lock LEXUS GS400 2000 Service Repair Manual

BE±12
± BODY ELECTRICALTROUBLESHOOTING
2313 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) The system does not operate when the ignition switch is turned to
ACC without using a key or transmitter.
1. Ignition Switch
2. Key Unlock Warning Switch
3. Transmitter
4. Wire Harness
5. Body No.1 ECUBE±31
BE±31
BE±157
±
DI±776
Some of the system does not operate.
(Headlight does not light up.)
1. Headlight System
2. Wire Harness
3. Body No.2 ECU
4. Body No.1 ECUBE±3
±
DI±820
DI±776
Some of the system does not operate.
(Taillight does not light up.)
1. Taillight System
2. Wire Harness
3. Body No.2 ECU
4. Body No.1 ECUBE±3
±
DI±820
DI±776
Some of the system does not operate.
(Theft Deterrent Horn or Horn does not sound.)
1. HORN Fuse
2. Theft Deterrent Horn
3. Horn
4. Horn Relay
5. Wire Harness
6. Body No.1 ECUBE±21
BE±150
BE±250
BE±250
±
DI±776
While the warning is given, the system cannot be canceled by
unlocking the door with key or transmitter.1. Door Key Lock and Unlock Switch
2. Wire Harness
3. Body No.1 ECUBE±131
±
DI±776
While the warning is given, the system cannot be canceled by
turning the ignition switch to ACC or ON with key.
1. Ignition Switch
2. Key Unlock Warning Switch
3. RAD NO.2 Fuse
4. ECU±IG Fuse
5. Wire Harness
6. Body No.2 ECU
7. Body No.1 ECUBE±31
BE±31
BE±21
BE±21
±
DI±820
DI±776
The system operates for more than 60 seconds.Body No.1 ECUDI±776
WIRELESS DOOR LOCK CONTROL SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
HINT:
Troubleshooting of the wireless door lock control system is based on the premise that the door lock
control system is operating normally. Accordingly, before troubleshooting the wireless door lock control
system, first make certain that the door lock control system is operating normally.
If the trouble still reappears even though there are no abnormalities in any of the other circuits, then
check and replace the Wireless Door Lock Control Receiver as the last step.
SymptomSuspect AreaSee page
All functions of wireless door lock control system do not operate.
1. Transmitter
2. Wireless Door Lock Control Receiver
3. Wire Harness
4. Body No.1 ECUBE±157
BE±157
±
DI±776
Wireless door lock operates, but the buzzer does not sound.
(The buzzer does not sound when the customize function prohib-
its.)1. Wireless Door Lock Buzzer
2. Wireless Door Lock Control Receiver
3. Wire HarnessBE±157
BE±157
±

± BODY ELECTRICALTROUBLESHOOTING
BE±13
2314 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
POWER SEAT CONTROL SYSTEM
SymptomSuspect AreaSee page
Both Driver and Passenger Power seats do not operate.
(Door lock does not operate.)1. ALT M±Fuse
2. Wire HarnessBE±21
±
Driver's seat does not operate.
1. P/SEAT (D) Fuse
2. Power Seat Switch (D)
3. Wire HarnessBE±21
BE±167
±
Passenger's seat does not operate.
1. P/SEAT (P) Fuse
2. Power Seat Switch (P)
3. Wire HarnessBE±21
BE±167
±
ºSlide operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Slide Motor (D, P)BE±167
±
BE±167
ºFront Vertical Operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Front Vertical Motor (D, P)BE±167
±
BE±167
ºLifter Operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Lifter Motor (D, P)BE±167
±
BE±167
ºReclining Operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Reclining Motor (D, P)BE±167
±
BE±167
ºLumbar Support Operationº does not operate.
1. Power Seat Switch (D, P)
2. Wire Harness
3. Lumbar Support Motor (D, P)BE±167
±
BE±167
(D): Driver's Seat
(P): Passenger's Seat
POWER MIRROR CONTROL SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
w/ Driving Position Memory System:
SymptomSuspect AreaSee page
Both right and left mirrors do not operate.
1. Mirror Switch
2. Wire Harness
3. Body No.2 ECUBE±176
±
DI±820
Only one side of mirror does not operate.
1. Mirror Motor
2. Wire Harness
3. Driver and Passenger Door ECUBE±176
±
DI±856
DI±889
The mirror does not return to the memorized position.
1. Mirror Position Sensor
(Position is not set)
2. Wire Harness
3. Power Seat Control ECU
BE±176
±
DI±683
The memorized position is moved.
1. Mirror Position Sensor
(Position is not set)
2. Wire Harness
BE±176
±

BE±14
± BODY ELECTRICALTROUBLESHOOTING
2315 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
w/o Driving Position Memory System:
SymptomSuspect AreaSee page
Mirror does not operate.
1. Mirror Switch
2. Wire Harness
3. Body No.2 ECU
4. Driver and Passenger Door ECUBE±176
±
DI±820
DI±856
DI±889
Mirror operates abnormally.
1. Mirror Switch
2. Mirror Motor
3. Wire Harness
4. Body No.2 ECU
5. Driver and Passenger Door ECUBE±176
BE±176
±
DI±820
DI±856
DI±889
ELECTRO CHROMIC MIRROR SYSTEM
SymptomSuspect AreaSee page
Electro Chromic Inner Mirror does not operate.
1. ECU±IG Fuse
2. Electro Chromic Inner Mirror
3. Wire HarnessBE±21
BE±182
±
Electro Chromic Outer Mirror does not operate.
1. ECU±IG Fuse
2. Electro Chromic Outer Mirror
3. Electro Chromic Inner Mirror
4. Wire HarnessBE±21
BE±182
BE±182
±
SEAT HEATER SYSTEM
SymptomSuspect AreaSee page
Seat heaters do not operate.
(Driver's and Passenger's)
1. SEAT HTR Fuse
2. Seat Heater Switch (D, P)
3. Wire Harness
4. Seat HeaterBE±21
BE±185
±
BE±185
Driver's seat heater does not operate.1. Seat Heater Switch (D, P)
2. Wire HarnessBE±185
±
Passenger's seat heater does not operate.1. Seat Heater Switch (D, P)
2. Wire HarnessBE±185
±
Seat heater temperature is too hot.Seat HeaterBE±185
FUEL LID OPENER SYSTEM
SymptomSuspect AreaSee page
Fuel lid opener system does not operate.
1. FUEL OPN Fuse
2. Fuel Lid Opener Switch
3. Fuel Lid Opener Motor
4. Wire HarnessBE±21
BE±188
BE±188
±
AUDIO SYSTEM
SymptomSuspect AreaSee page
Audio system abnormal operation.TROUBLESHOOTINGSBE±196
CLOCK SYSTEM
SymptomSuspect AreaSee page
Passenger seat belt warning system does not light up.TROUBLESHOOTING NO.1BE±227
Clock will not operate.TROUBLESHOOTING NO.1BE±227
Clock loses or gains time.TROUBLESHOOTING NO.2BE±227

BE01L±11
I01349
Ignition SwitchKey Unlock Warning Switch
BE±30± BODY ELECTRICALIGNITION SWITCH AND KEY UNLOCK WARNING
SWITCH
2331 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
IGNITION SWITCH AND KEY UNLOCK WARNING SWITCH
LOCATION

BE0H4±04
I01256
1 2 3 4
5 6 7 8 LOCKACC
ON
START
I04031
From Back Side
± BODY ELECTRICALIGNITION SWITCH AND KEY UNLOCK WARNING
SWITCHBE±31
2332 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT IGNITION SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
LOCK±No continuity
ACC2 ± 3Continuity
ON2 ± 3 ± 4
6 ± 7Continuity
START1 ± 2 ± 4
6 ± 7 ± 8Continuity
If continuity is not as specified, replace the switch.
2. INSPECT IGNITION SWITCH CIRCUIT
Connect the switch connector and inspect the connector on
wire harness side from the back side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantBattery positive voltage
3 ± GroundIgnition switch ACC or ONBattery positive voltage
4 ± GroundIgnition switch ONBattery positive voltage
6 ± GroundIgnition switch ON or STARTBattery positive voltage
7 ± GroundConstantBattery positive voltage
8 ± GroundIgnition switch STARTBattery positive voltage
If circuit is not as specified, inspect the circuits connected to oth-
er parts.

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.

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.

I01255
1
2 3 4
From Back Side BE±44
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
2345 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
21. INSPECT AUTOMATIC LIGHT CONTROL SENSOR
CIRCUIT
Connector connected
Connect the wire harness side connector to the sensor and in-
spect wire harness side connector from the back side, as
shown.
HINT:

Ignition switch ON.

Light control switch AUTO.

Vehicle's surroundings are bright.
Tester connectionConditionSpecified condition
3 ± GroundConstantContinuity
1 ± GroundIgnition switch LOCK or ACCNo voltage
1 ± GroundIgnition switch ON9.5 V or more
Vehicle is under the direct sun light.
(Sensor is not covered)Taillight and Headlight are ON.
If circuit is as specified, try replacing the sensor with a new one.
If the circuit is not as specified, inspect the circuit connected to
other parts.