2000 LEXUS GS400 radio

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)

6RadioPOOR RECEPTION
Is the condition bad in comparison with other vehicles?
Are there any additional installation parts?
(Sun shade film, telephone antenna, etc.)
Check if there is any scratch and breaking of a wire on
the glass antenna and the defogger pattern.
(visual check. tester)
(See page
BE±190)
Is the contact of the plug jack of the radio OK?
Does the condition get better by using the outer
antenna (such as pillar antenna)?
Is the contact of the antenna terminal on the glass
surface and the defogger terminal?
Is the continuity of the antenna cord OK?
Check the grounding of the antenna, antenna cord,
choke coil, and noise filter. (See page BE±190)
Does the condition get better by replacing
the choke coil?
Does the condition get better by replacing the
antenna cord?Take a measure for contact. An electric wave environment is bad.
Does the condition get better if
removing them?
Influence of additional installation parts.
Repair. (See page BE±108)
Check the radio.
Take a measure for contact.
Grounding failure. Replace the antenna cord.
Replace the choke coil.
Replace the antenna cord. Ye s
No
Exchange the glass.Ye s
Ye s
Ye s
Ye s
Ye s
Ye s
Ye s
Ye s No
No
No
NoNo
No
No
No
NG
OK
Ye s BE±202
± BODY ELECTRICALAUDIO SYSTEM
2503 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

7 Radio SOUND QUALITY POOR
Ye sNo
Ye s
NG
OK Is sound quality always bad?
Is tape player operating normally?Poor signals, poor location.
Radio assembly faulty.
Install properly.
Speaker faulty. Is tape player operating normally?
Is speaker properly installed?
Radio assembly or power amplifier faulty.
Recheck system after repair. Temporarily install another speaker. Functions OK?Is sound quality bad in certain
areas only?
Radio assembly or power
amplifier faulty.
Can cassette tape be inserted in tape player?
Check if RADIO No.1 fuse is OK?Radio assembly faulty.
Replace fuse.
+B wire harness faulty.
GND faulty.
Power amplifier faulty. 8 Radio PRESET MEMORY DISAPPEARSNo
Radio assembly faulty.
No
NoNo NoYe s
Ye s
Ye s
Power amplifier faulty.
Radio assembly faulty.Ye s
Ye sYe s
No
No
No NG
NG
OKOKYe s
Check if GND (wire harness side) of power amplifier
grounded normally? Is power supplied to +B terminal of power amplifier?
Check if GND (wire harness side) of radio assembly
grounded normally? Is power supplied to +B terminal of radio assembly?
± BODY ELECTRICALAUDIO SYSTEM
BE±203
2504 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

9 Tape Player CASSETTE TAPE CANNOT BE INSERTED
Ye s
No NG Is there a foreign object inside tape player?
Is auto search button radio operating normally?
Check if RADIO No.1 fuse is OK?
Radio assembly faulty.Radio assembly faulty. Remove foreign object.
Replace fuse.
+B wire harness faulty.
GND faulty.
Power amplifier faulty.
Power amplifier faulty. Ye s No
No
OK
Ye s
OK
Ye s
OKNG
No
NG
10 Tape Player CASSETTE TAPE INSERTED, BUT NO POWER
Is radio operating normal?
Check if RAD No.2 fuse is OK?
ACC wire harness faulty.
Check if RADIO No.1 fuse is OK?Radio assembly faulty.
Replace fuse.
Replace fuse.
+B wire harness faulty.
Power amplifier faulty.
Radio assembly faulty.No
No
No
No OK
OKYe s
Ye s
Ye sYe s
NG
NG Check if GND (wire harness side) of power amplifier
grounded normally? Is power supplied to +B terminal of power amplifier?
Check if GND (wire harness side) of radio assembly
grounded normally? Is power supplied to +B terminal of radio assembly?
Is power supplied to +B terminal of radio assembly? Is power supplied to ACC terminal of power amplifier?
Is power supplied to ACC terminal of radio assembly? BE±204
± BODY ELECTRICALAUDIO SYSTEM
2505 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)