Service Manuals, User Guides, Schematic Diagrams or docs for : . Car Manuals Toyota 4Runner 1996-2003 Approved SIL techinfo.toyota.com ileaf 02toyrm 02toypdf 02rmsour 2002 024runne be audsy descri
<< Back | HomeMost service manuals and schematics are PDF files, so You will need Adobre Acrobat Reader to view : Acrobat Download Some of the files are DjVu format. Readers and resources available here : DjVu Resources
For the compressed files, most common are zip and rar. Please, extract files with Your favorite compression software ( WinZip, WinRAR ... ) before viewing. If a document has multiple parts, You should download all, before extracting.
Good luck. Repair on Your own risk. Make sure You know what You are doing.
Image preview - the first page of the document
>> Download descri documenatation <<
Text preview - extract from the document
BE-1 19
BODY ELECTRICAL - AUDIO SYSTEM
AUDIO SYSTEM BE243-01
DESCRIPTION
1. RADIO WAVE BAND
The radio wave bands used in radio broadcasting are as follows:
Frequency 30 kHz 300 kHz 3 MHz 30 MHz 300 MHz
Designation LF MF HF VHF
AM FM
Radio wave
Modulation Amplitude modulation Frequency modulation
LF: Low Frequency
MF: Medium Frequency
HF: High Frequency
VHF: Very High Frequency
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 can be received in very clearly.
Not only does FM stereo have the smallest service area, but it
FM (Stereo) also picks up static and other types of interference ("noise")
FM (Monaural) easily.
AM
BE2818
3. RECEPTION PROBLEMS
Besides the problem of static, there are also the problems
called "fading", "multipath" and "fade out". These problems are
caused not by electrical noise but by the nature of the radio
waves themselves.
Fading (1) Fading:
lonosphere
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 "fading".
BE2819
2002 4RUNNER (RM887U)
Author : Date : 1587
BE-120
BODY ELECTRICAL - AUDIO SYSTEM
(2) Multipath:
Multipath
One type of interference caused by the bounce of
radio waves off of obstructions is called "multipath".
Multipath occurs when a signal from the broadcast
transmitter antenna bounces off buildings and
mountains and interferes with the signal that is re-
ceived directly.
BE2820
(3) Fade Out:
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 obstruction. This is called "fade out".
BE2821
4. COMPACT DISC PLAYER
Compact Disc Players use a laser beam pick-up to read the dig-
ital signals recorded on the CD and reproduce analog signals
of the music, etc.
HINT:
Never attempt to disassemble or oil any part of the player unit.
Do not insert any object other than a disc into the magazine.
NOTICE:
CD players use an invisible laser beam which could cause
hazardous radiation exposure. Be sure to operate the play-
er correctly as instructed.
5. Tape player/head cleaning:
Example
MAINTENANCE
Head Capstan
(a) Raise the cassette door with your finger.
Next, using a pencil or similar object, push in the guide.
(b) Using a cleaning pen or cotton applicator soaked in clean-
er, clean the head surface, pinch rollers and capstans.
Pinch Roller N17398
2002 4RUNNER (RM887U)
Author : Date : 1588
BE-121
BODY ELECTRICAL - AUDIO SYSTEM
6. CD player/disc cleaning:
MAINTENANCE
If the disc gets dirty, clean the disc by wiping the surface from
the center to outside in the radial directions with a soft cloth.
NOTICE:
Do not use a conventional record cleaner or anti-static pre-
servative.
BE4331
7. OUTLINE OF AVC-LAN
(a) What is AVC-LAN?
AVC-LAN is the abbreviation, which stands for Audio Visual Communication-Local Area Network.
This is a unified standard co-developed by 6 audio manufactures associated with Toyota Motor Corpo-
ration.
The Unified standard covers signals, such as audio signal, visual signal, signal for switch indication
and communication signal.
(b) Objectives
Recently the car audio system has been rapidly developed and functions have been changed drasti-
cally. The conventional system has been switched to the multi-media type such as a navigation sys-
tem. At the same time the level of customers needs to audio system has been upgraded. This lies be-
hind this standardization.
The concrete objectives are explained below.
(1) When products by different manufactures were combined together, there used to be a case that
malfunction occurred such as sound did not come out. This problem has been resolved by stan-
dardization of signals.
(2) Various types of after market products have been able to add or replace freely.
(3) Because of the above (2), each manufacture has become able to concentrate on developing
products in their strongest field. This has enabled many types of products provided inexpensive-
ly.
(4) Conventionally, a new product developed by a manufacture could not be used due to a lack of
compatibility with other manufactures products. Because of this new standard, users can enjoy
compatible products provided for them timely.
(c) The above descriptions are the objectives to introduce AVC-LAN. By this standardization, develop-
ment of new products will no longer cause systematic errors. Thus, this is very effective standard for
a product in the future.
HINT:
S When +B short or GND short is detected in AVC-LAN circuit, communication stops. Accordingly the
audio system does not function normally.
S When audio system is not equipped with a navigation system, audio head unit is the master unit. (When
audio system is equipped with a navigation system, radio receiver is the master unit.)
S The car audio system using AVC-LAN circuit has a diagnosis function.
S Each product has its own specified numbers called physical address. Numbers are also allotted to
each function in one product, which are called logical address.
2002 4RUNNER (RM887U)
Author : Date : 1589
◦ Jabse Service Manual Search 2026 ◦ Jabse Pravopis ◦ onTap.bg ◦ Other service manual resources online : Fixya ◦ eServiceinfo