2000 LEXUS GS400 CD changer

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.

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.

BE0GD±10
I01372
Ignition SwitchRadio Assembly Tweeter
Front Speakers
Rear Speakers
Tweeter
Radio Assembly LEXUS Navigatioin
System Woofer
Power Amplifier
(NAKAMICHI made)
Driver Side Junction Block

RAD NO.2 FuseEngine Room No.1
Junction Block

ECU±B1 Fuse

RAD NO.1 Fuse
Passenger Side
Junction Block

DOME Fuse CD Auto ChangerCD Magazine
Power Amplifier
(PIONEER made)
BE±216
± BODY ELECTRICALAUDIO SYSTEM
2517 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
LOCATION
The vehicle shown in this illustration is ºGS400º.
All components of ºGS300º other than the ones used for engine are same as ºGS400º.

BE0GE±03
I04310
Wire Harness Side
I04189
Wire Harness Side
Connector ºBº
Connector ºDº Connector ºCº Connector ºAº
± BODY ELECTRICALAUDIO SYSTEM
BE±217
2518 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. Except 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
8 ± GroundConstantContinuity
5 ± GroundConstantBattery positive voltage
10 ± GroundIgnition switch LOCKNo voltage
10 ± GroundIgnition switch ACC or ONBattery 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.
2. Except NAKAMICHI made:
INSPECT POWER AMPLIFIER CIRCUIT
Disconnect the connector from power amplifier and inspect the
connector on the wire harness side.
Tester connectionConditionSpecified condition
B7 ± GroundConstantContinuity
C12 ± GroundIgnition switch LOCK and radio switch ONNo voltage
C12 ± GroundIgnition switch ACC or ON and radio switch ONBattery positive voltage
B4 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.

I04190
Wire Harness Side
Connector ºAº Connector ºBº BE±218
± BODY ELECTRICALAUDIO SYSTEM
2519 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. Except 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
A2 ± GroundConstantContinuity
A4 ± GroundConstantBattery positive voltage
A1 ± GroundIgnition switch LOCKNo voltage
A1 ± GroundIgnition switch ACC or ONBattery positive voltage
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.

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.

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.)