ECU MITSUBISHI 3000GT 1991 Service Manual

BODY - Power Window
Checking the driver door switch circuit (Disconnect the connector of the electronic control unit’and
check the wiring harness side.)
ECU Terminal Connected to/
No.measured partMeasurement ~~~~e~rionCheck conditionsStandard
14”’
16”’
lo**Driver door switch
Passenger door
switch
Driver door switch
and passenger
door switchResistance
Resistance
Resistance14*‘-ground Driver door16*‘-ground Passenger
door1 O*‘-groundDriver doorand/or
passenger
doorClosedNo continuity
OpenContinuity
ClosedNo continuity
OpenContinuity
ClosedNo continuity
Driver door
andpassenger
doorOpenContinuity
NOTE“I : Vehicles without theft-alarm system
“2: Vehicles with theft-alarm system
Check the individual part
Door switch: Refer to
P.42-41.
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BODY - Central Door Locking System42-55
Ground ETACS
,611338Nith voltmeterCENTRAL DOOR LOCKING SYSTEM M42ZDAJ
IGNITION KEY REMINDER TROUBLESHOOTING
GUIDE
INPUT CHECK
Using the multi-use tester or voltmeter, check whether or not
the input signals from each switch are being input to the
ETACS unit.
(1) Connect the multi-use tester to the diagnosis check
connector located at the right side of the junction block or
connect the voltmeter between the ETACS terminal and
the ground terminal.
(2) Check if the buzzer of the multi-use tester sounds or the
needle of the voltmeter moves when each switch noted
below is operated.
If the buzzer sounds or the needle moves,. the input signals
are 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.
l Door lock actuator
l Door switch
l Key reminder switch
IGNITION KEY REMINDER TROUBLESHOOTING QUICK-REFERENCE TABLE
CENTRAL DOOR LOCKING SYSTEM
Problem
No unlock operation can be made by
pressing door lock knob after
fulfil-ment of following conditions.
l Insertion of key in ignition switch
(key reminder switch OFF)
l Opening of door(door switch ON)Probable causeCheck methodRemedy
Key reminder switchIf found defective afterCorrect harness or
input circuit shortedinput check, check circuit
bench test No. 4
rep:a~~~ key reminder
Key reminder
(P.42-59).switch shorted
Door switch inputIf found defective afterCorrect harness or
circuit brokeninput check, check circuit
replace door switch
bench test No. 5
Breaks in door switch
(P.42-60).Faulty electronic
-Replace the electronic
control unitcontrol unit
NOTE“ECU” (Electronic Control Unit) indicates the ETACS unit
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42-56BODY - Central Door Locking System
CHECKING INDIVIDUAL PART AND CIRCUIT (IGNITION KEY REMINDER SYSTEM)
1. ETACS POWER-SUPPLY AND GROUND CIRCUITS
L-
Batterv
$1,\ .
\I \/ \I
‘/1,\/2-“1
m+,2T.,l\ ,.c.i -
151
Junction block (Multi-purpose fuse)
Jumper connector
ETACS unit(ECU)
“I : Vehicles without theft-alarm system
“2: Vehicles with theft-alarm systemz1116FO314Description of operation
The battery supplies a stabilized 5V power supply to the electronic control unit, via the constant-voltage circuit
and terminal (51) directly connected to the battery. If there is an abnormal condition of the power-supply
circuit, other ETACS functions also will not operate.
Electronic control unit terminal voltage (Connection status of electronic control unit connector)
ECU terminal No. Signal
StatusTerminalvoltage
I
51Electronic control unit power supply
At all timesSystem
voltage
IChecking the ground circuit (Disconnect the connector and check the wiring harness side.)
IIII1Terminal No.Connected to/measured part
MeasurementTesterconnectionCheck conditionsStandard57”’
Electronic control unit ground
Resistance57*‘-groundAt all timesContinuity
59”)59*2-ground
NOTE
“I : Vehicles without theft-alarm system.“2: Vehicles with theft-alarm system
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BODY - Central Door Locking System42-57
2. DOOR LOCK ACTUATOR INPUT CIRCUIT
L
ETACS
unit (ECU)
Fusible link @
Junction block
(Multi-purpose fuse)
r7‘?r p O.BBBI
“1 : Vehicles without theft-alarm system
“2: Vehicles with theft-alarm systemU-U16(RI-U16FO316
‘IL/Description of operation
If the door is opened with the ignition key inserted and then locking is made by means of inside lock knob, the
door lock actuator is brought to the OFF position, sending H signal to the electronic control unit.
This signal operates the timer. circuit of the electronic control unit and the driving circuit operates to actuator
all the door lock actuators.
Electronic control unit terminal voltage (Connection status of electronic control unit connector)
ECU terminal No. Signal
ConditionTerminal
voltage
ll”,13”’ (LH)Door lock actuator switchDoor lock actuator switchsignalLock (OFF)5v
12”‘. 14”:’ (RH)Unlock (ON)ov
Door lock actuator switch circuit test (Disconnect the connector of the electronic control unit and
check the wiring harness side.)
ECU TerminalConnected to/No.measured partMeasurementTester
connectionCheck conditionsStandard
Door lock actuator
ll*‘, 13”’ (LH) switch signalResistance11 *‘-groundDoor lockLock (OFF)12*‘-groundactuator switchNo continuity
12”‘. 14”’ (RH)13*:-ground14*‘-groundUnlock (ON) Continuity
NOTE*1 : Vehicles without theft-alarm system
“2: Vehicles with theft-alarm systemChecking the individual part
Door lock actuator: Refer to
P.42-62.
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42-58BODY - Central Door Locking SystemI3. DOOR LOCK POWER RELAY ACTIVATION CIRCUIT
Fusible link 0
“I : Vehicles without theft-alarm system“2: Vehicles with theft-alarm system
Door lockactuator:
(LH)
‘d
Door lockactuator(RH)16FO329’Description of operation
If the door is opened with the ignition key inserted and then door locking is made, transistor Tr of the
electronic control unit is turned ON to operate the door lock power relay (unlock side) and the door lock
actuator is unlocked.
NOTEBefore locking the front seat passenger door, make sure that the driver door lock actuator is in the LOCK
position. If the driver door lock actuator is in the UNLOCK position, the front passenger door lock actuator
does not operate.
Electronic control unit terminal voltage (Connection status of electronic control unit connector)
ECU terminal No. Signal
ConditionTerminalvoltage
1XI, 3”’Door lock power relaySystem(unlock side) signalAt all times (except when door unlock isin operation)voltage
NOTE“I : Vehicles without theft-alarm system
“2: Vehicles with theft-alarm system
Checking the individual part
Door lock power relay: Refer to
P.42-63.
LJ
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BODY - Central Door Locking System
4. KEY REMINDER SWITCH INPUT CIRCUIT42-59

Fusiblelink@
ETACSunit(ECU)
16FO319
Junction block
(Multi-purpose fuse)
Key reminder
switch
ETACSunit(ECU)
16FO318
bDescription of operation
Insert the key in the ignition key cylinder, and the key reminder switch will be turned OFF, sending H signal to
the electronic control unit. Pulling the key out of the cylinder will turn on the key reminder switch, sending L
signal to the electronic control unit.
If there is any abnormality in the key reminder switch input circuit, abnormal key reminder buzzer will result.
Electronic control unit terminal voltage (Connection status of electronic control unit connector)
ECU terminal No. Signal
ConditionTerminal
voltage60”’
Key reminder switch signalKey is pulled outov
64”’
Key is inserted5v
Checking the key reminder switch circuit (Disconnect the connector of the electronic control unit and
check the wiring harness side.)
Terminal No.Connected to/measured partMeasurementTesterconnectionCheck conditronsStandard60”’
Key reminder swatchResistance60*‘-groundKey is pulled outContinuity
Key is insertedNo continuity
NOTE“I : Vehicles without theft-alarm system*2: Vehicles with theft-alarm system
/Checking the individual part
’Key reminder switch: Refer to GROUP 54 - Ignition Switch.
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42-60
BODY - Central Door Locking System
5. DOOR SWITCH INPUT CIRCUIT
ETACSunit(ECU)
*1 : Vehicles without theft-alarm system*2: Vehicles with theft-alarm systemPassen&r door
switchDrivergoorswitch16FO326Description of operation
When the front door is closed (the door switch is switched OFF), HIGH-level signals are sent to the electronic
control unit; when the front door is opened (the door switch is switched ON), LOW-level signals are sent to
the electronic control unit.
Electronic control unit terminal voltage (Connection status of electronic control unit connector)
’d
NOTE
Driver door and passenger doorClosed5v
“1: Vehicles without theft-alarm system
“2: Vehicles with theft-alarm system
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51-26EXTERIOR - Windshield Wiper and Washer
MIST WIPERS/WASHER-INTERLOCKED WIPERS
ProblemProbable cause(s)
Checking procedureRemedy
The wipers do not function when
the washer switch is switched ONDamage or disconnectionIf a malfunction is discov-
of the wiring of the
ered as a result of theRepair the wiring
har-for 0.6 second or longer.
(With the wiper switch at thewasher switch input
circuit.checking of the inputness, or replace the
column switch.
“INT” position, however, inter-
mittent operation of the wipers
is normal, and the washer
function is normal.)
(P.51-241, conduct check
Damage or disconnectionNo.5(P.51-31)oftheindividual part and circuit,
of the wiring of the
washer switch.
Malfunction of the elec-tronic control unit.
-Replace the electronic
control unit.
The wipers do not function whenMalfunction of the elec-
-the washer switch is switched ONtronic control unit.Replace the electronic
for less than 0.6 second.control unit.
(The wipers and washer do func-
tion, however, when the washer
switch is switched ON for 0.6
second or longer.)
NOTE“ECU” (electronic control unit) indicates the ETACS unit.
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EXTERIOR - Windshield Wiper and Washer
CHECKING INDIVIDUAL PART AND CIRCUIT1. IGNITION SWITCH INPUT CIRCUIT51-27
BatteryFusible link
LOCK lgnitlon switch
Junction block
(Multl-purpose fuse)
Jumper connector
i! ~~A$ unit
“I : Vehicles without theft-alarm system
“2: Vehicles with theft-alarm system16FO313
Operation Description
As the condition for operation of the system, HIGH-level signals are sent to the electronic control unit when
the ignition switch is set to the “ACC” or “ON” position.
Electronic Control Unit Terminal Voltage (Disconnect the ECU Connector and Check at the Wiring
Harness Side.)
ECU terminal No.SignalStatusStandard
53Ignition switch (ACC)Ignition switchOFFov
ACCSystem
voltageChecking Individual Part
Ignition switch: Refer to GROUP 54
- Ignition Switch.
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51-28EXTERIOR - Windshield Wiper and Washer
2. WIPER SWITCH
‘ANT” INPUT CIRCUIT
Iin,Ullnl,,en, ll”lC I”,CI”,IIdctcclion CIICUI,
5v
i-i
7 ;;:2
A3II--
ETACS unrt‘,ij I
Wrperswitch
Lolumn switch
” J/B
“I : Vehicles without theft-alarm system“2: Vehicles with theft-alarm system16FO320
Operation Description
L+,When the wiper switch is set to the “INT” position, LOW-level signals are input to the electronic control unit;
the intermittent time interval detection circuit is then activated, and the wipers operate at the intermittent
time interval according to the setting of the intermittent variable volume switch.
Electronic Control Unit Terminal Voltage (Connection Status of Electronic Control Unit Connector)
ECUterminal No.
9”’
1 1 *2
Signal
Wiper switch “INT” signalStatus
Wiper switch “OFF”Wiper switch “INT”
Terminal
voltage
5Vov
Checking the Wiper Switch
(“INT” Position) Circuit (Disconnect the ECU Connector and Check at the
Wiring Harness Side.)
ECUConnected to/measured
terminal No.componentMeasurement TesterconnectionCheck conditionsStandardWiper switch “INT”
No continuityChecking Individual Part
Wiper switch: Refer to
P.51-33.
NOTE
*l : Vehicles without theft-alarm system
“2: Vehicles with theft-alarm system
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