relay LEXUS GS400 2000 Service Service Manual

I04038
I04039
BE±42
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
2343 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)8 ± Ground
Headlight dimmer switch HIGH beam or FLASHContinuity
1 ± GroundIgnition switch LOCK or ACCNo voltage
1 ± GroundIgnition switch ON or STARTBattery positive voltage
5 ± GroundEngine StopNo voltage
5 ± GroundEngine RunningBattery positive voltage
7 ± GroundConstantBattery positive voltage
9 ± GroundConstantBattery positive voltage
If circuit is specified, try replacing the relay with a new one.
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
16. INSPECT AUTOMATIC LIGHT CONTROL
AUTO ON:
(a) Turn the ignition switch ON.
(b) Turn the light control switch to AUTO.
(c) Gradually cover the top of the sensor.
(d) Check the accessory lights and the headlights should turn
ON.
17. INSPECT AUTOMATIC LIGHT CONTROL
AUTO OFF:
(a) Gradually expose the sensor.
(b) Check the headlights and the accessory lights should turn
OFF.
18. INSPECT LIGHT±OFF CONDITION
(a) Turn the ignition switch ON.
(b) Gradually cover the top of the sensor.
Lights auto ON:
(c) Check that the lights go off under the following conditions.
(1) Light control switch is OFF.
(2) The area surrounding the sensor gets bright.
(3) The driver's door is opened with the ignition switch
OFF.

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.

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)

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.

BE023±07
I01357
Headlight Cleaner Relay Washer Tank

Headlight Cleaner Motor
Headlight Cleaner Switch
Headlight Cleaner Nozzle
Engine Room No.1
Junction Block

H±LP CLN H±Fuse
Ignition Switch
Driver Side Junction Block

WASHER Fuse
BE±72
± BODY ELECTRICALHEADLIGHT CLEANER SYSTEM
2373 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HEADLIGHT CLEANER 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.

BE0HM±03
I04065
I01290
12
34 5 6 Wire Harness Side
e±6±1
I01687
1 2 3
4
5
± BODY ELECTRICALHEADLIGHT CLEANER SYSTEM
BE±73
2374 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT HEADLIGHT CLEANER SWITCH CONTINU-
ITY
Switch positionTester connectionSpecified condition
OFF±No continuity
ON2 ± 4Continuity
Illumination circuit5 ± 6Continuity
If continuity is not as specified, replace the switch.
2. INSPECT HEADLIGHT CLEANER SWITCH CIRCUIT
Disconnect the switch connector and inspect the connector on
wire harness side, as shown.
Tester connectionConditionSpecified condition
1 ± GroundHeadlight ONContinuity
1 ± GroundHeadlight OFFNo continuity
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
3. INSPECT HEADLIGHT CLEANER RELAY OPERATION
(a) Check that no continuity exists between terminals 2 and
5.
(b) Connect the positive (+) lead from the battery to terminals
1 and 5, and the negative (±) lead to terminal 3.
(c) Connect the negative (±) lead from the battery to terminal
4, and check that continuity exists between terminals 2
and 5 for 0.9 ± 1.1 seconds, then no continuity exists.
If operation is not as specified, replace the motor.

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.

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)

I04097
Battery Ignition
SwitchWarning Light
Wire Harness Side
I04098
Wire Harness Side
I04099
BatteryIgnition
SwitchWarning Light
Wire Harness Side BE±100
± BODY ELECTRICALCOMBINATION METER
2401 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
23. INSPECT REAR LIGHTS WARNING LIGHT
(See page DI±841)
(a) Disconnect the connector from the light failure sensor and
ground terminal 3 on the wire harness side connector.
(b) Start the engine, check that the warning light lights up.
If the warning light does not light up, inspect the bulb or wire har-
ness.
24. INSPECT LIGHT FAILURE SENSOR CIRCUIT
Disconnect connector from the light failure sensor and inspect
the connectors on the wire harness side as follows.
Tester connectionConditionSpecified condition
1 ± GroundConstantContinuity *
2 ± GroundConstantContinuity *
6 ± GroundConstantContinuity *
7 ± GroundConstantContinuity *
11 ± GroundConstantContinuity
12 ± GroundConstantContinuity *
5 ± GroundLight control switch OFFNo voltage
5 ± GroundLight control switch in TAIL or HEADBattery positive voltage
8 ± GroundIgnition switch in LOCK or ACCNo voltage
8 ± GroundIgnition switch ONBattery positive voltage
9, 10 ± GroundStop light switch OFFNo voltage
9, 10 ± GroundStop light switch ONBattery positive voltage
*: There is resistance because this circuit is grounded through
the bulb.
If circuit is as specified, replace the relay.
If circuit is not as specified, wiring diagram and inspect the cir-
cuits connected to other parts.
25. INSPECT ENGINE OIL LEVEL WARNING LIGHT
(a) Disconnect the connector from the switch.
(b) Run the engine.
(c) Turn the ignition switch ON, check that the warning light
lights up approximatery 40 seconds later.
If the warning light does not light up, inspect bulb or wire har-
ness.

B01900
CO0AD±03
B00922
ECT
Switch
Connector
B02072
B02073
Ammeter
Battery(+)
(±)
CO±24
± COOLING (2JZ±GE)ELECTRIC COOLING FAN
1562 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
ELECTRIC COOLING FAN
ON±VEHICLE INSPECTION
1. CHECK COOLING FAN OPERATION WITH LOW
TEMPERATURE (Below 83°C (181°F))
(a) Turn the ignition switch ON.
(b) Check that the cooling fan stops.
If not, check the cooling fan relay and ECT switch, and check
for a separated connector or severed wire between the cooling
fan relay and ECT switch.
(c) Disconnect the ECT switch connector.
(d) Check that the cooling fan rotates.
If not, check the fuses, radiator fan main relay, cooling fan relay,
cooling fan, and check for a short circuit between the cooling
fan relay and ECT switch.
(e) Reconnect the ECT switch connector.
2. CHECK COOLING FAN OPERATION WITH HIGH
TEMPERATURE (Above 93°C (199°F))
(a) Start the engine, and raise coolant temperature to above
93°C (199°F).
HINT:
Coolant temperature is the detected value by the ECT switch
on the radiator lower tank.
(b) Check that the cooling fan rotates.
If not, replace the ECT switch.
3. INSPECT COOLING FANS
(a) Disconnect the cooling fan connector.
(b) Connect battery and ammeter to the cooling fan connec-
tor.
(c) Check that the cooling fan rotates smoothly, and check
the reading on the ammeter.
Standard amperage: 8.5 ± 11.5 A at 20°C (68°F)
(d) Reconnect the cooling fan connector.