving position memory only:
INSPECT MIRROR POSITION SENSORS CIRCUIT
Left side: (See page DI±884)
Right side (See page DI±918)
12. INSPECT DRIVING POSITION MEMORY AND RE-
TURN SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
SET switch ON1 ± 7Continuity
Return SW1 ON1 ± 3Continuity
Return SW2 ON1 ± 5Continuity
If continuity is not as specified, replace the switch.
13. INSPECT DRIVING POSITION MEMORY AND RE-
TURN SWITCH CIRCUIT (See page DI±887)
14. TAIWAN models:
INSPECT ELECTRICAL RETRACT MOTOR OPERA-
TION
(a) When folded front position:
(1) Connect the positive (+) lead from the battery to ter-
minal 1 and negative (±) lead to terminal 2, check
that the mirror operates at retract position.
(2) Reverse the polarity, check that the mirror does not
operate.
If operation is not as specified, replace the mirror assembly.
(b) Between folded front position and driving position:
(1) Connect the positive (+) lead from the battery to ter-
minal 1 and negative (±) lead to terminal 2, check
that the mirror operates at retract position.
(2) Reverse the polarity, check that the mirror operate
at folded front position.
If operation is not as specified, replace the mirror assembly.

BE0HD±04
I05186
ºBrightº ºDarkº1
2
3
4
Black coloured tape
I04048
Wire Harnes Side BE±182
± BODY ELECTRICALELECTRO CHROMIC MIRROR SYSTEM
2483 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT ELECTRO CHROMIC INNER MIRROR OP-
ERATION
(a) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 4.
(b) Connect the positive (+) lead from the voltmeter to termi-
nal 2 and the negative (±) lead to terminal 3.
(c) Attach a black coloured tape to forward sensor to prevent
it from sensing.
(d) When the mode is turned to AUTO, check that indicator
light lights up.
(e) Light up the mirror with an electric light, and check that
there is battery positive voltage and mirror surface
changes ºbrightº to ºdarkº.
If operation is not as specified, replace the inner mirror.
2. INSPECT ELECTRO CHROMIC INNER MIRROR CIR-
CUIT
Disconnect the connector from the mirror and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
4 ± GroundConstantContinuity
1 ± GroundIgnition switch LOCK or ACCNo voltage
1 ± GroundIgnition switch ONBattery positive voltage
If circuit is not as specified, inspect the circuits connected to
other parts.

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±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±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

BE±10
± BODY ELECTRICALTROUBLESHOOTING
2311 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) Malfunction indicator light does not light up.
1. Bulb
2. Meter Circuit Plate
3. Wire Harness
4. ECM (2JZ±GE)
5. ECM (1UZ±FE)±
BE±92
±
DI±1
DI±156
Fuel level warning light does not light up.
1. Bulb
2. Fuel level warning sensor
3. Meter Circuit Plate
4. Wire Harness±
±
BE±92
±
ELECTRIC TENSION REDUCER SYSTEM
SymptomSuspect AreaSee page
Tension Reducer does not operate.
(Driver's and Passenger's)1. ECU±IG Fuse
2. Wire HarnessBE±21
±
Tension Reducer does not operate.
(Only one side)1. Buckle Switch
2. Tension Reducer Solenoid
3. Wire HarnessBE±92
BE±92
±
DEFOGGER 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
Rear window defogger does not operate.
1. HTR Fuse
2. DEF M±Fuse
3. Defogger Relay Circuit
4. Defogger Switch (in A/C Panel Switch)
5. Defogger Wire
6. Wire Harness
7. Body No.1 ECUBE±21
BE±21
DI±812
BE±108
BE±108
±
DI±776
Mirror defogger does not operate.
1. MIR±HTR Fuse (Passenger SIde J/B)
2. Mirror Heater Relay
3. Mirror Heater
4. Wire HarnessBE±21
BE±108
BE±108
±
POWER WINDOW CONTROL 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 power windows do not operate.
(Power Door Lock System is normal.)
1. PWS terminal circuit
2. Power Window Master Switch
3. Wire Harness
4. Driver Door ECU
5. Body No.1 ECUDI±818
BE±117
±
DI±856
DI±776
Only the driver's window does not operate.
1. Power Window Master Switch
2. Power WIndow Switch
3. Power Window Motor
4. Wire HarnessBE±117
BE±117
BE±117
±
ºWindow lock functionº does not operate.1. Power Window Master SwitchBE±117
Window does not operate with power window master switch.
(Manual or Automatic operation can be performed.)TROUBLESHOOTING NO.1BE±111
Remote control of all windows (Except driver's) does not functions
with master switch.
(Windows operate normally with each of master switch.)
TROUBLESHOOTING NO.2BE±111

± BODY ELECTRICALTROUBLESHOOTING
BE±13
2314 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
POWER SEAT CONTROL SYSTEM
SymptomSuspect AreaSee page
Both Driver and Passenger Power seats do not operate.
(Door lock does not operate.)1. ALT M±Fuse
2. Wire HarnessBE±21
±
Driver's seat does not operate.
1. P/SEAT (D) Fuse
2. Power Seat Switch (D)
3. Wire HarnessBE±21
BE±167
±
Passenger's seat does not operate.
1. P/SEAT (P) Fuse
2. Power Seat Switch (P)
3. Wire HarnessBE±21
BE±167
±
ºSlide operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Slide Motor (D, P)BE±167
±
BE±167
ºFront Vertical Operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Front Vertical Motor (D, P)BE±167
±
BE±167
ºLifter Operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Lifter Motor (D, P)BE±167
±
BE±167
ºReclining Operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Reclining Motor (D, P)BE±167
±
BE±167
ºLumbar Support Operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Lumbar Support Motor (D, P)BE±167
±
BE±167
(D): Driver's Seat
(P): Passenger's Seat
POWER MIRROR CONTROL SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
w/ Driving Position Memory System:
SymptomSuspect AreaSee page
Both right and left mirrors do not operate.
1. Mirror Switch
2. Wire Harness
3. Body No.2 ECUBE±176
±
DI±820
Only one side of mirror does not operate.
1. Mirror Motor
2. Wire Harness
3. Driver and Passenger Door ECUBE±176
±
DI±856
DI±889
The mirror does not return to the memorized position.
1. Mirror Position Sensor
(Position is not set)
2. Wire Harness
3. Power Seat Control ECU
BE±176
±
DI±683
The memorized position is moved.
1. Mirror Position Sensor
(Position is not set)
2. Wire Harness
BE±176
±

BE0H8±04
I10257
Driver Side Junction Block

GAUGE Fuse

TAIL Fuse

Taillight Control Relay

Body ECU No.2
Combination Switch

Light Control Switch

Headlight Dimmer SwitchIgnition Switch
Daytime Running
Light Main Relay
(w/ D.R.L. System) HeadlightsEngine Room No.1 Junction Block

H±LP L LWR Fuse

H±LP R LWR Fuse

H±LP L UPR Fuse (w/o D.R.L System)

H±LP R UPR Fuse (w/o D.R.L System)

Headight Control Relay D.R.L.: Daytime Running Light
Automatic Light Control Sensor
Headlights
Taillights
Engine Room No.2 Junction Block

Headight Dimmer (D.R.L. No.2) Relay

H±LP R UPR Fuse (w/ D.R.L System)

H±LP L UPR Fuse (w/ D.R.L System)
Light Control ECU Light Control ECU
Daytime Running Light No.3 and No.4 Relay
(w/ D.R.L. System)
Daytime Running Light Resister
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
BE±33
2334 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HEADLIGHT AND TAILLIGHT 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.

BE0H9±05
I04239
Switch BodyWiper and Washer Switch
Light Control Switch and
Headlight Dimmer Switch
Steering Angle Sensor
Steering Position DiscSpiral Cable
Tilt and Telescopic Switch
Compression Spring
Cancel Cam
BE±34
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
2335 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMPONENTS

I04240
BE0K2±02
I04241
I04242
I04243
I04244
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
BE±35
2336 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. REMOVE SPIRAL CABLE
Remove the 4 screws and the spiral cable.
2. REMOVE WIPER AND WASHER SWITCH
Remove the 2 screws and the wiiper and washer switch.
3. REMOVE TILT AND TELESCOPIC SWITCH
Remove a screw and the tilt and telescopic switch.
4. REMOVE STEERING ANGLE SENSOR
Disengage the 2 claws and the steering angle sensor.
5. REMOVE LIGHT CONTROL SWITCH
Remove the 2 screws and the light control switch.