2000 LEXUS GS400 Service Repair Manual

I04297
Beam Angle Gauge
(Vertical Alignment)
Acceptable
Range
Bubble
I04298
º0º Mark
(Horizontal Alignment)A
B
Lens BE±46
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
2347 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
1. ADJUST HEADLIGHT AIMMIMG
(a) Inspect the headslight aimming.
Do the following items before inspection.

Make sure the body around the headlight is
not deformed.

Park the vehicle on a level spot.

The driver gets into the driver's seat and puts
the vehicle in a state ready for driving (with a
full tank).

Bounce the vehicle several times.
(b) Adjust the headlight aimming.

Vertical Alignment:
If the bubble is out of the acceptable range of the
beam angle gauge, adjust it using bolt A.

Horizontal Alignment:
If the edge of the lens does not match º0º mark, ad-
just the lens using bolt B.
HINT:
After adjusting the headlight in vertical direction, check that the
light has been shifted from the adjusted position in the horizon-
tal direction.
2. REPLACE HEADLIGHT
(a) Replace the headlight.
(b) Inspect the headlight aimming.
Do the following items before inspection.

Make sure the body around the headlight is
not deformed.

Park the vehicle on a level spot.

The driver gets into the driver's seat and puts
the vehicle in a state ready for driving (with a
full tank).

Bounce the vehicle several times.

I07728
20.9 mm (0.823 in.)
0.4°
3 m (9.84 ft)
W
V Center
Line
V LH Line V RH Line
H
HRH Line3 cm
(0.57°)LH
Line
W
I04297
Beam Angle Gauge
(Vertical Alignment)
Acceptable
Range
Bubble
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
BE±47
2348 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(c) Check the headlight aimming.
(1) Prepare the thick white colored paper.
(2) Stand the paper perpendicularly and ensure the
distance from it to the head lights is 9.84 ft.
(3) Ensure that the center line of vehicle and the paper
are at a 90 degree angle as shown in the illustration.
(H line)
(4) Engine running.
(5) Draw a horizontal line on the paper where the head
lights of the vehicle are to be.
(6) Draw a vertical line on the paper where the center
line of the vehicle is to be. (V center line)
(7) Take an appropriate measure to avoid affecting the
other light. (V RH and LH lines)
NOTICE:

Disconnect the connector of the other light to avoid
heat affection from the light because the outer lens of
the head light assembly is made of synthetic resin.
When connecting the connector again take care not
to wake the aiming out of adjustment.

When covering the headlight, finish it within 3 min-
utes.
(8) Turn the head lights ON.
(9) Check that the head lights light up the paper as
shown in the illustration.
(10) When the paper is not lighted up properly, adjust the
lights in the vertical or horizontal direction.
HINT:
As shown in the illustration, adjust aiming of the LH and RH
lights along each vertical line respectively.
(d) Vertical Alignment:
Adjust the headlight aimming.
(1) Using adjustment bolt A, adjust the headlight aim-
ing to within the specifiactions.
(2) Make sure the gauge bubble is within the accept-
able range.
HINT:
If the gauge bubble is outside the acceptable range, check that
the vehicle is parked on a level spot.
Readjust the headlight aiming after parking the vehicle on a lev-
el spot.

I04298
º0º Mark
(Horizontal Alignment)A
B
Lens BE±48
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
2349 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(e) Horizontal Alignment:
Adjust the headlight aimming.
If the edge of the lens does not match the paper as shown
in the illustration, adjust the lens using bolt B. (See step
5)
HINT:
After adjusting the headlight in vertical direction, check that the
light has been shifted from the adjusted position in the horizon-
tal direction.

BE01R±06
I01351
Headlight Beam Level Control Actuator
Height Control SensorHeadlight Beam Level Control ECU
Driver Side Junction Block

ECU±IG Fuse

GAUGE Fuse
± BODY ELECTRICALHEADLIGHT BEAM LEVEL CONTROL SYSTEM
BE±49
2350 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HEADLIGHT BEAM LEVEL CONTROL 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.

BE0HP±02
I03440
1 2 3
4 5 6
I05442
Wire Harness Side BE±50
± BODY ELECTRICALHEADLIGHT BEAM LEVEL CONTROL SYSTEM
2351 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT HEADLIGHT BEAM LEVEL CONTROL AC-
TUATOR RESISTANCE
(a) Check that continuity exists between terminals 2 and 5.
(b) Check that resistance exists between terminals, as
shown in the chart.
TerminalResistance (W)
2 ± 126 ± 30
2 ± 326 ± 30
2 ± 426 ± 30
2 ± 626 ± 30
5 ± 126 ± 30
5 ± 326 ± 30
5 ± 426 ± 30
5 ± 626 ± 30
If resistance value is not as specified, replace the actuator.
2. INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU
CIRCUIT
Connector disconnected:
Disconnect the connector from the ECU and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
A1 ± A5Ignition switch OFF26 ± 30 W
A1 ± A6Ignition switch OFF26 ± 30 W
A1 ± A7Ignition switch OFF26 ± 30 W
A1 ± A8Ignition switch OFF26 ± 30 W
A4 ± B4Ignition switch ON and light control switch HEADBelow 1.5 V
B1 ± B3Ignition switch OFF3.5 ± 6.5 kW
B5 ± B7Ignition switch OFF3.5 ± 6.5 kW
A4 ± GroundIgnition switch OFFContinuity
If circuit is not as specified, perform the inspection on the follow-
ing pages.

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.

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.