2000 LEXUS GS400 radio

AC0XR±01
I03746
Electrical Multi Vision:
I03747
Except Electrical Multi Vision:
I04720
Except Electrical Multi Vision:Electrical Multi Vision: AC±86
± AIR CONDITIONINGAIR CONDITIONING CONTROL ASSEMBLY
2771 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
AIR CONDITIONING CONTROL
ASSEMBLY
REMOVAL
1. REMOVE THESE PARTS:
(a) No.2 register
(b) Cluster finish panel
(See page BO±91)
2. REMOVE A/C CONTROL ASSEMBLY WITH RADIO
Remove the 4 bolts and pull out the A/C control assembly, then
disconnect the connectors.
3. REMOVE A/C CONTROL ASSEMBLY FROM RADIO
Remove the 8 bolts, 2 screw and 2 brackets, then remove the
A/C control assembly.

BE±2
± BODY ELECTRICALBODY ELECTRICAL SYSTEM
2303 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. MICRO COMPUTER PRESET DRIVING POSITION SYSTEM
Power Seat Control System
Power Mirror Control System
Power Tilt and Telescopic Steering System
If the battery negative (±) terminal is disconnected, the preset driving positions stored in memory are erased,
so be sure to note the positions and reset them after the battery terminal is reconnected.
5. AUDIO SYSTEM

If the negative (±) terminal cable is disconnected from the battery, the preset AM, FM 1 and FM 2 sta-
tions stored in memory are erased, so be sure to note the stations and reset them after the negative
(±) terminal cable is reconnected to the battery.

If the negative (±) terminal cable is disconnected from the battery, the ºANTI±THEFT SYSTEMº will
operate when the cable is reconnected, but the radio, tape player and CD player will not operate. Be
sure to input the correct ID number so that the radio, tape player and CD player can be operated again.
6. MOBILE COMMUNICATION SYSTEM
If the vehicle is equipped with a mobile communication system, refer to precautions in the IN section.

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.

H: This shows the equipment has a diagnosis code.
190: Physical address
1: This is the number allotted to the diagnosis code
that occurred.
21: DTC No.
Last Code No.: NO DTC No.
Pressing TURN ºDOWNº
Pressing TURN ºUPº
.
.
..
.
.1: This is the number allotted to the diagnosis code
that occurred. BE±192
± BODY ELECTRICALAUDIO SYSTEM
2493 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HINT:
It sometimes takes approx. 40 secs. till the system inspection is completed.
The chart below is an example of when diagnosis code º21º appears on the physical address (190)
equipment. (ROM error occurs on the radio receiver.)
The smaller code numbers (physical address) are displayed in order (code No., diagnosis code, sup-
port code of diagnosis code (object equipment)).
When no error is detected in the system, º00º is displayed.
When an error code is detected, up to 6 codes per one system are displayed. Pressing TUNE ºUPº
or ºDOWNº switches the display.
In the system check mode, when pressing º6º of PRESET switch the mode returns to LAN check mode.
(d) Diagnosis memory
(1) In LAN check mode, when pressing º2º of PRESET switch the mode turns to the diagnosis
memory mode. (ºCODEº is displayed.)
The results of self diagnosis performed over tuner and connected equipment are memorized and
displayed.
(2) Perform the operation shown in the following illustration, then read the result of the inspection.
HINT:
The smaller code numbers (physical address) are displayed in order (code No. , periodic communica-
tion number when error occurs, diagnosis code, and support code of diagnosis code (object equip-
ment)).
When no error is detected in the system, º00º is displayed. When an error code is detected, up to 6
codes per one system are displayed. Pressing TUNE ºUPº or ºDOWNº switches the display. Each diag-
nosis code is same as code in the system check mode.
When pressing º6º of PRESET switch, the mode returns to LAN check mode.
The following illustration below is an example of when diagnosis code ºD1º appears on the code (190)
and (240 or 360) equipment. (Communication error occurs between the radio receiver and CD chang-
er.)

DTCDiagnosis item
Diagnosis contentCountermeasure
and inspected parts
D1
FF
60Radio receiver check. FM tuner error
42
50Cassette error
Transmitter error
Diagnosis no response
CD error
61
EJECT error
62
63
64
67DISC inside out/flaw
Pickup temperature
detection
Excessive current
detection
Tray insertion/
discharging errorThere is an error in FM tuner.
There is an error in cassette
deck.
Communication with the
equipment that is
communicating has failed
successively.
Result of diagnosis is not
issued from start to finish.
Error codes other than
61±69 are detected.
CD is not ejected.
CD is inserted inside
out or it has a flaw.
High temperature of CD
changer is detected.
Excessive current to
CD changer is detected.
An error occurs in insertion
and discharging operation of
CD changer tray.Radio receiver check.
CD changer check.
CD changer check.
Magazine check.
CD check.
CD changer check.
CD changer check.
Magazine check. Radio receiver check.
Wire harness and
connecter check.
CD
(240)
(360)System
Check
Diagnosis
memory
X
 X

X
X
X
X
X
X
X



 Head
Unit
(190) Parts
Name
51Cassette eject errorCassette can not be ejected
from Head Unit.
 X
D2Periodic
communication
no response
Error in periodic
communication. Wire harness and
connector X

68
D1
D4Elevator error
Periodic communication
errorAn error occurs in
elevator of CD changer
elevator.X

X

 Transmitter error
 Radio receiver check.
 Wire harness check.
CD changer check.
Communication with the
equipment that is
communicating has failed
successively.
Connection confirmation
has not come from the
equipment that is
communicating BE±194
± BODY ELECTRICALAUDIO SYSTEM
2495 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. DIAGNOSIS CODE LIST
If there is ºOº in the column of system check, an error can be detected when the mode is switched to
the system check mode.
If there is ºOº in the column of diagnosis mode, each unit is monitoring whether or not it has failure.
In case of detectng failure, it memorizes DTC.

DTC Diagnosis itemDiagnosis contentCountermeasure
and inspected partsSystem
CheckDiagnosis
memory
X
 AMP
(440)D1
D4Stereo component
amplifier check. Parts
Name
Transmitter error
Periodic
communication
error
 Radio receiver check.
 Wire harness check.
Communication with the
equipment that is
communicating has failed
successively.
Connection confirmation
has not come from the
equipment that is
communicating
± BODY ELECTRICALAUDIO SYSTEM
BE±195
2496 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

BE0GC±05
BE±196
± BODY ELECTRICALAUDIO SYSTEM
2497 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
TROUBLESHOOTING
NOTICE:
When replacing the internal mechanism (computer part) of the audio system, be careful that no part
of your body or clothing comes in contact with the terminals of the leads from the IC, etc. of the re-
placement part (spare part).
HINT:
This inspection procedure is a simple troubleshooting which should be carried out on the vehicle during sys-
tem operation and was prepared on the assumption of system component troubles (except for the wires and
connectors, etc.).
Always inspect the trouble taking the following items into consideration.
Open or short circuit of the wire harness
Connector or terminal connection fault
For audio systems with anti±theft system, troubleshooting items marked ( * ) indicate that ºTrou-
bleshooting for ANTI±THEFT SYSTEMº should be carried out first.
ProblemNo.
RadioRadio not operating when power switch turned to 'ON'.1
Display indicates when power switch turned to 'ON', but no sound (including
'noise') is produced.2
Noise present, but AM ± FM not operating.3
Any speaker does not work.4
Any AM or FM does not work.5
Few preset turning bands.5
Reception poor.6
Sound quality poor.7
Preset memory disappears.8
Tape PlayerCassette tape cannot be inserted.9
Cassette tape inserted, but no power.10
Power coming in, but tape player not operating.11
Any speaker does not work.12
Sound quality poor.13
Tape jammed, malfunction with tape speed or auto±reverse.14
Cassette tape will not eject.15
CD PlayerCD cannot be inserted.16
CD inserted, but no power.17
Power coming in, but CD player not operating.18
Sound jumps.19
Sound quality poor (Volume faint).20
Any speaker does not work.21
CD will not be ejected.22
Power AmplifierNo power coming in.23
Power coming in, but power amplifier not operating.24
Any speaker does not work.25
NoiseNoise occurs26
Noise produced by vibration or shock while driving.27
Noise produced when engine starts.28
The term ºAMº includes LW,MW and SW, and the term ºFWº includes UKW.