RADIO WITH CD PLAYER
TSB Revision
CHASSIS ELECTRICAL
54A-199
INSPECTION PROCEDURE 15: Noise is Present While Moving (FM).
DIAGNOSIS
STEP 1. Check the radio after adjusting it.
Q: Readjust the radio. Is the noise eliminated?
YES : Check that there is no noise.
NO : Go to Step 2.
STEP 2. Check with several broad casting.
NOTE: Multipath noise and fading noise: Because of the fre-
quency of FM waves in extremely high, it is highly susceptible
to effects from geological formations and buildings. These
effects disrupt the broadcast signal and obstruct reception in
several ways.
.
•
Multipath noise
This describes the echo that occurs when the broadcast
signal is reflected by a large obstruction and enters the
receiver with a slight time delay relative to the direct signal
(repetitious buzzing).
•
Fading noise
This is a buzzing noise that occurs when the broadcast sig-
nal is disrupted by obstructing objects and the signal
strength fluctuates intricately within a narrow range.
Q: Is the problem station or location specific?
YES : The effect of an electrical field condition (multipath
noise, fading noise) could be the cause. Check that
there is not noise.
NO : Go to Step 3.
STEP 3. Check that noise appears when the radio switch is
turned on while the vehicle is stopped.
NOTE: Body static electricity from the shock absorber rubber
bushings used to prevent vibration, tires, etc. occurs because
of separation from the ground, causing a buzzing noise. There
is no measures to discharge the static electricity of the vehicle
body. Check that there is no noise.
Q: Does noise appear when the radio switch is turned on
while the vehicle is stopped and the radio is tapped
while tuned away from a station?
YES : Go to Step 4.
NO : It may be static electricity noise.
STEP 4. Verify that the radio is correctly grounded.
Q: Is the radio correctly grounded?
YES : Go to Step 5.
NO : Check that there is no noise.