ignition LEXUS GS400 2000 Service Service Manual

I04188
Wire Harness Side
± BODY ELECTRICALAUDIO SYSTEM
BE±219
2520 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. NAKAMICHI made:
INSPECT CD AUTO CHANGER CIRCUIT
Disconnect connectors from CD auto changer and inspect the
connector on the wire harness side.
Tester connectionConditionSpecified condition
14 ± GroundConstantContinuity
4 ± GroundIgnition switch LOCKNo voltage
4 ± GroundIgnition switch ACC or ONBattery positive voltage
5 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.
HINT:

Check the wire harness between the radio receiver as-
sembly and the CD auto changer.

Since the signals to and from the MUTE, R±, R+, L±, L+,
TX
± and TX+ terminals are serial signals, they cannot or-
dinarily be measured with a tester.

I04309
Wire Harness Side
Connector ºBº
Connector ºDº Connector ºCº Connector ºAº BE±220
± BODY ELECTRICALAUDIO SYSTEM
2521 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. NAKAMICHI made:
INSPECT POWER AMPLIFIER CIRCUIT
Disconnect the connector from power amplifier and inspect the
connector on the wire harness side.
Tester connectionConditionSpecified condition
A1 ± Ground
A4 ± Ground
D1 ± Ground
ConstantContinuity
A6 ± GroundIgnition switch LOCK and radio switch ONNo voltage
A6 ± GroundIgnition switch ACC or ON and radio switch ONBattery positive voltage
A2 ± GroundConstantBattery positive voltage
A5 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.

I04189
Wire Harness Side
Connector ºBº
Connector ºDº Connector ºCº Connector ºAº
± BODY ELECTRICALAUDIO SYSTEM
BE±221
2522 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. NAKAMICHI made:
INSPECT RADIO RECEIVER ASSEMBLY CIRCUIT
Disconnect the connectors from the radio receiver assembly,
and inspect the connector on the wire harness side.
Tester connectionConditionSpecified condition
D3 ± GroundConstantContinuity
D4 ± GroundConstantBattery positive voltage
D1 ± GroundIgnition switch LOCKNo voltage
D1 ± GroundIgnition switch ACC or ONBattery positive voltage
*: w/ LEXUS navigation system
If the circuit is not as specified, inspect the circuits connected
to other parts.
HINT:
Check the wire harness between radio receiver assembly and
the CD auto changer, between radio receiver assembly and
power amplifier.
7. INSPECT GLASS IMPRINTED ANTENNA
(Use same procedure as for ºINSPECT DEFOGGER WIRESº
on page BE±108.)
8. REPAIR GLASS IMPRINTED ANTENNA
(Use same procedure as for ºREPAIR DEFOGGER WIRESº on
page BE±108.)

BE0N6±04
I05587
2 5
I05580
2 5
Z08688
2 13
45 768 Wire Harness Side
± BODY ELECTRICALANTENNA
BE±225
2526 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. Auto Antenna Models:
INSPECT ANTENNA MOTOR
(a) Connect the positive (+) lead from the battery to terminal
2 and the negative (±) lead to terminal 5.
(b) Check that the motor turns (moves upward).
NOTICE:
These tests must be done quickly (within 3 ± 5 seconds) to
prevent the coil from burning out.
(c) Then, reverse the polarity, check that the motor turns the
opposite way (moves downward).
NOTICE:
These tests must be done quickly (within 3 ± 5 seconds) to
prevent the coil from burning out.
2. Auto Antenna Models:
INSPECT ANTENNA MOTOR CONTROL RELAY CIR-
CUIT
Disconnect the connector from the relay and inspect the con-
nector on wire harness side, as shown in the chart below.
Tester connectionConditionSpecified condition
7 ± GroundConstantContinuity
1 ± GroundIgnition switch ACC or ON,
and radio switch ON and OthersNo voltage
1 ± GroundIgnition switch ACC or ON,
and radio switch ON and AMBattery positive voltage
2 ± GroundIgnition switch ACC or ON,
and radio or tape or CD switch OFFNo voltage
2 ± GroundIgnition switch ACC or ON,
and radio or tape or CD switch ONBattery positive voltage
3 ± GroundConstantBattery positive voltage
4 ± GroundIgnition switch ACC or ON,
and radio switch ON and OthersNo voltage
4 ± Ground
Ignition switch ACC or ON,
and radio switch ON and
AM or FM (87.9 ± 96.0 MHz)
Battery positive voltage
5 ± GroundIgnition switch ACC or ON,
and radio switch OFFNo voltage
5 ± GroundIgnition switch ACC or ON,
and radio switch ONBattery positive voltage

BE±226
± BODY ELECTRICALANTENNA
2527 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)6 ± Ground
Ignition switch ACC or LOCKNo voltage
6 ± GroundIgnition switch ONBattery positive voltage
8 ± GroundIgnition switch LOCKNo voltage
8 ± GroundIgnition switch ACC or ONBattery positive voltage
If circuit is as specified, replace the relay.

I04311
I04312
BE±240
± BODY ELECTRICALENGINE IMMOBILISER SYSTEM
2541 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. KEY REGISTRATION PROCEDURE WHEN KEY OR KEY CYLINDER HAS BEEN REPLACED.
HINT:
Key registration procedure of new master key and new sub±key on this vehicle when new ignition cylinder
and key set, and new lock cylinder set including ignition key cylinder are installed is described below.
(a) Removing wire±less and immobiliser module from origi-
nal master key.
(b) Making new master key.
After replacing and installing new ignition cylinder, install
the removed original modules into new 2 key housings as
supply parts.
(c) Registration of supplied new sub±key and /or master key
Register supplied new sub±key and /or master key by us-
ing new master key.
(See step 3 and 4)
NOTICE:
In case of replacing ignition cylinder and key set, door
locks cannot be opened with new ignition keys. Therefore,
to avoid any trouble caused by empty battery of transmitter
of new ignition key, please bring the original key while driv-
ing.

Will you register the
next key?
No Ye s
Insert already registered master key in the key
cylinder
Depress and release the acceleration pedal 5
times.
Depress and release the brake pedal 6 times,
and remove the master key.
Insert key to be registered in key cylinder.
Depress and release the acceleration pedal 1
time. (Security indicator blinks.)
The registration mode completes when pulling
out the key and depressing and releasing the
brake pedal once or more within 10 secs. after
indicator has been OFF or 10 sec. have passed. Within 10 sec.Within 15 sec.
Within 20 sec.
Within 10 sec.
Within 10 sec.
After 60 sec. additional master key is registered.
(Security indicator is OFF.)
± BODY ELECTRICALENGINE IMMOBILISER SYSTEM
BE±241
2542 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(d) There are 2 ways for registration of additional master key, one way is depressing brake pedal and ac-
celeration pedal and the other way is using LEXUS hand±held tester.
HINT:

It is possible to register up to 7 master key codes including the already registered key code.

When any operation time described below is over, registration mode completes.

When the next procedure is performed while the timer is working, the timer completes counting time,
then next timer starts.

When replacing ºIgnition Cylinder Key Setº or ºLock Cylinder Setº register according to the following
procedure using the original master key. However, after the registration of the additional master key,
as the original master key and the original sub±key are not necessary any more, erase registered of
those key codes.
(1) Depressing brake pedal and acceleration pedal:

BE19B±01
± BODY ELECTRICALTROUBLESHOOTING
BE±3
2304 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
TROUBLESHOOTING
PROBLEM SYMPTOMS TABLE
IGNITION SWITCH AND KEY UNLOCK WARNING SWITCH
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
Ignition Switch:
SymptomSuspect AreaSee page
Ignition switch is not set to each position.4. Ignition switch
5. Power source circuitBE±31
±
Key Unlock Warning Switch:
SymptomSuspect AreaSee page
Key unlock warning system does not operate.
(The buzzer does not sound when the driver's door is opened with
the ignition OFF and key inserted)1. Key Unlock Warning Switch
2. Door Courtesy Switch
3. Wire HarnessBE±31
BE±60
±
Key unlock warning system does not operate.
(The buzzer sounds when the ignition key is ACC or ON)1. Ignition Switch
2. Wire HarnessBE±31
±
HEADLIGHT AND TAILLIGHT SYSTEM:
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
HINT:
To inspect the bulb and light control ECU, replace them with the ones working normally and judge whether
they work normally or not.
SymptomSuspect AreaSee page
ºAutomatic light control systemº does not operate.
1. Automatic Light Control Sensor
2. Light Control Switch
3. Door Courtesy Switch
4. Wire Harness
5. Body No.2 ECUBE±37
BE±37
BE±60
±
DI±820
Auto turn±off system does not operate when the driver's door is
opened.1. Drivers Door Courtesy SwitchBE±60
Auto turn±off system:
Headlight and taillight do not come on.1. Body ECU No.2
2. Wire HarnessDI±820
±
Auto turn±off system:
Headlight and taillight stay on.1. Body ECU No.2
2. Wire HarnessDI±820
±
USA:
SymptomSuspect AreaSee page
Only one headlight comes on.
1. Bulb
2. *Light Control ECU
3. Wire Harness±
±
±
ºLO±Beamº does not light (All).
1. Headlight Control Relay
2. *Light Control ECU
3. Wire HarnessBE±37
±
±
ºLO±Beamº does not light (One side).
1. Bulb
2. H±LP L±LWR Fuse
3. H±LP R±LWR Fuse
4. *Light Control ECU
5. Wire Harness±
BE±21
BE±21
±
±
ºHI±Beamº does not light (All).1. Headlight Dimmer Switch
2. Wire HarnessBE±37
±

± 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
±