Toyota Sienna Service Manual: Identification of noise source
1. Radio Description
- Radio frequency band
- Radio broadcasts use the radio frequency bands
shown in the table below.
![Radio Description](images/books/424/58/index295.jpg)
- Service area
![Radio Description](images/books/424/58/index296.jpg)
- The service areas of AM and FM broadcasts are
vastly different. Sometimes an AM broadcast
can be received very clearly but an FM stereo
cannot. FM stereo has the smallest service area,
and is prone to pick up static and other types of
interference such as noise.
- Radio reception problems
HINT:
In addition to static, other problems such as
"phasing", "multipath", and "fade out" exist. These
problems are not caused by electrical noise, but by
the radio signal propagation method itself.
![Radio Description](images/books/424/58/index297.jpg)
- Phasing
AM broadcasts are susceptible to electrical
interference and another kind of interference
called phasing. Occurring only at night, phasing
is the interference created when a vehicle
receives 2 radio wave signals from the same
transmitter. One signal is reflected off the
ionosphere and the other signal is received
directly from the transmitter
![Radio Description](images/books/424/58/index298.jpg)
- Multipath
Multipath is a type of interference created when
a vehicle receives 2 radio wave signals from the
same transmitter. One signal is reflected off
buildings or mountains and the other signal is
received directly from the transmitter.
![Radio Description](images/books/424/58/index299.jpg)
- Fade out
Fade out is caused by objects (buildings,
mountains, and other such large obstacles) that
deflect away part of a signal, resulting in a
weaker signal when the object is between the
transmitter and vehicle. High frequency radio
waves, such as FM broadcasts, are easily
deflected by obstructions. Low frequency radio
waves, such as AM broadcasts, are much more
difficult to deflect.
- Noise problem
Technicians must have a clear understanding about
each customer's noise complaint. Use the following
table to diagnose noise problems.
![Radio Description](images/books/424/58/index21.jpg)
HINT:
If the noise does not match the examples above, refer to the
descriptions about phasing and multipath.
1 VEHICLE BROUGHT TO WORKSHOP
2 INSPECT BATTERY VOLTAGE
Standard voltage:
11 to 14 V
If the voltage is below 11 V, recharge or replace the battery
before proceeding.
3 BASIC INSPECTION
Turn ...
HINT:
Before inspecting the suspected areas listed in the table
below, check the fuse and relay.
Before inspecting the suspected areas listed in the table
below, check for DTCs.
...
Other materials:
Removal
NOTICE:
Do not adjust the brake booster push rod.
Do not change the combination of the diameter
converting unit and brake.
1. REMOVE FRONT WHEEL
2. DRAIN BRAKE FLUID
NOTICE:
Wash the brake fluid off immediately if it attaches to
any painted surfaces.
3. SEPARATE BATTERY NEGATIVE TERM ...
Access monitor result
(A) select the following menus on the intelligent tester:
diagnosis, enhanced obdii, monitor info
and monitor result. The monitor status
appears after the component name.
INCMP: The component has not been monitored
yet.
PASS: The component is functioning normally.
FAIL: The component is ...
Installation
1. INSTALL VENTILATION VALVE
(a) Install the ventilation valve.
(1) Apply adhesive to 2 or 3 threads.
Adhesive:
Part No. 08833-00070, Three Bond 1324 or
equivalent
(2) Install the ventilation valve.
Torque: 27 N*m (275 kgf*cm, 20 ft.*lbf)
2. CONNECT VENTILATION HOSE
(a) Connect ...