Mitsubishi 380. Manual — part 920

RADIO WITH CD PLAYER

CHASSIS ELECTRICAL

54A-214

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, tyres, 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.

STEP 5. Check by replacing radio and CD player or radio,
CD player and CD changer.

Q: Do the other radio and CD player or radio, CD player

and CD changer work normally?
YES : Either repair or replace the original radio and CD

player or radio, CD player and CD changer. Check
that there is no noise.

NO : Either repair or replace the antenna assembly. Check

that there is no noise.

INSPECTIONPROCEDURE 14: Constant Noise.

DIAGNOSIS

.

Use the Symptom Chart to diagnose the possible cause(s) of
the noise. Noise is often created by the following factors:

• Travelling conditions of the vehicle

• Terrain of area travelled through

• Surrounding buildings

• Signal conditions

• Time period

If there are still problems with noise, even after performing
inspection procedures 8 to 15, obtain information on the factors
listed above. Determine whether the problem occurs on AM or
FM, the station names, frequencies, etc. and contact the radio
manufacturer's service centre.

RADIO WITH CD PLAYER

CHASSIS ELECTRICAL

54A-215

INSPECTION PROCEDURE 15: No reception (AM).

DIAGNOSIS

.

STEP 1. Check to see if inspections are taking place is an
area exposed to special electric fields.

Q: Are inspections taking place under special electric field

conditions? (underground garage, inside a building,
etc.)?
YES : Go to Step 2.
NO : Go to Step 3.

STEP 2. Move the vehicle and check the radio.
Move the vehicle to a good reception area that is not exposed
to special electric fields.

Q: Is reception of the strongest radio frequency possible

within the area?
YES : There is no action to be taken.
NO : Go to Step 3.

STEP 3. Tune the radio, and then check it.

Q: Did the sensitivity improve after tuning?

YES : There is no action to be taken.
NO : Go to Step 4.

STEP 4. Check the connection of the antenna plug and
radio and CD player or radio, CD player and CD changer.

Q: Is the antenna plug thoroughly connected to the radio

and CD player or radio, CD player and CD changer?
YES : Go to Step 5.
NO : Thoroughly connect the antenna plug and the radio

and CD player or radio, CD player and CD changer.
The radio should sound normally.

STEP 5. Check by replacing radio and CD player or radio,
CD player and CD changer.

Q: Do the other radio and CD player or radio, CD player

and CD changer work normally?
YES : Either repair or replace the original radio and CD

player or radio, CD player and CD changer. The radio
should sound normally.

NO : Either repair or replace the antenna assembly. The

radio should sound normally.

RADIO WITH CD PLAYER

CHASSIS ELECTRICAL

54A-216

INSPECTION PROCEDURE 16: Poor Reception.

DIAGNOSIS

.

STEP 1. Check to see if inspections are taking place is an
area exposed to special electric fields.

Q: Are inspections taking place under special electric field

conditions? (underground garage, inside a building,
etc.)?
YES : Go to Step 2.
NO : Go to Step 3.

STEP 2. Move the vehicle and check the radio.
Move the vehicle to a good reception area that is not exposed
to special electric fields.

Q: Is reception of the strongest radio frequency possible

within the area?
YES : Check that a poor reception is resolved.
NO : Go to Step 3.

RADIO WITH CD PLAYER

CHASSIS ELECTRICAL

54A-217

STEP 3. Tune the radio, and then check it.

Q: Did the sensitivity improve after tuning?

YES : Check that a poor reception is resolved.
NO : Go to Step 4.

STEP 4. Check with several broadcasting stations.

NOTE: Two types of noise are addressed in this procedure,
multipath and fading noise. The frequency of FM waves is
extremely high. This makes them susceptible to effects from
geological formations and buildings. These effects disrupt the
broadcast signal and obstruct reception in many ways.

.

• Multipath noise is 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).

• A fading or buzzing noise may occur when the broadcast

beam is disrupted by obstructing objects and the signal
strength fluctuates within a narrow range.

Q: Is the abnormality in reception generated only within a

certain range?
YES : Check that a poor reception is resolved.
NO : Go to Step 5.

STEP 5. Check the connection of the antenna plug and
radio and CD player or radio, CD player and CD changer.

Q: Is the antenna plug thoroughly connected to the radio

and CD player or radio, CD player and CD changer?
YES : Go to Step 6.
NO : Thoroughly connect the antenna plug and the radio

and CD player or radio, CD player and CD changer.
Check that a poor reception is resolved.

STEP 6. Check by replacing radio and CD player or radio,
CD player and CD changer.

Q: Do the other radio and CD player or radio, CD player

and CD changer work normally?
YES : Either repair or replace the original radio and CD

player or radio, CD player and CD changer. Check
that a poor reception is resolved.

NO : Either repair or replace the antenna assembly. Check

that a poor reception is resolved.