1991 MITSUBISHI ECLIPSE sensor

COOLING - Troubleshootina7-5
TRO,UBLESHOOTlNG
Symptom
OverheatProbable causeInsufficient engine coolant
Too high an anti-freeze concentrationRemedy
Replenish
Correct anti-freeze
concentration
Loose or broken drive belt
Replace
Inoperative electric cooling fan
Faulty thermosensor
Replace
Faulty electrical motorReplace
Faulty radiator fan relayReplace
Damaged or blocked (insufficiently ventilated) radiator finsCorrect
Water leaks
Damaged radiator core joint
Replace
Corroded or cracked hosesReplace
(radiator hose, heater hose, etc.)
Loose bolt or leaking gasket in water outlet fitting
(thermostat)
Loose water pump mounting bolt or leaking gasket
Faulty cap valve or setting of spring
Loose intake manifold bolts or leaking from gasket
Cracked intake manifold
Faulty automatic transaxle oil cooler operation
Blocked or collapsed hose and pipe
Loose hose and pipe connection
Faulty thermostat operation
Faulty water pump operation
Water passage clogged with slime or rust deposit or
foreign substanceCorrect or replace
Correct or replace
Replace
Retorque bolts or replace
gasket
Replace
Replace
Correct
Replace
Replace
Clean
Jo rise in temperatureFaulty thermostatReplace

COOLING - Troubleshooting7A7
OPERATION
1. When the output of the air conditioner*--control unit is “LO” (OV)(when the
compressor magnet clutch isdeenergized)
l When the ignition switch is at “ON” , and if
engine coolant temperature rises to
85°C
(185”F), the thermosensor contacts close,
causing current to flow through the radiator
fan motor relay (coil), thermosensor and
ground, causing the radiator fan motor relay
contacts to close.
l Current flows through the radiator fan motor
relay contacts, radiator fan motor and ground,causing the radiator fan motor to rotate.
2. When the output of the air conditioner
control unit is “HI” (approx. 12V)(when the
compressor magnet clutch is
energized)l If the therm0 sensor is “ON” when the
engine coolant temperature exceeds
85°C
(185°F). the condenser fan motor control relay
is also “ON”, thus the condenser fan as well
as the radiator fan start rotating at a high
speed.
TROUBLESHOOTING HINTS
1. Neither the radiator fan nor condenser fanrotate at
all.l Check sub fusible link
No.3.
2. Only the condenser fan does not operate.l Check dedicated fuse
No.5.
3. The radiator fan and condenser fan do notoperate
in the low speed mode, but operateotherwise.
(1)The A/C compressor magnet clutch does not
enter the “ON” state.
l Check whether the output of the air con-
ditioner control unit is available.
NOTEFor troubleshooting of the air conditioner
control unit, refer to GROUP 24.
(2)The A/C compressor magnet clutch enters
the “ON” state.
l Check the resistor.Conditions
under which the Air Conditioner Control Unit Outputs a “HI” Signal
Ignition switch (IG2)
Blower switchAir conditioner switch
Compressor magnet clutch
ON
ON
ON
ON
Remarksl If any of the switches and sensors is OFF,
the air conditioner control unit will
output a “LO” signal (OV).
Fan Operating Mode
Switch conditions
Air conditioner switch
Therm0 sensor
LO
(OV)OFFLO
(OV)ONHI
(12V)OFFHI
(12V)ONFan rotating condition
Cooling (radiator) fanCondenser fan
OFFOFF
HIGHOFF
LOWLOW
HIGHHIGH
NOTE
_-The therm0 sensor is ON when the temperature reaches 85°C (185°F) or more.

7-12COOLING - Radiator
RADIATORPre-removal Operation
@Draining of the Engine Coolant(Refer to GROUP O-Maintenance(Refer to GROUP II-Air Cleaner.)
Service.)
I I
@Removal of Air Cleaner BracketORefilling of the Engine Coolant(Refer to GROUP 11 -Air Cleaner.)(Refer to GROUP O-MaintenanceService.)*Checking Automatic Transaxle FluidLevel and Refilling If Necessary
9-14 Nm
_
4-6 Nm3-4 ft.lbs.Removal steps
1 Drain plug2. Cap3. Overflow tube.
4-9 Nm3-4 ft.lbs.
4. Water level switch connector
5. Reserve tank~~ l +6. Radiator upper hose
+e e+ 7. Radiator lower hose
*I)8. Automatic transaxle oil cooler hoses9. Therm0 sensor connectorIO. Radiator fan motor connector
11. Condenser fan motor connector12. Upper insulator
04AOOS7
07A0049
13. Radiator assembly14. Condenser fan motor assembly15. Radiator fan motor assembly
16. Thermosensor
17. Lower insulator
NOTE(1) Reverse the removal procedures to reinstall.(2) +e : Refer to “Service Points of Removal”.(3) l + : Refer to “Service Points of Installation”

COOLING- Radiator7-13Mating
marks
04A0020
SERVICE POINTS OF REMOVALN07QBAH
6. REMOVAL OF RADIATOR UPPER HOSE/7. RADIATOR
LOWER HOSEAfter making mating marks on the radiator hose and the
hose clamp, disconnect the radiator hose.
8. DISCONNECTION OF AUTOMATIC TRANSAXLE OIL
COOLER HOSESUse a plug or otherwise cover the hose and nipple part of
the radiator so that dust, dirt, foreign materials, etc. do not
enter after the hose has been disconnected from the
radiator.
INSPECTIONNo7OcAMl Check for foreign material between radiator fins.
l Check the radiator fins for bent, or damage.
l Check the radiator for corrosion, damage rust or scale.
lCheck the radiator hoses for cracks, damage or deteriora-
tion.l Check the reserve tank for damage.
lCheck the automatic transaxle oil cooler hoses for cracking,damage or deterioration.
RADIATOR FAN MOTOR INSPECTION(1) Check to be sure that the radiator fan rotates when batten/
voltage is applied between terminals (as shown in the
figure).
(2) Check to see that abnormal noises are not produced, whilemotor is turning.
THERM0 SENSOR INSPECTIONCheck for continuity with the therm0 sensor in hot water.
NOTEImmerse therm0 sensor in hot water up to mounting thread to
check for continuity.

COOLING - Water Hose and Water Pipe <1.8L Engine>
WATER HOSE AND WATER PIPE
<1.8L Engine>
_-REMOVAL AND INSTALLATIONNO’IIA-A27-33 Nm
20-24 ftlbs.
12-15 Nms- 11 ft.lbs.Removal steps
1 Air intake hose
2. Engine oil level gauge guide3. O-ring
4. Self locking nut
5. Gasket
6. Oxygen sensor harness connector
7. Exhaust manifold cover (A)
8. Engine hanger9. Exhaust manifold
IO. Exhaust manifold gasket
11. Exhaust manifold cover(B)NOTE(1) Reverse the removal procedures to reinstall.(2) m : Non-reusable parts

7-28COOLING- Water Hose and Water Pipe <2.0L DOHC Engine (Non-Turbo)>
<2.0L DOHC Engine (Non-Turbo)>
REMOVAL AND INSTALLATION
Post-installgtion Pperation@Supplying of the Engine Coolant(FF$efeet; GROUP O-Maintenance
6
/5
/l--5ia
225-30 Nm
18-22
ft.lbs.
12-1s Nrn9-11 ft.lbs.
Removal steps1 Air intake hose
2. Condenser fan motor assembly
3. Self-locking nut4. Gasket
5. Oxygen sensor harness connector
6. Exhaust manifold cover (A)7. Self-locking nut
8. Engine hanger
04A01059. Exhaust manifold
10. Exhaust manifold gasket11. Exhaust manifold cover(B)
NOTE(1) Reverse the removal procedures to reinstall.(21 m : Non-reusable parts

COOLING -Water Hose and Water Pipe <2.0L DOHC Engine (Turbo)>7-31WATER HOSE AND WATER PIPE
7--<2.0L DOHC Engine (Turbo)>
REMOVAL AND INSTALLATION
N071A-C
. .
ation OperationPost-installi@Filling of the Engine Oil(Refer to GROUP g-EngineaFilling of the
Engine Coolant(Refer to GROUP 7-ServiceAdjustment Procedures.)
Pre-removal OperationeDraining of the Engine Coolant(Refer to GROUP 7-ServiceAdjustment Procedures.)*Draining of the Engine Oil(Refer to GROUP g-Engine
25-30 Nm
18-22 ftlbs.4n-47 ft.lbs.
w35-45 N/m12-15 Nm25-33 ft.lbs.
9- 11ft.lbs.----Q&Removal steps
1. Condenser fan motor assembly2. Oxygen sensor harness connector3. Engine oil level gauge guide4. O-ring5. Connection for air intake hose6. Connection for vacuum hose7. Connection for air hose A8. Connection for vacuum hose9. Heat protector A10. Heat protector B
4*11. Power steering oil pump
12. Oil pump bracket
13. Self-locking nut
14. Engine hanger22-29
ft.lbs. 29-43 ft.lbs.
15. Eye bolt16. Gasket17. Connection for water hose
I)+ 18. Connection for water pipe B19. Self-locking nut20. Gasket21. Exhaust manifold22. Exhaust manifold gasket
23. Ring
24. Gasket
05m154