fog light LEXUS GS400 2000 Service Repair Manual

BE0GT±03
I04112
6
I04113
I04114
Wire Harness Side
Connector ºAº Connector ºBº
I01200
2 1
35
2 5
1 3
BE±108
± BODY ELECTRICALDEFOGGER SYSTEM
2409 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT DEFOGGER TIMER OPERATION
(a) Connect the positive (+) lead from the voltmeter to termi-
nal 6 of body ECU No.1 connector and negative (±) lead
to body ground.
(b) When the switch is OFF, the voltage should be approx.
12V.
(c) Turn the defogger switch ON and check that the indicator
lights up and that the voltage is less than 1 V.
(d) After 15 minutes, check that the switch is OFF and the
voltage is approx. 12 V.
If operation is not as specified, replace the switch.
2. INSPECT DEFOGGER SWITCH (in PANEL SWITCH)
CIRCUIT
Connector disconnected:
Disconnect the connector from the panel switch and inspect the
connector on wire harness side, as shown in the chart.
Tester connectionConditionSpecified condition
B10 ± GroundConstantContinuity
A1 ± GroundConstantBattery voltage
A2 ± GroundIgnition switch LOCKNo voltage
A2 ± GroundIgnition switch ACC or ONBattery voltage
If the circuit is not as specified, replace the switch.
3. INSPECT DEFOGGER RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
4. INSPECT DEFOGGER RELAY CIRCUIT
(See page DI±812 and BE±21)

I04029
Fuses
Relays 1. AM1 H±Fuse
2. WASHER Fuse
3. FOG Fuse
4. TAIL Fuse
B. Taillight Control Relay A. Fog Light Relay
C. Body ECU No.2
Driver Side Instrument Panel Junction Block
5. SRS±ACC Fuse
6. GAUGE Fuse
7. FUEL OPN Fuse
8. D FR DOOR Fuse
9. PANEL Fuse
10. HTR Fuse
11. SRS±B Fuse
12. P/SEAT (D) Fuse
13. RAD NO.2 Fuse
14. WIP Fuse
15. OBD Fuse
16. STOP Fuse
17. CIG Fuse
18. ECU±IG Fuse
19. STARTER Fuse
20. IGN Fuse
21. D FR DOOR Fuse
2
21 34 5
678 9
10 11 12 13
14 15 16 17
18 19 20AB
C 1
± BODY ELECTRICALPOWER SOURCE
BE±19
2320 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

BE±26
± BODY ELECTRICALPOWER SOURCE
2327 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(a) Remove the fuse from the junction block and inspect the
connector on junction block side.
Fuse Tester connectionConditionSpecified condition
AM1 1 ± GroundConstantBattery positive voltage
WASHER 3 ± GroundIgnition switch ONBattery positive voltage
FOG 5 ± GroundConstantBattery positive voltage
TAIL 7 ± GroundLight control switch TAIL or HEADBattery positive voltage
SRS±ACC 9 ± GroundIgnition switch ACC or ONBattery positive voltage
GAUGE 11 ± GroundIgnition switch ONBattery positive voltage
FUEL OPN 13 ± GroundConstantBattery positive voltage
D FR DOOR 15 ± GroundConstantBattery positive voltage
PANEL 17 ± GroundLight control switch TAIL or HEADBattery positive voltage
HTR 19 ± GroundIgnition switch ONBattery positive voltage
SRS±B 21 ± GroundConstantBattery positive voltage
P/SEAT (D) 23 ± GroundConstantBattery positive voltage
RAD NO.2 25 ± GroundIgnition switch ACC or ONBattery positive voltage
WIP 27 ± GroundIgnition switch ONBattery positive voltage
OBD 29 ± GroundConstantBattery positive voltage
STOP 31 ± GroundConstantBattery positive voltage
CIG 33 ± GroundIgnition switch ACC or ONBattery positive voltage
ECU±IG 35 ± GroundIgnition switch ONBattery positive voltage
ST 37 ± GroundIgnition switch ONBattery positive voltage
IGN 39 ± GroundIgnition switch ONBattery positive voltage
D RR DOOR 41 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.
(b) Remove the relay from the junction block and inspect the
connector on junction block side.
Relay Tester connectionConditionSpecified condition
Fog light 43 ± GroundConstantBattery positive voltage
Fog light 44 ± GroundConstantContinuity
Fog light 46 ± GroundLight control switch HEADBattery positive voltage
Taillight 47 ± GroundConstantBattery positive voltage
Taillight 48 ± GroundConstantContinuity
Taillight 50 ± GroundConstantContinuity
If the circuit is not as specified, inspect the circuits connected
to other parts.

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±
±

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

I04035
From Back Side
8 18
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
BE±39
2340 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)Tester connection
ConditionSpecified condition
13 ± GroundLight control switch OFF, TAIL or HEADNo voltage
13 ± GroundLight control switch AUTOBattery positive voltage
14 ± GroundLight control switch OFF or TAILNo voltage
14 ± GroundLight control switch HEADBattery positive voltage
15 ± GroundLight control switch OFFNo voltage
15 ± GroundLight control switch TAIL or HEADBattery positive voltage
If circuit is not as specified, inspect the wire harness.
7. INSPECT HEADLIGHT DIMMER SWITCH CIRCUIT
Connector connected:
Connect the wire harness side connector to the light control and
dimmer switch and inspect the connector from the back side, as
shown.
Tester connectionConditionSpecified condition
8 ± Ground
Headlight dimmer switch FLASH
Light control switch HEAD and dimmer switch
HIGH
No voltage
8 ± GroundLight control switch HEAD and
dimmer switch LOWBattery positive voltage
18 ± GroundLight control switch HEAD and
dimmer switch LOW and fog light switch ONNo voltage
18 ± Ground
Light control switch HEAD and
dimmer switch HIGH or FLASH and fog light
switch ON
Battery positive voltage
If circuit is not as specified, inspect the wire harness.

BE0H2±08
I01352
Front Fog Lights
Combination Switch

Front Fog Light Switch Driver Side Junction Block

FOG Fuse

Fog Light Relay

Body ECU No.2
BE±52
± BODY ELECTRICALFOG LIGHT SYSTEM
2353 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
FOG LIGHT 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.

I04040
ON
OFF
BE0H3±02
I04034
Wire Harness Side
11
± BODY ELECTRICALFOG LIGHT SYSTEM
BE±53
2354 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT FOG LIGHT SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
OFF±No continuity
ON11 ± 12Continuity
If continuity is not as specified, replace the switch.
2. INSPECT FOG LIGHT SWITCH CIRCUIT
Connector disconnected:
(See page DI±832)
Disconnect the connector from the switch and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
11 ± GroundLight control switch TAIL or HEAD and dimmer
switch LOW or HIContinuity
If circuit is not as specified, inspect the wire harness.

I04035
From Back Side
11
I01200
2 1
35
2 5
1 3
BE±54
± BODY ELECTRICALFOG LIGHT SYSTEM
2355 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT FOG LIGHT SWITCH CIRCUIT
Connector connected:
Connect the wire harness side connector to the light control and
dimmer switch and inspect the connector from the back side, as
shown.
Tester connectionConditionSpecified condition
11 ± GroundLight control switch HEAD and headlight dimmer
switch LO and fog light switch ONNo voltage
11 ± GroundLight control switch HEAD and headlight dimmer
switch HI or FLASH and fog light switch ONBattery positive voltage
If circuit is not as specified, inspect the wire harness.
4. INSPECT FOG LIGHT RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
5. INSPECT FOG LIGHT RELAY CIRCUIT
(See page BE±21)

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)