1992 MITSUBISHI 3000GT ECU

Downloaded from www.Manualslib.com manuals search engine With voltmeterData link connector
’‘:’ ’ ’- Data linkGround ETA,CS 21~33300002230
54-80CHASSIS ELECTRICAL - Lighting System
INPUT SIGNAL

When using the scan tool (MUT) or voltmeter
Using the scan tool or voltmeter, check whether or not the
input signals from each switch are being input to the ETACS
unit.
(1) Connect the scan tool to the data link connector located
at the right side of the junction block or connect the voltme-
ter between the ETACS terminal and the ground terminal.
(2) Check if the buzzer of the scan tool sounds or the needleof the voltmeter moves when each switch is operated.
If the buzzer sounds or the needle moves, the input signalsare being input to the ETACS unit, so that switch can
be considered to be functioning normally. If not, the switch
or switch input circuit is faulty. Check the switch and the
switch input circuit.
When using the MUT-II
cup to 1993 models>
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When using the scan tool (MUT-II)
(1) Connect the scan tool to the data link connector. When
connecting the scan tool to a vehicle up to 1993 models,
use the adapter harness supplied together.
Caution
Turn off the ignition switch beforehand whenever thescan tool is connected or disconnected.
(2) If the scan tool makes a peep sound when each switchis operation (turned ON/OFF), the input signal to ECU
is normally sent from the switch circuit system.
When using the voltmeter
(1)Connect a voltmeter to the ETACS terminal and the ground
terminal of the data link connector using the special tool.
(2) If the voltmeter pointer deflects once when each switchis operated (turned ON/OFF), the input signal to ECU
is normally sent from the switch circuit system.
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Downloaded from www.Manualslib.com manuals search engine 54-I 62CHASSIS ELECTRICAL - Radio and Tape Player
A-4
Broadcasts can be heard but both AM and FM have a lot of noise.
(1)Noise occurs when the engine is stopped.
YesJ
(2)Noise occurs when the engine in running.
Do the following measures eliminate the noise?
@ Tune to a station with a strong signal.
l Extend the antenna completely. (Whip antenna)
l Adjust the sound quality to suppress high tones.
NoIs the radio body ground mounted securely?
Yes
Securely tighten the nuts for the bodyground.
Yes
YesClean the antenna plug and ground
wire mounting area. Mount the anten-
na securely. On a vehicle with a motor
antenna, check the antenna itself. (Re-fer to E-1, 2.)
If there is more noise than other radios, consult a servicecenter
NOTE
About noise encountered during FM reception only.
Due to differences in FM and AM systems, FM is
noise interference (first fading and multipath). (Refer
to A-2.)
not as susceptible as AM to interference from en-
gines, power lines, lightning, etc. On the other hand,
problem with the radio.>waves of noise or distortion generated by typical
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Downloaded from www.Manualslib.com manuals search engine 54-166CHASSlS ELECTRICAL - Radio and Tape Player
IA-7Some noise appears when there is vibration or shocks during traveling.
‘d ~
Are connectors properly connected?
YesNo
---+ Ensure proper connection
t
Does noise appear when the radio switch is turned on while theNovehicle is stopped and the radio is struck while tuned away fromLa station?
YesStatic electricity noise:
Body static electric from the shock absorber rubber bushings used
to prevent vibration, tires, etc. occurs because of separation fromthe ground, causing a buzzing noise.
Since no measures can be taken on the radio side, steps shouldbe taken to discharge the static electricitv of the vehicle bodv.
tIs the radio correctly grounded?
(Is the mounting screw tightened securely?)
1 Yes
tIs the antenna correctly grounded? (If noise appears when the Nocantenna is moved, this means the ground is not securely con-
nected.)
If rust is present on the antenna ground screw, clean and tightenthe ground securely.
Yes
1 Reoair or reolace radio.1
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Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Radio and Tape Player54-167
A-8Noise sometimes appears on FM during traveling.
NoIs the antenna completely extended?
Yes
t Check the antenna itself.
(Refer to E-l, 2.)
+Does the problem clear up whenre
1 No
Yes
iDoes the problem appear only in certain locations and only with yes
certain stations?
No
~ Due to electrical field conditions. (Multipath
noise*, fading noise*).
Are connectors property connected?
Yes
Check connector connections.1
tDoes noise appear when the radio switch is turned on while the
vehicle is stopped
and the radio is struck while tuned away froma station?
Yes
No*Static electricity noise:Sody static electric from the shock absorberrubber bushings used to prevent vibration, tires,etc. occurs because of separation from the
ground, causing a buzzing noise.
Since no measures can be taken on the radioside, steps should be taken to discharge the
static
electricitv of the vehicle bodv.
Is the radio body correctly grounded?
No(Is the mounting screw tightened securely?
)
Yes
-) Tighten the screw securely.I
Is the antenna correctly grounded? (If noise appears when the antennais moved, this means the ground is not securely connected.)
Yes
If rust is present on the antenna ground screw,clean and tighten the ground securely.
*
1 Repair or replace radio.1
About multipath noise and fading noise
Because the frequency of FM waves is extreme-
ly high, it is highly susceptible to effects from
geological formations and buildings. These ef-
fects disrupt the broadcast signal and obstruct
‘reception in several ways.l Multipath noise
This describes the echo that occurs when the
broadcast signal is reflected by a large obstruc-
tion and enters the receiver with a slight time
delay relative to the direct signal (repetitious
buzzing).l Fading noise
This is a buzzing noise that occurs when the
broadcast beam is disrupted by obstructing ob-
jects and the signal strength fluctuates intricately
within a narrow range.
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Downloaded from www.Manualslib.com manuals search engine 54-168CHASSIS ELECTRICAL - Radio and Tape Player
IA-9Ever-present noise.I
Noise is often created by the following factors, and
often the radio is OK when it is checked individually.l Traveling conditions of the vehicle
l Terrain of area traveled through
l Surrounding buildings
l Signal conditions
l Time periodFor this reason, if there are still problems with noiseeven after the measures described in steps A-l
to A-8 have been taken, get information on the fac-
tors listed above as well as determining whetherthe problem occurs with AM or FM, the station
names, frequencies, etc., and contact a service cen-
ter.B. RADIO
IB-lNo power is supplied when the switch is set to ON.IIIIs multi-purpose fuse No. 4 blown or is the circuit open?Replace fuse or repair harness.
NoIs the connector at the back of the radio connected properly?
Yes
Connect connector securely.1t
NoDisconnect and check the connector at the rear of the radio. Is the ACC / Repair harness.
power (12 V) being supplied to the radio?J
I
Yes
1 Reoair or reolace radio.
1 B-2No sound from one speaker.ICheck to see if there is any sound when attached
to another radio.
I-=----[Repair or replace radio unit.
No
checkthespeakerharnessfor conductance.
out.*Speakarj
NoRepair speaker harness and ensure
proper connection of relay connectors.
tRepair or replace speaker.
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Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Radio and Tape Player54-I 71
1 B-5Distortion on AM or on both AM and FM.Are the speaker cords in contact with the cone paper?
NoRemove cords away from cone
pa-per.Remove the speakers and check for tom cone paper or foreign objects.
INoRepair or replace speakers.
iCheck for deformation with speaker installed.
No
Yes- Install speaker securely.
\ Repair or replace radio.j
B-6Distortion on FM onlyDoes the distortion persist when the radio is tuned to another
Nostation?
Yes
)- Due to weak electrical field of radiostation
YesDoes distortion increase or decrease when the vehicle is moved? ,
/ NoDue to multipath noise
1
1Repair or replace radio.
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Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Radio and Tape Player54-179/
L
D-2No sound.1I
Does it play if an existing proper CD is inserted? )Yes-Replace defective CD.
No
No
FYes
ture, and recheck operation.*IDoes it operate properly?
II NoAre the radio set and CD player connected
C;_TRepair or replace CD player.
-(The combined radio cassette must operate
properly.)
D-3CD sound skips.
1.Sound sometimes skips during parking.
iIs CD face scratched or dirty?CD is defective, or clean CD.
NoDoes it play properly if CD is replaced with an existing proper CD?
Yes
Repair or replace CD player..
1 Replace CD.
2.Sound sometimes skips during driving.(Stop vehicle, and check it.)
(Check it by using a proper CD which is free of scratch, dirt or other abnormality.)
Does sound skip when the side of
YesNo
tSecurely mount the CD player.
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Downloaded from www.Manualslib.com manuals search engine CHASSIS ELECTRICAL - Radio and Taste Plaver
D-4Sound quality is poor.1Does it play properly if another proper CD is loaded?
No
Replace CD.Repair or replace CD player.
1 D-5CD will not be ejected.Is the key switch (ignition key) at ACC or ON?
YesTurn the key to ON.
tIs the combined amplifier or radio set connected securely?
YesSecurely connect the subjected one.
If CD is not ejected, don’t reject it.
The player may be damaged. Therefore, contact a service
shop for reoairs.
D-6No sound from one speaker.Is CD player securely connected to the combined radio set?
YesSecurely connect them.
Does it play properly if another CD player is combined?
NoRepair or replace CD player.
IRepair or replace the combined radio set.
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