lights LEXUS GS400 2000 Service User Guide

BE0G7±07
START
Insert the key in the key cylinder.
Under registration
Registration completion
Remove the key.
Will you register the
next key?
NoSecurity indicator blinks until the first
key is inserted. The indicator light
lights up after the key registration.
Security Indicator ON
Security Indicator
OFF
END Ye s
Security Indicator ON
(After the last key (sub±key)
has been registered, the indi-
cator goes off.)
BE±238
± BODY ELECTRICALENGINE IMMOBILISER SYSTEM
2539 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
ENGINE IMMOBILISER SYSTEM
REGISTRATION PROCEDURE
1. KEY REGISTRATION IN AUTOMATIC REGISTRATION MODE
(a) Registration of a new transponder key.
HINT:

This must be done when you install a new ECM.

The new ECM is in the automatic key code registration mode. The already fixed number of key codes
for this ECM can be registered.
On this type of vehicle, up to 3 key codes can be registered.

In the automatic registration mode, the key registered last becomes the sub±key.

1.2 Sec.
0.8 Sec.
0.25 Sec. 0.5 Sec.0.25 Sec.
1 Sec. Blinks
Code 2±1 Code2±2
0.25 Sec.
0.25 Sec.0.5 Sec. 1 Sec.
± BODY ELECTRICALENGINE IMMOBILISER SYSTEM
BE±239
2540 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HINT:

When a key is not inserted in the key cylinder in the automatic registration mode, the security indicator
always lights on.

When the immobiliser system operates normally and the key is pulled out, the security indicator blinks.

When key code registration could not be performed in the automatic registration mode, code 2±1 is
output from the security indicator and when inserting the already registered key, code 2±2 is output.
(b) Automatic registration mode completion
If completing the mode forcibly when more than 1 key code have been registered in the automatic reg-
istration mode, perform the following procedures.
After 1 more key code have been registered with master key, perform step (1) or (2) without pulling
the key out or inserting the already registered key.
(1) Depress and release brake pedal 5 times or more within 15 sec.
(2) With the LEXUS hand±held tester, require automatic registration mode completion.

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±7
2308 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INTERIOR 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
All the lights do not come ON.1. DOME Fuse
2. Body ECU NO.2BE±21
±
The light does not come ON when the driver's door is opened.1. Driver's Door Courtesy Switch
2. Wire HarnessBE±60
±
The light does not come ON when the passenger's door is
opened.1. Passenger's Door Courtesy Switch
2. Wire HarnessBE±60
±
The light does not come on when the rear±right door is opened.1. Rear±Right Door Courtesy Switch
2. Wire HarnessBE±60
±
The light does not come on when the rear±left door is opened.1. Rear±Left Door Courtesy Switch
2. Wire HarnessBE±60
±
Only one of the bulbs comes ON.Bulb±
The illumination does not fade out when all the doors are closed.1. Courtesy Switch
2. Wire HarnessBE±60
±
The illumination does not fade out immediately when the ignition
switch is turned to ACC or ON within 15 seconds after all the
doors are closed.1. Ignition Switch
2. RADIO NO.2 Fuse
3. GAUGE Fuse
4. Wire HarnessBE±31
BE±21
BE±21
±
The illumination does not fade out immediately when all the doors
are locked within 15 seconds after they are closed.1. Door Unlock Detection Switch
2. Wire HarnessBE±131
±
Interior light does not light up.
(in front personal light)1. Bulb
2. Front Personal Light
3. Wire Harness±
BE±60
±
Front personal light does not light up.
1. Bulb
2. Front Personal Light
3. Wire Harness±
BE±60
±
Rear personal light does not light up.
1. Bulb
2. Rear Personal Light
3. Wire Harness±
BE±60
±
Vanity light does not light up.
1. Bulb
2. Vanity Light
3. Wire Harness±
BE±60
±
Luggage compartment light does not light up.
1. Bulb
2. Luggage Compartment Door Courtesy Switch
3. Wire Harness±
BE±60
±
Courtesy light does not light up.
1. Bulb
2. Door Courtesy Switch
3. Wire Harness±
BE±60
±

BE±8
± BODY ELECTRICALTROUBLESHOOTING
2309 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
BACK±UP LIGHT SYSTEM
SymptomSuspect AreaSee page
Back±Up Light does not light up.
1. GAUGE Fuse
2. Ignition Switch
3. Wire Harness
4. BulbBE±21
BE±31
±
±
Back±Up Light remains always on.1. Park/ Neutral Position Switch
2. Wire HarnessDI±372
±
Only one light does not light up.1. Bulb
2. Wire Harness±
±
STOP LIGHT SYSTEM
SymptomSuspect AreaSee page
Stop light does not light up.
1. STOP Fuse
2. Stop Light Switch
3. Light Failure Relay
4. Wire HarnessBE±21
BE±70
BE±92
±
Stop light always lights up.1. Stop Light Switc
2. Wire HarnessBE±70
±
Only one light always lights up.Wire Harness±
Only one light does not light up.1. Bulb
2. Wire Harness±
±
HEADLIGHT CLEANER SYSTEM
SymptomSuspect AreaSee page
ºHeadlight Cleaner Systemº does not operate
(All)
1. H±LP CLN Fuse
2. WASHER Fuse
3. Ignition Switch
4. Headlight Cleaner Switch
5. Headlight Cleaner Relay
6. Headlight Cleaner Motor
7. Headlight Cleaner Nozzle and Hose
8. Wire HarnessBE±21
BE±21
BE±31
BE±73
BE±73
±
±
±
Washer fluid does not spray.Headlight Cleaner Nozzle and Hose±
WIPER AND WASHER SYSTEM
SymptomSuspect AreaSee page
Wipers and washer do not operate.
1. WIP Fuse
2. Wiper Switch
3. Wiper Motor
4. Wire HarnessBE±21
BE±77
BE±77
±
Wipers do not operate in LO, HI or MIST.
1. Wiper Switch
2. Wiper Motor
3. Wire HarnessBE±77
BE±77
±
Wipers do not operate in INT.
1. Wiper Switch
2. Wiper Motor
3. Wire HarnessBE±77
BE±77
±
Washer motor does not operate.
1. WASHER Fuse
2. Washer Switch
3. Washer Motor
4. Wire HarnessBE±21
BE±77
BE±77
±
Wipers do not operate when washer switch ON.
1. WASHER Fuse
2. Washer Switch
3. Wiper Motor
4. Wire HarnessBE±21
BE±77
BE±77
±

I04265
I01663
1 2 OFF
ON
3 4
I04032
Wire Harness Side BE±32
± BODY ELECTRICALIGNITION SWITCH AND KEY UNLOCK WARNING
SWITCH
2333 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT IGNITION KEY ILLUMINATION OPERATION
Connect the positive (+) lead from the battery to terminal 1 and
the negative (±) lead to terminal 2, and check that the indicator
light lights up.
If operation is not as specified, replace the switch.
4. INSPECT IGNITION KEY ILLUMINATION CIRCUIT
(See page DI±843)
5. INSPECT KEY UNLOCK WARNING SWITCH CONTI-
NUITY
Switch positionTester connectionSpecified condition
OFF (Key removed)±No continuity
ON (Key set)1 ± 2Continuity
If continuity is not as specified, replace the switch.
6. INSPECT KEY UNLOCK WARNING SWITCH CIRCUIT
(See page DI±828)
Connect the switch connector and inspect the connector on
wire harness side from the back side, as shown.
Tester connectionConditionSpecified condition
1 ± GroundConstantContinuity
If circuit is not as specified, inspect the circuits connected to oth-
er parts.

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.

BE0HA±02
I04033
HI
Flash OFFTAIL HEAD AUTO
LO
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
BE±37
2338 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. FAIL±SAFE FUNCTION
(Light Control ECU)
When input error is inspected.
When input voltage is not within the range of operation voltage (9 to 16 V),
lighting of the headlight stops. As soon as the voltage comes within the range,
it lights up again.
However if the input voltage becomes low after lighting up,
sufficient voltage is maintained until light of bulb completely goes off.
When output error is inspected (Open or short).
When light flushing is inspected.
When an error occurs in the output voltage (open or short) or flushing symptom
occurs on the bulb, lighting of the headlight stops, the condition is maintained
until power is turned ON again (headlight dimmer switch OFF " ON).
In this case, it can not be judged whether lighting malfunction is caused by an
output error or other reasons (fuse blown out, etc.).
Check that there is no error in fuse and wiring (including power source) and
replace the bulb in the first place, when the error still appears, replace the light
control ECU.
2. INSPECT LIGHT CONTROL SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
OFF±No continuity
TAIL15 ± 16Continuity
HEAD14 ± 15 ± 16Continuity
AUTO13 ± 16Continuity
If continuity is not as specified, replace the switch.
3. INSPECT HEADLIGHT DIMMER SWITCH CONTINU-
ITY
Switch positionTester connectionSpecified condition
Low beam17 ± 18Continuity
High beam8 ± 17Continuity
Flash8 ± 9 ± 17Continuity
If continuity is not as specified, replace the switch.

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.

I01254
Wire Harness Side
4 3 2 1
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
BE±43
2344 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
19. INSPECT LIGHTS±ON CONDITION
(a) Open the driver's door while the ignition switch is OFF.
(b) Turn the light control switch to AUTO leaving the door
open and cover the top of the sensor, and verify that the
lights go on when the ignition switch is turned ON.
20. INSPECT AUTOMATIC LIGHT CONTROL SENSOR
CIRCUIT
Connector disconnected:
Disconnect the connector from the sensor and inspect the con-
nector on the wire harness side, as shown in the table.
Tester connectionConditionSpecified condition
3 ± GroundConstantContinuity
1 ± GroundIgnition switch LOCK or ACCNo voltage
1 ± GroundIgnition switch ONBattery positive voltage
4 ± GroundIgnition switch LOCK or ACCNo voltage
4 ± GroundIgnition switch ON5.2 ± 9.0 V
If circuit is as specified, perform the inspection on the following
page.
If the circuit is not as specified, inspect the circuit connected to
other parts.