1999 TOYOTA CAMRY Antenna

The radio wave bands used in radio broadcasting are as follows:
Frequency
Designation
Radio wave
Modulation method
LF: Low frequency MF: Medium Frequency HF: High Frequency VHF: Very High FrequencyAmplitude modulationFrequency modulation 30 kHz
300 kHz3 MHz 30 MHz 300 MHz
LF
MFHFVHF
AM FM
BE0AX±03
BE2818
FM (Stereo)
FM (Monaural)
AM
BE2819
Fading
Ionosphere BE±86
± BODY ELECTRICALAUDIO SYSTEM
2306 Author: Date:
AUDIO SYSTEM
DESCRIPTION
1. RADIO WAVE BAND
2. SERVICE AREA
There are great differences in the size of the service area for AM
and FM monaural. Sometimes FM stereo broadcasts cannot be
received even through AM comes in very clearly.
Not only does FM stereo have the smallest service area, but it
also picks up static and other types of interference (ºnoiseº)
easily.
3. RECEPTION PROBLEMS
Besides the problem of static, there are also the problems
called ºfadingº, ºmultipathº and ºfade outº. These problems are
caused not by electrical noise but by the nature of the radio
waves themselves.

Fading
Besides electrical interference, AM broadcasts are
also susceptible to other types of interference, es-
pecially at night. This is because AM radio waves
bounce off the ionosphere at night. These radio
waves then interfere with the signals from the same
transmitter that reach the vehicle's antenna directly.
This type of interference is called ºfadingº.

BE2820
Multipath
BE2821
Fade Out
AM
FMNoise occurs at a specific place.
Strong possibility of foreign noise.
Noise occurs when listening to
faint broadcasting.
Noise occurs only at night.
Noise occurs while driving and
at a specific place.There is a case that the same program is broadcasted
from each local station and that may be the case you are
listening to different station if the program is the same.
Strong possibility of the beat from a distant broadcasting.
Strong possibility of multipath noise and fading noise
caused by the changes of FM waves.
± BODY ELECTRICALAUDIO SYSTEM
BE±87
2307 Author: Date:

Multipath
One type of interference caused by bouncing of ra-
dio waves off obstructions is called ºmultipathº. Mul-
tipath occurs when a signal from the broadcast
transmitter antenna bounces off buildings and
mountains and interferes with the signal that is re-
ceived directly.

Fade Out
Because FM radio waves are of higher frequencies
than AM radio waves, they bounce off buildings,
mountains, and other obstructions. For this reason,
FM signals often seem to gradually disappear or
fade away as the vehicle goes behind a building or
other obstructions. This is called ºfade outº.
4. NOISE PROBLEMS
(a) Questionnaire for noise:
It is very important for noise troubleshooting to have good un-
derstanding of the claims from the customers, so that make the
best use of following quenstionnaire and diagnose the problem
accurately.
HINT:
In the case that the noise occurrence condition does not meet
any of the above quenstionnaire, check based on the ºTrouble
Phenomenonº.
Refer to previous page for multipath and fading.

N21545
NoiseGlass Printed Antenna
Signal
Radio
Noise
Noise
Noise
Noise
N21546
to Radio
Battery
Choke Coil
Noise
BE±88
± BODY ELECTRICALAUDIO SYSTEM
2308 Author: Date:
(b) Matlers that require attention when checking:

Noise coming into the radio usually has no harm for
practical use as the noise protection is taken and it
is hardly thinkable for an extremely loud noise to
come in. When extremely loud noise comes into the
radio, check if the grounding is normal where the
antenna is installed.

Check if all the regular noise prevention parts are
properly installed and if there is any installation of
non±authorized parts and non±authorized wiring.

If you leave the radio out of tune (not tuning), it is
easy to diagnose the phenomenon as noise occurs
frequently.
(c) Antenna and noise:
Electronic signal received by the antenna will reach to the
radio transmitting through the core wire of the coaxial
cable. Any noise wave other than radio wave is mixed into
this core wire, that naturally causes noise in the radio and
poor sound quality. In order to prevent these noises from
mixing into the radio, the core wire inside the coaxial cable
is covered with a mesh wire called shield wire. This shield
wire shelters the noise and transmits it to the ground, thus
preventing noise from mixing in. If this shield wire has
grounding failure, that causes noise.
(d) Choke coil and noise:
The choke coil is connected in the rear window defogger
circuit. This is conneted so to prevent noise from mixing
into the radio by making the noise current included in the
power source of the rear window defogger flow to the
ground.

I00399
Plug (Main)Antenna
Terminal
(Main)
Plug (Sub)Antenna
Terminal
(Sub) (1)
(3)(2)
(4)
I00402
I00403N21548
I00407
Ground point:
Antenna Cord
Center Brace
Pillar (RH)
Pillar (LH) Choke Coil
± BODY ELECTRICALAUDIO SYSTEM
BE±89
2309 Author: Date:
5. Glass printed antenna:
GROUNDING FOR THE ANTENNA CORD AND CHOKE
COIL
HINT:
During troubleshooting, in case that the antenna code continu-
ity check, grounding check and grounding check of the choke
coil are needed, please check refering to the following illustra-
tion.
Terminal connectionNormal condition
(1) e (2)Continuity
(3) e (4)Continuity

I00400
PlugAntenna
Terminal
(1) (2)
I00427
I00428
I00429I00408
Ground point:
Antenna Cord
Center Brace Luggage Room (RH side)
Pillar (LH) Noise Filter BE±90
± BODY ELECTRICALAUDIO SYSTEM
2310 Author: Date:
6. Fixed mast antenna:
GROUNDING FOR THE ANTENNA CORD AND CHOKE
COIL
HINT:
During troubleshooting, in case that the antenna code continu-
ity check, grounding check and grounding check of the choke
coil are needed, please check refering to the following illustra-
tions.
Terminal connectionNormal condition
(1) e (2)Continuity

I03352
5
RadioEITHER AM OR FM DOES NOT WORK, RECEPTION
POOR (VOLUME FAINT), FEWER STATION PRESETS
V08242

Radio±Tape Player Unit (Built±in Power Amplifier)
Problem with radio wave signals or location?
Are both AM or FM defective?
Is power for the antenna being output from the radio assembly?
Go to No.15
Does tape player operate normally?
Temporarily install another speaker. Functions OK?
Radio assembly faulty.Poor signals, poor location.
Radio assembly faulty.
Radio assembly faulty.
Speaker faulty.

Radio±Tape Player Unit (Separate Power Amplifier)

Radio±Tape Player±CD Player Unit (Separate Power Amplifier)
Problem with radio wave signals or location?
Are both AM and FM defective?
Is power for the antenna being output from the radio assembly?
Go to No.15
Temporarily install another speaker. Functions OK?
Hiss noise from speaker?Poor signals, poor location.
Radio assembly faulty.
Radio assembly faulty.
Speaker faulty.
Power amplifier faulty.
Recheck system after repair.
Radio assembly faulty. Recheck system after repair.Ye s NoYe s Ye s Ye s Ye sYe s Ye s Ye s Ye s Ye sYe s
No
No No No No No NoNo No No
Does tape player operate normally?
Radio±CD Player Unit (Built±in Power Amplifier)

Radio±CD Player Unit (Separate Power Amplifier)
± BODY ELECTRICALAUDIO SYSTEM
BE±97
2317 Author: Date:

I01472
Is the condition bad in comparison with other vehicle?
6 Radio POOR RECEPTION
An electric wave environment.
Is there any additional installation parts? (Sun shade film,
telephone antenna etc.).Does the condition get better if removing them? Ye s
No
Ye s
No
Check if there is any scratch and breaking in a
wire on the glass antenna and the defogger pattern.
(See page
BE±115)Influence of additional installation parts. No
Repair Ye s
No
No
Is the contact of the plug jack of the radio OK?
Check for contact.
Ye s
No
Does the condition get better by using the outer
antenna? (Such as pillar antenna)Check the radio.
Ye s
No
Ye s
No Is the contact of the antenna terminal on the glass
surface and the defogger terminal?Measure for contact.
Is the continuity of the antenna cord OK? Exchange the antenna cord.
Check the grounding of the antenna, antenna cord,
choke coil and noise filter.Ye s
NG
Grounding failure.
OK
Does the condition get better by exchanging the choke
coil?Exchange the choke coil. Ye s
No
Ye s
Does the condition get better by exchanging the
antenna cord?Exchange the antenna cord.
Exchange the glass.NoYe s
BE±98
± BODY ELECTRICALAUDIO SYSTEM
2318 Author: Date:

I01473
23 Noise NOISE OCCURS
Does the noise occur only in the radio? It occurs in the cassette CD. (Go to step 13 or 20)
Does the noise occur in a particular place? An electric environment.No
Ye s
Ye s
Is there any additional installation part around the glass
printed antenna? (Sunshade film, telephone antenna, etc.)Does the noise stop by removing it?
Influence of the film of the noise radiation of
additional installation part.
Does the noise occur even pulling out the antenna cord
from the radio?
Check the radio. No
No
NoNo Ye s
Ye s
Ye s
Does the noise occur even pulling out the antenna
terminal on the glass surface?Mixing into the antenna cable.
Is there any adhesive stuck on the bases of the
antenna terminal, defogger terminal and bus bar?Failure of glass installation. Must plane the butyl rubber.
Does the noise occur even pulling out the defogger
terminal?Interfering noise from the defogger line and choke
coil. Does the condition get better by exchanging the
choke coil? Ye s
Ye s
Ye s No
No
No
Check the grounding of the antenna, antenna cord,
choke coil and noise filter.Exchange the choke coil.
NG
Grounding failure.
Does the condition get better by exchanging the antenna
cord?
Radiates directly to the antenna from the generation
source.Exchange the antenna cord.
NoYe s OK
± BODY ELECTRICALAUDIO SYSTEM
BE±111
2331 Author: Date: