LEXUS GS400 2000 Service Repair Manual

BE0HD±04
I05186
ºBrightº ºDarkº1
2
3
4
Black coloured tape
I04048
Wire Harnes Side BE±182
± BODY ELECTRICALELECTRO CHROMIC MIRROR SYSTEM
2483 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT ELECTRO CHROMIC INNER MIRROR OP-
ERATION
(a) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 4.
(b) Connect the positive (+) lead from the voltmeter to termi-
nal 2 and the negative (±) lead to terminal 3.
(c) Attach a black coloured tape to forward sensor to prevent
it from sensing.
(d) When the mode is turned to AUTO, check that indicator
light lights up.
(e) Light up the mirror with an electric light, and check that
there is battery positive voltage and mirror surface
changes ºbrightº to ºdarkº.
If operation is not as specified, replace the inner mirror.
2. INSPECT ELECTRO CHROMIC INNER MIRROR CIR-
CUIT
Disconnect the connector from the mirror and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
4 ± GroundConstantContinuity
1 ± GroundIgnition switch LOCK or ACCNo voltage
1 ± GroundIgnition switch ONBattery positive voltage
If circuit is not as specified, inspect the circuits connected to
other parts.

I04178
ºBrightº
ºDarkºw/o Memory
2 1
I04179
ºBrightº
ºDarkºw/ Memory
5 4
± BODY ELECTRICALELECTRO CHROMIC MIRROR SYSTEM
BE±183
2484 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. w/o Driving position memory:
INSPECT ELECTRO CHROMIC OUTER MIRROR OP-
ERATION
(a) Disconnect the outer mirror connector.
(b) Connect the positive (+) lead from the dry cell battery to
terminal 2 and the negative (±) lead to terminal 1, then
check that the mirror surface changes to ºdarkº.
(c) Check the mirror turns to ºbrightº after disconnecting the
battery.
If operation is not as specified, replace the mirror assembly.
4. w/ Driving position memory:
INSPECT ELECTRO CHROMIC OUTER MIRROR OP-
ERATION
(a) Disconnect the outer mirror connector.
(b) Connect the positive (+) lead from the dry cell battery to
terminal 5 and the negative (±) lead to terminal 4, then
check that the mirror surface changes to ºdarkº.
(c) Check the mirror turns to ºbrightº after disconnecting the
battery.
If operation is not as specified, replace the mirror assembly.

BE0GH±10
I01370
Ignition Switch
Seat Heater SwitchPassenger Side Junction Block
SEAT±HTR Fuse
Seat Heater CushionSeat Heater Back
Seat Heater Cushion Inner
BE±184
± BODY ELECTRICALSEAT HEATER SYSTEM
2485 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
SEAT HEATER SYSTEM
LOCATION

BE0GI±07
I04180e±6±2±H
I04181
4 6
L
R Switch
L Switch
I04182
Seat back connector ºAº
Seat cushion
inner
connector ºBº
± BODY ELECTRICALSEAT HEATER SYSTEM
BE±185
2486 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT SEAT HEATER SWITCH CONTINUITY
Switch positionTester connectionSpecified condition
Right side3 ± 4 ± 6Continuity
OFF±No continuity
Left side2 ± 4 ± 6Continuity
Illumination circuit1 ± 5Continuity
If continuity is not as specified, replace the switch.
2. INSPECT SEAT HEATER INDICATOR LIGHT OPERA-
TION
(a) Connect the positive (+) lead from the battery to terminal
6 and the negative (±) lead to terminal 4.
(b) Push the seat heater switch Right or Left side and check
that the indicator light lights up.
If operation is not as specified, replace the switch and inspect
the circuits connected to other parts.
3. INSPECT SEAT HEATER CUSHION CONTINUITY
(a) Heat the thermostat with a light.
(b) Inspect the seat heater cushion continuity between termi-
nals, as shown.
Tester connectionConditionSpecified condition
A2 ± B1ConstantContinuity
A1 ± A2Seat heater temperature below 25 °C (77 °F)Continuity
B1 ± B2Seat heater temperature above 45 °C (113 °F)No continuity
If continuity is not as specified, replace the seat cushion pad.

I01824
Wire Harness Side
e±2±1
2 1
I01824
Wire Harness Side
e±2±1
2 1 BE±186
± BODY ELECTRICALSEAT HEATER SYSTEM
2487 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. INSPECT SEAT HEATER CUSHION CONTINUITY
Inspect the seat heater inner cushion and front cushion continu-
ity between terminals, as shown.
Tester connectionConditionSpecified condition
1 ± Body groundSeat heater switch ONBattery positive volatage
If continuity is not as specified, replace the seat back pad.
5. INSPECT SEAT BACK CONTINUITY
Inspect the seat back continuity between terminals, as shown.
Tester connectionConditionSpecified condition
2 ± Body groundConstantContinuity
If continuity is not as specified, replace the seat back pad.

BE0GF±05
I01371
Fuel Lid Opener Switch
Driver Side Junction Block

FUEL OPN Fuse
Fuel Lid Opener Motor
± BODY ELECTRICALFUEL LID OPENER SYSTEM
BE±187
2488 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
FUEL LID OPENER SYSTEM
LOCATION

BE0GG±03
I04184
I04185
Wire Harness Side
I041862 3
BE±188
± BODY ELECTRICALFUEL LID OPENER SYSTEM
2489 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT FUEL LID OPENER SWITCH CONTINUITY
(a) Check that continuity exists between terminals with the
switch ON (Lever pulled).
(b) Check that no continuity exists between terminals with the
switch OFF (Lever free).
If continuity is not as specified, replace the switch assembly.
2. INSPECT FUEL LID OPENER SWITCH CIRCUIT
Disconnect the connector from the switch and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
1 ± GroundConstantContinuity
2 ± GroundConstantBattery positive voltage
If circuit is not as specified, inspect the circuits connected to oth-
er parts.
3. INSPECT FUEL LID OPENER SOLENOID OPERATION
(a) Connect the positive (+) lead from the battery to terminal
2 and negative (±) lead to terminal 3.
(b) Check that the solenoid operates in the fuel lid opening.
If operation is not as specified, replace the solenoid.

I04187
Wire Harness Side
± BODY ELECTRICALFUEL LID OPENER SYSTEM
BE±189
2490 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. INSPECT FUEL LID OPENER MOTOR CIRCUIT
Disconnect the connector from the switch and inspect the con-
nector on the wire harness side, as shown.
Tester connectionConditionSpecified condition
3 ± GroundConstantContinuity
2 ± GroundFuel lid opener switch ON (Lever pulled)Battery positive voltage
If circuit is not as specified, inspect the circuits connected to oth-
er parts.

BE10X±03
I10058
Radio Receiver Assembly Power Amplifier CD Auto Changer BE±190
± BODY ELECTRICALAUDIO SYSTEM
2491 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
AUDIO SYSTEM
DESCRIPTION
1. OUTLINE OF AVC±LAN
(a) What is AVC±LAN?
AVC±LAN is the abbreviation, which stands for Audio Visual Communication±Local Area Network.
This is a unified standard co±developed by 6 audio manufactures associated with Toyota Motor Corpo-
ration.
The Unified standard covers signals, such as audio signal, visual signal, signal for switch indication
and communication signal.
(b) Objectives
Recently the car audio system has been rapidly developed and functions have been changed drasti-
cally. The conventional system has been switched to the multi±media type such as a navigation sys-
tem. At the same time the level of customers needs to audio system has been upgraded. This lies be-
hind this standardization.
The concrete objectives are explained below.
(1) When products by different manufactures were combined together, there used to be a case that
malfunction occurred such as sound did not come out. This problem has been resolved by stan-
dardization of signals.
(2) Various types of after market products have been able to add or replace freely.
(3) Because of the above (2), each manufacture has become able to concentrate on developing
products in their strongest field. This has enabled many types of products provided inexpensive-
ly.
(4) Conventionally, a new product developed by a manufacture could not be used due to a lack of
compatibility with other manufactures products. Because of this new standard, users can enjoy
compatible products provided for them timely.
The above descriptions are the objectives to introduce AVC±LAN. By this standardization, development of
new products will no longer cause systematic errors. Thus, this is very effective standard for a product in the
future.
HINT:
When +B short or GND short is detected in AVC±LAN circuit, communication stops. Accordingly the
audio system does not function normally.
When audio system is not equipped with a navigation system, audio head unit is the master unit. (When
audio system is equipped with a navigation system, navigation ECU is the master unit.)
The car audio system using AVC±LAN circuit has a diagnosis function.
Each product has its own specified numbers called physical address. Numbers are also allotted to
each function in one product, which are called logical address.

I07735
± BODY ELECTRICALAUDIO SYSTEM
BE±191
2492 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. DIAGNOSIS FUNCTION (PIONEER made)
Error codes over tuner and connected equipment are displayed on the screen of tuner.
(a) Diagnosis start±up
For shifting to diagnosis mode, push ºCDº switch 3 times with pressing º1º and º6º of PRESET switch
at the same time while the audio power is OFF and ACC is ON.
To exit from diagnosis mode, press ºCDº switch for 2 seconds or turn the ignition key OFF.
(When º1±190º is displayed, the mode is transferred to LAN check mode.)
(b) LAN check
When starting up the diagnosis mode, the mode turns to LAN check mode, the screen displays the
code numbers (physical address) of tuner and connected equipment. Smaller codes are displayed in
order, displayed code numbers are switched by operating TUNE ºUPº or ºDOWNº switch. In LAN check
mode, by pressing º5º of PRESET switch for more than 2 secs., diagnosis memory of each equipment
can be deleted, when deletion is completed, the mode returns to LAN check mode.
Code No. (physical address) List
Code No. (physical address)Equipment name
190Radio receiver assembly (Audio head unit)
240CD changer (in Luggage room)
360CD changer (in center console and glove compartment box)
440Power amplifier
(c) System check
When pressing º1º of PRESET switch in LAN check mode, the mode turns to the system check
mode, the system performs self diagnosis of connected equipment and displays the re-
sults.(ºSYSº (showing the system is under detection) is displayed.)
Perform the operation shown in the following illustration, then read the result of the inspection.