MITSUBISHI ENDEAVOR 2004 Service Repair Manual

3. Locality conditions (valley, mountain, etc.)
4. Name and frequency of stations affected by noise
Q: What type of noise is detected, vehicle noise or external noise?
Vehicle noise : It may not be possible to prevent noise if the signal is
weak. Go to step 2.
External noise : In almost all cases, prevention on the receiver side is
next to impossible when the signal is weak. Go to Step 4 .
STEP 2. Ask the driver about the location where the noise occurs
Q: Does the noise occur when entering or near a particular structure
(building, tunnel, mountain, etc.)?
YES: Go to Step 3.
NO: Go to Step 4 .
STEP 3. Check if the noise can be eliminated by adjusting the radio.
1. Adjust the radio as follows.
2. Change to a different station with a stronger signal. This will boost the
systems resistance to outside interference.
3. Suppress high tones to reduce noise.
Q: Has the noise been eliminated?
YES: The noise has now been eliminated. Inform the customer that it is
normal to hear noise while receiving a weak station.
NO: Go to Step 4.
STEP 4. Check for the noise.
Q: Does noise still exist?
YES: If there is still more noise than on other similar radio's find out the
type of noise. Ask the owner for the name and frequency of the affected
stations, and consult with the radio manufacturer service center.
NO
: System is o
peratin
g normall
y.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

INSPECTION PROCEDURE 9: Noise is Present while Moving (FM)
.
DIAGNOSIS 1. The signal becomes weak as the distance from the station's transmission
antenna increases. The signal strength received depends on the signal strength
of the transmitting station and intervening obstructions such as buildings and
hills. Generally speaking, the area of good reception is approximately 20 - 25
km (12 - 16 miles) for stereo reception, and 30 - 40 km (19 - 25 miles) for
monaural reception.
Fi
g. 136: Identif
ying Ins
pection Procedure (Noise Is Present While Movin
g
(Fm)) 1 Of 2

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. The signal will becomes weak when an area of shadow from the transmitting
antenna (places
where there are obst
ruct
ions suc
h as m
ountains or buildings
NOTE: FM waves have the same properties as light, and can be
deflected and blocked. FM signal reception is severely
degraded in the shadow of obstructions such as buildings
or mountains. An FM receiver will then only receive a
reflected signal.
2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

between the station transmitter and the vehicle), and noise will appear. < This
is called first fading, and gives a steady buzzing noise. >
3. If a direct signal hits the antenna at the same time as a signal reflected by
obstructions such as mountains or buildings, interference of the two signals
will generate noise. When moving, noise will appear each time the vehicle's
antenna passes through this kind of obstructed area. The strength and interval
of the noise varies according to the signal strength and the conditions of
deflection. < This is called multipath noise, and is a repetitive buzzing. >
Fig. 137: Identif
ying Ins
pection Procedure (Noise Is Present While Movin
g
(Fm)) 2 Of 2

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. Since FM stereo transmission and reception has a weaker field than monaural,
it is often accompanied by a hissing noise.
After taking measures to prevent the noise, check that no noise occurs.
5. Change to a different station with a stronger wave to boost resistance to
interference.
6. Su
ppress hi
gh tones to reduce noise.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

7. Does vehicle have an antenna which extend? If not eliminate this step.
If there is noise, the following causes can be considered.
8. If due to vehicle noise: It may not be possible to prevent noise if the signal is
weak.
9. If due to external noise: In almost all cases, prevention on the receiver side is
not possible. Weak signals especially are susceptible to interference.
If there is more noise than on radios in other vehicles, find out the noise condition
and the name and frequency of the receiving stations from the owner, and consult
with the radio manufacturer's service center. INSPECTION PROCEDURE 10: Sound mixed with Noise, Only at Night (AM). The following can be considered as possible causes of noise appearing only at
night.
1. It is significantly easier to receive long-distance signals at night. This means
that even stations that are received without a problem during the day may
experience problems at night. Remember that the weaker station is more
susceptible to interference. The appearance of a beat sound may occur in the
evening. A beat sound is created when two signals close in frequency interfere
with each other. A common sign of this type of interference is a repetitious
high-pitched sound that may over power the desired radio station. This sound is
generated not only by sound signals but electrical waves as well.
2. The changing system may also be a source of noise. When diagnosing radio
noise, do not over look the possibility of a problem with the vehicles generator. DIAGNOSIS
STEP 1. Check the vehicles lighting system.
Q: Does the noise disappear when the vehicles headlights are turned
"OFF"?
YES: Go to Ste
p 2.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

NO: Go to Step 3 .
STEP 2. Check that the following actions disappear the noise.
Tune to a station with a stronger signal.
Q: Is there more noise than on radio in other vehicles?
YES: Consult the radio manufacturer's service center.
NO: Check that there is no noise.
STEP 3. Check that the noise fades away when the vehicle harness is
moved away from the radio (if the harness is not in the proper position).
Q: Does the noise fade away when the vehicle harness is moved any from
the radio (If the harness is not in the proper position)?
YES: Consult the radio manufacturer's service center.
NO: If there is more noise than other radios, consult the radio
manufacturer's service center.
INSPECTION PROCEDURE 11: Noise is Overpowering both AM and FM. DIAGNOSIS
STEP 1. Check the state of the antenna.
Q: Is the mast antenna assembled?
YES: Go to Step 2.
NO: Assemble the mast antenna. Check to see that the noise is gone.
STEP 2. Verify that the noise occur when the engine is stopped or the
engine is running.
Q: Does noise occur when the engine is stopped or the engine is running?
When the engine is stopped : Go to Step 3.
When the engine is running :Check the vehicle's noise su
ppressor.
(Refer to

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

INSPECTION PROCEDURE 13: Noise is Detected with Engine Running.
).
STEP 3. Verify that the following actions disappear the noise.
1. Tune to a station with a stronger wave.
2. Extend the antenna completely (Mast antenna).
3. Adjust the sound quality to suppress high tones.
Q: Is the noise eliminated?
YES: Consult the radio manufacturer's service center.
NO: Go to Step 4.
STEP 4. Verify that the radio is correctly grounded
The radio is connected to the ground with an assembling screw.
Q: Is the radio correctly grounded?
YES: Go to Step 5.
NO: Consult the radio manufacturer's service center.
STEP 5. Check the connection of the antenna plug and radio and CD
player.
Q: Is the antenna plug thoroughly connected to the radio and CD player?
YES: Go to Step 7 .
NO: Go to Step 6.
STEP 6. Verify that the noise is eliminated when the antenna plug is
properly attached.
Q: Is the noise eliminated?
YES: Consult the radio manufacturer's service center.
NO: Go to Step 7.
STEP 7. Verify that the antenna is in good condition and is it properly

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

mounted
.
Q: Is the antenna in good condition and is it properly mounted?
YES: Consult the radio manufacturer's service center.
NO: Either repair or replace the antenna assembly. Check to see that the
noise is gone.
INSPECTION PROCEDURE 12: Excessive Noise on AM and FM. DIAGNOSIS Radio reception can be affected by Radio Frequency (RF) emissions from a variety
of sources. The disturbance is even greater if the station is weak or poorly tuned.
FM reception is not as sensitive to disturbances as AM. AM reception is sensitive to
electrical disturbances such as power lines, lightening and other types of similar
electrical phenomena.
STEP 1. Check if the customer heard the noise under any of the following
conditions.
A motorcycle was passing. Lighting was flashing. Passed beneath a power line. Passed beneath a telephone line. Passed by a signal generator. Passed by any other sources of electrical noise. Passed under a bridge or through a tunnel.
Q: Did the noise occur during any of the circumstances listed above?
YES: The observed noise is normal.
NO: Go to Step 2.
STEP 2. Compare the customers radio to another identical model.
Operate the radio in a vehicle with a known good audio system of the same
t
ype as the customer's.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

Q: Is there more noise on the customers radio?
YES: Check all power and ground connections. If all connections are in
good condition, consult the radio manufacturers service center.
NO: The observed noise is normal.
INSPECTION PROCEDURE 13: Noise is Detected with Engine Running. DIAGNOSIS
CAUTION:
Never connect a noise filter to the high tension
cable (spark plug wire). Spark plug wires
incorporate resistors which have the effect of
suppressing noise. If a spark plug wire is found
to be causing noise, it must be replaced. Confirm that the noise is not from an external
source. Noise prevention should be performed by
suppressing strong sources of noise first.
NOTE: Voltage surges can be induced in the electrical system by
the collapse of a field (i.e. When power is removed from the
coil in an A/C compressor clutch). This induced voltage
surge will radiate a Radio Frequency (RF) signal that is
picked up by the audio unit. In the case of the compressor
clutch a "pop" will be heard through the speakers. The
capacitor, installed on this vehicle, will store the excess
voltage and prevent the production of RF noise. This is
because the capacitor will charge and discharge as the
voltage fluctuates. This has the effect of "attracting" noise
and bleeding it to ground without interfering with the
normal flow of current through the system.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

Fig. 138: Diagnostic Procedure Chart

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor

Fig. 139: Identifying Ground Cable

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Radio With Tape Player & Cd Player - Endeavor