Lexus RX300 (MCU15). Service manual - part 153

DTC

Diagnosis item

Diagnosis content

Countermeasure
and inspected parts

System
Check

Diagnosis

memory

X

f

f

f

X

AMP
(440)

D1

D4

FF

Diagnosis no response

Result of diagnosis is not
issued from start to finish.

Stereo component
amplifier check.

f

Parts
Name

Transmitter error

68

69

D1

D4

FF

Elevator error

Clamp error

Periodic communication
error

Diagnosis no response

An error occurs in
elevator of CD changer
elevator.
An error occurs in CD
changer clamp.

Result of diagnosis is not 
issued from start to finish.

X

X

f

X

f

f

f

f

f

X

Transmitter error

CD
(240)
(360)

Center
Cluster
(1c4)

f

D1

f

Transmitter error

X

f

D4

Periodic
communication
error

Center Cluster Check

Multi
Display
(1d4)

f

D1

f

Transmitter error

Multi–Display Check

X

f

D4

21

22

ROM error

RAM error

There is an error on
internal ROM.

There is an error on
internal RAM.

f

X

f

X

Periodic
communication
error

Periodic
communication
error

CD changer check.

D Radio receiver check.
D Wire harness check.

D Radio receiver check.
D Wire harness check.

Stereo component
amplifier check.

D Radio receiver check.
D Wire harness check.

D Radio receiver check.
D Wire harness check.

Multi–Display Check

CD changer check.

Communication with the 
equipment that is 
communicating has failed 
successively.

Communication with the 
equipment that is 
communicating has failed 
successively.

Communication with the 
equipment that is 
communicating has failed 
successively.

Communication with the 
equipment that is 
communicating has failed 
successively.

Connection confirmation 
has not come from the 
equipment that is 
communicating

Connection confirmation 
has not come from the 
equipment that is 
communicating

Connection confirmation 
has not come from the 
equipment that is 
communicating

Connection confirmation 
has not come from the 
equipment that is 
communicating

–

BODY ELECTRICAL

AUDIO SYSTEM (Except Europe)

BE–159

LEXUS RX300   (RM785E)

( ): w/ Navigation system

1

Radio

RADIO NOT OPERATING WHEN POWER SWITCH TURNED TO ”ON”

+ 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?

Yes

NG

No

OK

No

No

No

No

OK

OK

OK

Yes

Yes

Yes

Yes

NG

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–160

–

BODY ELECTRICAL

AUDIO SYSTEM (Except Europe)

LEXUS RX300   (RM785E)

2

Radio

DISPLAY INDICATES WHEN POWER SWITCH TURNED TO
”ON”, BUT NO SOUND (INCLUDING ”NOISE”) 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?

Yes

NG

No

OK

No

No

No

No

OK

OK

OK

Yes

Yes

Yes

Yes

NG

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?

Yes

Yes

No

No

No

Yes

Power 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 ELECTRICAL

AUDIO SYSTEM (Except Europe)

BE–161

LEXUS RX300   (RM785E)

Speaker wire harness faulty.

Is tape player operating normally?

Yes

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?

Yes

Yes

No

Yes

No

No

3

Radio

NOISE PRESENT, BUT AM–FM NOT OPERATING

Go to No.25

Radio faulty.

If radio side faulty.

BE–162

–

BODY ELECTRICAL

AUDIO SYSTEM (Except Europe)

LEXUS RX300   (RM785E)