ignition LEXUS GS400 2000 Service Manual PDF

I05442
I05441
13 m sec./ DivisionMotor operating 5V
/ Division
GND Pulse generation
± BODY ELECTRICALHEADLIGHT BEAM LEVEL CONTROL SYSTEM
BE±51
2352 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU
CIRCUIT
Connector connected:
Connect the connector from the ECU and inspect the connec-
tor, as shown in the table.
Tester connectionConditionSpecified condition
A1 ± A4Ignition switch ONBattery positive voltage
A1 ± A5Ignition switch ON, when stopping and bouncing
the vehicle.Pulse generation
A1 ± A6Ignition switch ON, when stopping and bouncing
the vehicle.Pulse generation
A1 ± A7Ignition switch ON, when stopping and bouncing
the vehicle.Pulse generation
A1 ± A8Ignition switch ON, when stopping and bouncing
the vehicle.Pulse generation
B2 ± B3Ignition switch ONApprox. 2.5 V
B6 ± B7Ignition switch ONApprox. 2.5 V
B1 ± B3
B5 ± B7Ignition switch ON5 V
If the circuit is not as specified, replace the ECU.
Reference INSPECTION USING OSCILLOSCOPE
HINT:
The correct waveform is as shown in the illustration.

BE0H0±06
I01353
Turn Signal LightsEngine Room No.1
Junction Block

TURN HAZ Fuse
Ignition Switch
Combination Switch

Turn Signal Switch
Hazard Warning Switch
Turn Signal Lights Turn Signal Lights
Driver Side Junction Block

GAUGE FuseCowl Side No.5
Junction Block

Turn Signal Flaher
± BODY ELECTRICALTURN SIGNAL AND HAZARD WARNING SYSTEM
BE±55
2356 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
TURN SIGNAL AND HAZARD WARNING 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
1 2 3
I04044
I04045
Wire Harness Side
± BODY ELECTRICALTURN SIGNAL AND HAZARD WARNING SYSTEM
BE±57
2358 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT TURN SIGNAL SWITCH CIRCUIT
Connector connected:
Connect the wire harness side connector to the combination
switch and inspect the connector form the back side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundIgnition switch ON and turn signal switch NeutralNo voltage
1 ± GroundIgnition switch ON and turn signal switch LeftBattery positive voltage e 0 V
3 ± GroundIgnition switch ON and turn signal switch RightBattery positive voltage e 0 V
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
4. INSPECT HAZARD WARNING SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
Switch OFF7 ± 10Continuity
Switch ON7 ± 8Continuity
Illumination circuit2 ± 3Continuity
If continuity is not as specified, replace the switch.
5. INSPECT HAZARD WARNING SWITCH CIRCUIT
(See page DI±814)
Disconnect the switch connector and inspect the connection on
the wire harness side, as shown.
Tester connectionConditionSpecified condition
8 ± GroundConstantContinuity
If circuit is not as specified, inspect the circuits connected to oth-
er parts.

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.

BE0GW±08
I01355
Ignition Switch
Driver Side Junction Block

GAUGE Fuse
Back±up Lights
Park/Neutral Position Switch
± BODY ELECTRICALBACK±UP LIGHT SYSTEM
BE±67
2368 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
BACK±UP LIGHT SYSTEM
LOCATION

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.

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.

BE0HN±07
I01358
Wiper Motor
Washer Tank

Washer Motor
Combination Switch

Wiper and Washer Switch
Driver Side Junction Block

WIPER Fuse

WASHER Fuse
Ignition Switch
BE±76
± BODY ELECTRICALWIPER AND WASHER SYSTEM
2377 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
WIPER AND WASHER 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.

BE0HO±04
I04070
OFF
INT
LO
HIWasher ON
I04034
Wire Harness Side
2
17
I04071
54
± BODY ELECTRICALWIPER AND WASHER SYSTEM
BE±77
2378 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT WIPER AND WASHER SWITCH CONTINU-
ITY
Switch positionTester connectionSpecified condition
OFF7 ± 16Continuity
INT7 ± 16Continuity
LO7 ± 17Continuity
HI8 ± 17Continuity
Washer OFF±No continuity
Washer ON2 ± 11Continuity
If continuity is not as specified, replace the switch.
2. INSPECT WIPER AND WASHER SWITCH 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 ± GroundConstantContinuity
17 ± GroundIgnition switch LOCK or ACCNo voltage
17 ± GroundIgnition switch ONBattery positive voltage
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
3. INSPECT WIPER MOTOR OPERATION
Low speed:
Connect the positive (+) lead from the battery to terminal 5 and
the negative (±) lead to terminal 4, check that the motor oper-
ates at low speed.
If operation is not as specified, replace the motor.

I04072
4 3
I04073
54
I04074
1
54 2
I04076
Wire Harness Side BE±78
± BODY ELECTRICALWIPER AND WASHER SYSTEM
2379 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. INSPECT WIPER MOTOR OPERATION
High speed:
Connect the positive (+) lead from the battery to terminal 3 and
the negative (±) lead to terminal 4, check that the motor oper-
ates at high speed.
If operation is not as specified, replace the motor.
5. INSPECT WIPER MOTOR OPERATION
Stopping at stop position:
(a) Operate the motor at low speed and stop the motor opera-
tion anywhere except at the stop position by disconnect-
ing positive (+) lead from terminal 5.
(b) Connect terminals 1 and 5.
(c) Connect the positive (+) lead from the battery to terminal
2 and negative (±) lead to terminal 4, check that the motor
stops running at the stop position after the motor operates
again.
If operation is not as specified, replace the motor.
6. INSPECT WIPER 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
4 ± GroundConstantContinuity
2 ± GroundIgnition switch LOCK or ACCNo voltage
2 ± GroundIgnition switch ONBattery positive voltage
If circuit is not as specified, inspect the circuits connected to oth-
er parts.