Lexus RX300 (MCU15). Service manual — part 157

CD player faulty.

Power amplifier faulty.
Recheck system after repair.

Temporarily install another speaker.
Function OK?

25

Power Amplifier

ANY SPEAKER DOES NOT WORK

Speaker wire harness faulty.

Speaker faulty.

Is hiss noise produced by non–functioning speaker?

Does continuity exist in speaker wire harness?

Is radio operating normally?

Yes

Yes

Yes

Yes

No

No

No

No

Radio assembly faulty.
Recheck system after repair.

–

BODY ELECTRICAL

AUDIO SYSTEM (Except Europe)

BE–175

LEXUS RX300 (RM785E)

26

Noise

NOISE OCCURS

No

Yes

NG

OK

Does the noise occur only in the radio?

Does the noise occur in a particular place?

Is there any additional installation part
around the glass imprinted antenna?
(Sun shade film, telephone antenna etc.)

Does the noise occur even pulling out the
antenna cord from the radio?

Does the noise occur even after pulling out the
antenna terminal on the glass surface?

Isn’t there any adhesive (Butyl rubber)
stuck on the bases of the antenna
terminal, defogger terminal and bus bar?

Check the grounding of the antenna,
antenna cord, coke coil, and noise filter.
(See page BE–149)

Does the noise occur even after pulling out
the defogger terminal?

Does the condition get better by replacing
the antenna cord.

Noise rediates directly to the antenna from the
generation source.

Does the condition get better by replacing
the choke coil?

Replace the antenna cord.

Replace the choke coil.

Interfering noise from the defogger line
and choke coil.

Grounding failure.

Failure of glass installation.
Must plane the butyl rubber.

Noise mixing into the antenna cable.

Check the radio.

Influence of the film or the noise radiation
of the additional installation part.

Does the noise stop by removing it?

An electric environment.

Refer to No.27.

(It occurs in the cassette and CD.)

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

No

No

No

BE–176

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BODY ELECTRICAL

AUDIO SYSTEM (Except Europe)

LEXUS RX300 (RM785E)

27

Noise

NOISE PRODUCED BY VIBRATION OR SHOCK WHILE DRIVING

No

Yes

Is speaker properly installed?

Noise is produced from static eletricity accumulating in the vehicle body.

With vehicles stationary lightly tap each system.
Is noise produced?

Install properly.

Each system faulty.

Is speaker properly installed?

No

No

Yes

Yes

28

Noise

NOISE PRODUCED WHEN ENGINE STARTS

No

Yes

Whistling noise which becomes high–pitched when
accelerator strongly depressed, disappears shortly
after engine stops.

Generator noise.

A/C noise.

Fuel gauge noise.

Horn noise.

Ignition noise.

Turn signal noise.

Washer noise.

Engine coolant temp. gauge noise.

Wiper noise.

Whining noise occurs when A/C is operating.

Scratching noise occurs during sudden acceleration, driving on rough

roads or when ignition switch is turned ON.

Clicking sound is heard when horn button is pressed, then
released. Whirring/grating sound is heard when pushed
continuously.

Murmuring sound stops when engine stops.

Tick–tack noise occurs in co–ordination with blinking
offlasher.

Noise occurs during window washer operation.

Scratching noise occurs while engine is running,
and continues a while even after engine stops.

Scraping noise in line with wiper beat.

Other type of noise

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

No

No

No

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BODY ELECTRICAL

AUDIO SYSTEM (Except Europe)

BE–177

LEXUS RX300 (RM785E)

BE0AZ–12

I19175

Engie Room J/B
D DOME Fuse
D RAD No. 1 Fuse

Tweeter

CD Auto Changer

Ignition Switch

Front Speaker

Auto Antenna

Center Cluster Integration
Panel
D Radio Assembly

Instrument Panel J/B
D RAD No. 2 Fuse

Rear Speaker

Power Amplifier

BE–178

–

BODY ELECTRICAL

AUDIO SYSTEM (Except Europe)

LEXUS RX300 (RM785E)

LOCATION