LEXUS GS400 2000 Service Repair Manual

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.)

H: This shows the equipment has a diagnosis code.
190: Physical address
1: This is the number allotted to the diagnosis code
that occurred.
Last Code No.
.
.
..
.
.
06: Periodic communication number of when
occurring in the diagnosis memory code.
Pressing TURN ºDOWNºPressing TURN ºUPº
21: Periodic communication number of when
occurring in the diagnosis memory code.
1: This is the number allotted to the diagnosis code
that occurred.
d1: DTC No.
1: This is the number allotted to the diagnosis code
that occurred.
360: Physical address
(Equipment that is communicating code)
± BODY ELECTRICALAUDIO SYSTEM
BE±193
2494 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(e) Diagnosis memory clear
(1) After error is fixed, start up the diagnosis mode.
(2) Continue pressing preset switch º5º for 2 secs. (CLr is displayed.)
(3) Press the preset switch º2º and transfer to the diagnosis memory mode and check that the normal
code (00) is output.

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.

V08418
Turn ignition Key from LOCK position to ACC position.
Troubleshooting for ANTI±THEFT SYSTEM
Display A:
ID Number is set.Display E:
ANTI±THEFT SYSTEM opera-
tion condition. (ID number input
error 10 times or more.)Display B
ºSECº display disappears after 1
second.Radio switch ON.
Take to designated radio
service station.Display BDisplay D
Refer to each
malfunction item.Normal
operation.
Radio switch ON. Normal operation.
Cancel ID number, refer to each malfunction item.
Ye s
No
OK
NG
ANTI±THEFT SYSTEM operation condition. (ID number input error 9 times or less.)
Input ID number to cancel ANTI±THEFT SYSTEM, and check display.
Display A"B Display B Display E
Display C"A
Radio switch ON.Refer to each
malfunction item.Take to designated
radio service station.ANTI±THEFT SYSTEM not can-
celled. (ID number input error 10
times or less.)
Display D
ANTI±THEFT SYSTEM cancelled.
Check audio system again.Normal operation.
OK
NG
Cancel ID number, refer to each malfunction item.
Liquid Crystal Display (LCD) or VFD for Audio System
Display ºAº Display ºBº Display ºCº
Display ºDº Example:Display ºEº
2 DIN Type
1 DIN TypeBlank
No Illumination
2 DIN Type
1 DIN Type 2 DIN Type
1 DIN Type Error Times2 DIN Type 1 DIN Type
Radio Display
1 DIN Type 2 DIN Type
HINT:

Refer to Owner's Manual for operation details of ANTI±THEFT SYSTEM.

When the ID number has been cancelled, reset the same number after completing the operation, or
inform the customer that it has been cancelled.
± BODY ELECTRICALAUDIO SYSTEM
BE±197
2498 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

1 Radio RADIO NOT OPERATING WHEN POWER SWITCH TURNED TO ºONº
+ B wire harness faulty.
GND faulty.
Power amplifier or ACC wire harness faulty.
Power amplifier or +B wire harness faulty.
GND faulty. Is tape player operating normally?
Check if RAD±No.2 fuse is OK?
Is power supplied to ACC terminal of power amplifier?Ye s
NG
No OK No
No
No
No OK
OK
OK Ye s
Ye s
Ye s
Ye sNG
NG
NG Check if RAD±No.1 fuse is OK?
Radio assembly faulty.Replace fuse.
ACC wire harness faulty.
Check if GND (wire harness side) to radio assembly is OK?
Radio assembly faulty.
Replace fuse.
Is power supplied to +B terminal of power amplifier?
Is power supplied to ACC terminal of radio assembly?
Is power supplied to +B terminal of radio assembly? Check if GND (wire harness side) of power amplifier
grounded normally? BE±198
± BODY ELECTRICALAUDIO SYSTEM
2499 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

2 RadioDISPLAY INDICATES WHEN POWER SWITCH TURNED TO
ºONº, BUT NO SOUND (INCLUDING ºNOISEº) IS PRODUCED
+ B wire harness faulty.
GND faulty.
Power amplifier faulty.
Speaker wire harness faulty. GND faulty. Is tape player operating normally?
Check if RAD±No.2 fuse is OK?Ye s
NG
No OK No
No
No
No OK
OK
OK Ye s
Ye s
Ye s
Ye sNG
NG
NG Check if RAD±No.1 fuse is OK?
Radio assembly faulty. Recheck system after repair.Replace fuse.
ACC wire harness faulty. Radio assembly faulty.
Replace fuse.
Does continuity exist in speaker wire harness?
Temporarily install another speaker. Functions OK?
Hiss noise from speaker?Ye s
Ye s NoNo
No Ye sPower amplifier faulty.
Power amplifier faulty.
Recheck system after repair. Speaker faulty.
Is power supplied to ACC terminal of power amplifier?
Check if GND (wire harness side) of power amplifier
grounded normally? Is power supplied to +B terminal of power amplifier?
Is power supplied to ACC terminal of radio receiver?
Is power supplied to +B terminal of radio receiver?
Check if GND (wire harness side) of power amplifier
grounded normally?
± BODY ELECTRICALAUDIO SYSTEM
BE±199
2500 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

Speaker wire harness faulty. Is tape player operating normally?
Ye s
No
Radio assembly faulty.
Recheck system after repair. Radio assembly faulty.
Temporarily install another speaker? Functions OK?
Power amplifier faulty. Recheck system after repair.Speaker faulty. 4 Radio ANY SPEAKER DOSE NOT WORK
Is hiss noise produced by non±functioning speaker?
Does continuity exist in speaker wire harness?Ye s
Ye s No
Ye s
NoNo 3 Radio NOISE PRESENT, BUT AM±FM NOT OPERATING
Go to No.25
Radio faulty. If radio side faulty.
BE±200
± BODY ELECTRICALAUDIO SYSTEM
2501 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

5 RadioANY AM OR FM DOES NOR WORK
FEW PRESET TUNING BANDS
Problem with radio wave signals or location?
Are both AM and FM defective?Radio assembly faulty.
Go to No.16
Is tape player operating normally? Radio assembly faulty.
Is power for the antenna being output from the radio assembly?
Hiss noise from speaker? Temporarily install another speaker. Functions OK?
Radio assembly faulty. Recheck system after repair.Speaker faulty.
Power amplifier faulty.
Recheck system after repair. Poor signals, poor location.
No
Ye s
Ye s No
No
NoYe s
Ye s
Ye s
Ye s
No
No
± BODY ELECTRICALAUDIO SYSTEM
BE±201
2502 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)