1991 MITSUBISHI 3000GT relay

13-124FUEL SYSTEM -On-vehicle Inspection of MPI Components
INSPECTIONUsing Multi-use tester
Function
Actuator testItem No.Drive content
Check conditionNormal state
09Turn solenoid valve fromIgnition switch: ONOFF to ONr%;reard when
HARNESS INSPECTION
@ Harness side
connector
Measure the power supply voltage.
l Connector: Disconnectedl Ignition switch: ON
Voltage
(V)2-* q
SVRepair thei* harness.(@m - Con-
trol relay)
7FUO527
Check for an open-circuit, or a short-circuit to ground, between the fuelpressure control solenoid valve andthe engine control unit.
lEngine controLunit connector:
Disconnected
lFuel pressure control valve con-nector: Disconnected
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13-126FUEL SYSTEM - On-vehicle Inspection of MPI Components
WASTE GATE CONTROL SOLENOID VALVE

7FU1007Control relav
Waste gate control
solenoid valve
Q Equipment side
connector
unit
0110324Enqlne control unit connector
7FUO653
OPERATIONlThe waste gate control solenoid valve is an ON-OFF type solenoid valve that controls the boost pressure
that is introduced to the waste gate actuator.
lBattery power is supplied to this valve via the control relay. When the engine control unit turns ON the
internal power transistor, the coil is energized to release part of the boost pressure applied to the waste
gate actuator.
TROUBLESHOOTING HINTSIf the waste gate control solenoid valve harness and the unit itself are normal, but poor acceleration or other
abnormalities are experienced, the
follwing problems are suspected.
(1) Faulty boost pressure control system
(2) Poor connection of intake air hose
(3) Faulty turbocharger or waste gate actuator
(4) Clogged exhaust system
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FUEL SYSTEM - On-vehicle Inspection of MPI Components'13-127
INSPECTIONUsing Multi-use tester
LFunctionItem No.Drive contentCheck conditionNormal state
Actuator test12
Turn solenoid valve fromIgnition switch: ONOFF to ON
CliZli~,“eard when
HARNESS INSPECTION
Measure the power supply voltage.
l Connector: Disconnectedl Ignition switch: ON
trol relay)
7FUO525
Check for an open-circuit, or a short-circuit to ground, between the wastegate control solenoid valve and the
engine control unit.
lWaste gate control solenoid valveconnector: DisconnectedlEngine control unit connector:
DisconnectedRepair the
-+ harness.
(@m- ml)
7FUO526
ACTUATOR INSPECTIONRefer to GROUP 15.
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FUEL SYSTEM - On-vehicle Inspection of MPI Components
ANTI-LOCK BRAKE SIGNAL
Engine control
unit connectorABS ECU@ ABS control unit
equipment side connector
A28
tABS HU
Engine
control
unit
114
/L6FU1542
7FUO653,
OPERATIONlThe anti-lock brake signal is input to the engine control unit from the anti-lock brake system
(ABS) control
unit as a signal to indicate whether or not the motor relay is activated. Based on this signal, the engine
control unit controls the idle-speed control servo to secure effective anti-lock braking.
lWhen the motor relay is activated, the ABS control unit turns ON the power transistor, short-circuiting the
terminal to ground. This causes the anti-lock brake signal to go from high to low.
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CRUISE CONTROL SYSTEM - Troubleshooting13-163CHECK CHART
it l/Inspection of control unit power supply circuit
L;
,/
id
CRUISE#fi$ROL
0
SWITCH
“71
TROUBLESHOOTING HINTSECU terminal voltage
DESCRIPTION OF OPERATIONThe power is supplied through the ignition switch
(IG,) and cruise control main switch to the control
unit.
1. When the cruise control main switch is set to
ON with the ignition switch at ON, the current
from switch
S, flows through relay Ry, in the
switch. Accordingly, the contact of relay
Ry, is
closed and the power is supplied to the control
unit.
2. When the main switch is released, it automati-
cally returns to the neutral position. Since the
current from switch
S2 flows to relay Ry,, the
contact of relay Ry, remains closed.
3.When the main switch is set to OFF, current to
relay
Ry, is interrupted. This opens the contact
of relay
Ry, to stop the power supply to the
control unit. When the switch is released, it
automatically returns to the neutral position, but
relay Ry, stays in the OFF state.
4. When the ignition switch is set to OFF while
relay Ry, in the main switch is ON, relay
Ry, is
forced to the OFF state just like when the main
switch is set to OFF. Even if the ignition switch
is set to ON again, relay
Ry, stays in the OFF
state until the main switch is set to ON.
NOTEThe numbers beside each connector correspond
to those in the section
(P.13-176) “HARNESS
AND COMPONENTS LAYOUT”
TerminalNo.Signal nameCondition
I
TerminalvoltageI
2Control unit power supplyMain switch ON and neutral positionSystem voltage
thereafter
Main switch OFF and neutral positionov
thereafter8, 14
Control unit groundAt all timesov
16Control unit back up power supplyAt all timesSystem voltage
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COOLING - Specifications / Troubleshooting
SEALANT AND ADHESIVE14-3
MMCE- -
/
id
ItemsSpecified sealants and adhesive/
Engine coolant temperature gauge unit
Engine coolant temperature sensor (Engine control)
Engine coolant temperature sensor (Air conditioner)3M Nut Locking Part No. 4171
TROUBLESHOOTING
L
MllEAAL
Symptom
OverheatProbable cause
Insufficient engine coolant
Too high an anti-freeze concentration
Inoperative electric cooling fan
Faulty thermosensor
Faulty electrical motor
Faulty radiator fan relayRemedy
Replenish
Correct anti-freeze concentration
Replace
Damaged or blocked (insufficiently ventilated)
radiator finsCorrect
Water leaks
Damaged radiator core joint
Corroded or cracked hoses
(radiator hose, heater hose, etc.)
Faulty cap valve or setting of spring
Cracked thermostat housing
Loose water pump mounting bolt or leaking
gasket
Replace
Loose bolt or leaking gasket in water outlet
I
Correct or replacefitting
Loose bolt or leaking gasket in water inletfitting
Loose thermostat housing bolts or leakingfrom gasket
Retorque bolts or replace gasket
Faulty automatic transaxle oil cooler operation
Blocked or collapsed hose and pipeReplace
Loose hose and pipe connectionCorrect
Faulty thermostat operationReplace
Faulty water pump operationReplace
Water passage clogged with slime or rust depositClean
or foreign substance
No rise in temperature
Faulty thermostatReplace
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COOLING - Troubleshootina14-5
i
L
@2L-R
:---I
I
I
I
I
III1 nI
I
1 6IIIII
I
I
I
I
I
I
I
I
ii
II
! cI1
I--@
G-B
FUSIBLELINK@
_------ __._ -_--
L-
AIR CONDITIONER
COMPRESSOR LOCK
CONTROLLERRADIATOR
FAN MOTOR
RELAYCLO)
A-36
A-45
@!A
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14-6COOLING - Troubleshooting.TROUBLESHOOTING HINTS
1. Neither the radiator fan nor condenser fan
rotate at all.
l Check fusible link No. 5.
2. Only the condenser fan does not operate.
l Check dedicated fuse No. 8.
3. The radiator fan and condenser fan do not
operate in the low speed mode, but operate
otherwise.
(1) The A/C compressor magnet clutch does not
enter the “ON” state.
l Check whether the output of the auto
compressor control unit is available.
NOTEFor troubleshooting of the air conditioner
control unit, refer to GROUP 55.
(2) The A/C compressor magnet clutch enters
the “ON” state.
l Check the resistor.
Fan Operating Model Check the radiator fan motor relay (LO)
and condenser fan motor relay (LO).
l Check the therm0 sensor (for radiator
fan).
(3) The radiator fan does not rotate when the ailconditioner switch is turned ON.
l Check the radiator fan motor control
relay.4. The radiator fan and condenser fan do not
operate in the high speed mode, but operate
otherwise.l Check the therm0 sensor (for condenser
fan).
lCheck the radiator fan motor relay (HI) and
condenser fan motor relay (HI).Air
conditionerswitch
Switch conditionsTherm0 sensor
For radiator fan
For condenser fan
ON at 85
k 4°C
ON at 95 t 4°C
(185 f 7°F) or more(203 + 7°F) or more
OFF at 77°C (171°F)
OFF at 87°C (189°F)or less
or lessEngine coolant
temperature switch
(for air conditioner
cut-off) OFF at 115
+3°C (239 2 5°F) or
over, ON at 108°C
(226°F) or lessFan revolving operation
conditionCondenser fan motor
Condenser fan motorRadiator fan motor
operates
In HIGH only
when it receives input
from condenser fan
motor relay (HI) and
U-0).I/I/
OFF
OFF
OFFOFF
IOFFIOFF
ONLOWOFF
ON
HIGHLOW
OFF
OFFLOWLOW
OFF
ONON
LOWLOW
ON
HIGH
ONHIGH
OFF
HIGHLOW
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