coolant temperature MITSUBISHI 380 2005 Workshop Manual

ENGINE AND TRANSMISSION
CONFIGURATION DIAGRAMS80-8
B-101 (3-GR) IGNITION COIL 1
B-102 (3-GR) IGNITION COIL 3
B-103 (3-GR) IGNITION COIL 5
B-104 (2-B) ENGINE COOLANT TEMPERATURE
SENSOR
B-106 (3-B) CAMSHAFT POSITION SENSORB-107 (3-GR) OUTPUT SHAFT SPEED SENSOR
B-108 (10-GR) A/T CONTROL SOLENOID VALVE
ASSEMBLY
B-109 (3-B) INPUT SHAFT SPEED SENSOR
B-110 (10-B) TRANSMISSION INHIBITOR
(RANGE) SWITCH

GENERAL DESCRIPTION
HEATER, AIR CONDITIONING AND VENTILATION55-4
OPERATION
.
CONDENSER FAN AND RADIATOR FAN
CONTROL
The ECU judges the required revolution speed of
radiator fan motor and condenser fan motor using
the input signals transmitted from A/C switch, output
shaft speed sensor and engine coolant temperature
sensor. The ECU activates the fan control relays to
drive the radiator fan motor and condenser fan
motor.
.
COMPRESSOR CONTROL
When operating the air conditioning switch
The air thermo sensor, which senses the temper-
ature of the air flowing out of the evaporator,
deactivates the compressor at 3
C (37.4F) or
below.
The dual pressure switch turns OFF when the
refrigerant pressure becomes excessively high or
low, thus protecting the compressor circuit (See
Table below).
When the air thermo sensor is activated, and the
ignition switch, blower switch, and air condition-
ing switch are ON, the A/C compressor clutch
relay is energized.
When operating the mode selection dial
The air conditioning will work when the mode
selection dial is set to the "Defroster" or
"Defroster/foot" position, or the temperature con-
trol dial is set to the "MAX A/C" position. In other
dial positions, when the air conditioning switch is
turned on, the air conditioning will work.
A/C Compressor Clutch Relay ON Conditions
Ignition switch (IG2) ONNOTE: A/C compressor clutch relay is
de-energized when any one switch, sensor
or control unit shown on the left turns off.
NOTE: The components marked by
*
communicate with the ECU. If the air thermo
sensor detects a temperature of 3
C
(37.4
F), the A/C-ECU will turn off the A/C
compressor clutch relay. Blower switch ON
Air conditioning switch, mode selection dial
defroster, defroster/foot position or temperature
control MAX A/CON
Air thermo sensor*
Pressure detected
by A/C pressure
sensor2940 kPa or less (If the
refrigerant pressure exceeds
2940 kPa, A/C compressor
clutch relay is not ON
condition until the refrigerant
pressure has been measured
up to 2350 kPa or less.)ON
190 kPa or more (If the
refrigerant pressure falls short
of 190 kPa, A/C compressor
clutch relay is not ON
condition until the refrigerant
pressure has been measured
up to 220 kPa or more.)
A/C compressor clutch relay driving transistor (within
ecu)ON

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-133
DATA LIST REFERENCE TABLEM1554005100136
MUT-III
DIAGNOSTIC
TOOL DISPLAYITEM
NO.INSPECTION ITEM INSPECTION REQUIREMENT NORMAL VALUE
Inside
temperature
sensor59 Interior temperature
sensorIgnition switch: ON Inside air
temperature and
temperature
displayed on the
diagnostic tool are
identical.
Outside
temperature
sensor58 Outside temperature
sensorIgnition switch: ON Outside air
temperature and
temperature
displayed on the
diagnostic tool are
identical.
Air thermo sensor 20 Air thermo sensor Ignition switch: ON The temperature
measured behind
the evaporator
matches the
displayed value on
the diagnostic tool
while the engine is
cold.
Pressure sensor 61 A/C pressure sensor Ignition switch: ON Measured refrigerant
pressure is nearly
equal to the value
shown on the
diagnostic tool
(MPa).
Water
temperature
sensor62 Engine coolant
temperature sensor
(Data received by
CAN
Communication)Ignition switch: ON Engine coolant
temperature and
temperature
displayed on the
diagnostic tool are
identical.
Photo sensor 67 Photo sensor Ignition switch: ON Amount of light is
proportional to
voltage displayed on
the diagnostic tool.
Air mix
potentiometer63 Air mixing damper
control motor
potentiometerIgnition switch: ON Damper
positionOpening degree (V)
MAX. HOT Approx. 5
MAX. COOL Approx. 0
Air mix
potentiometer
(Target)64 Target value for air
mixing damper
control motor
potentiometerIgnition switch: ON Damper
positionOpening degree (V)
MAX. HOT Approx. 5
MAX. COOL Approx. 0

ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-149
A/C COMPRESSOR CLUTCH RELAY CONTINUITY
CHECK
IDLE-UP OPERATION CHECK
M1552001600401
Before inspection and adjustment, set vehicle in the following
condition:
Engine coolant temperature: 80 90 C (176.0 194.0 F)
Lights, electric cooling fan and accessories: OFF
Transmission: Neutral ("N" or "P" position)
Steering wheel: Straightforward
1. Check whether or not the idle speed is the standard value.
Standard value: 680
50 r/min
2. Turn on the air conditioning switch and the blower speed
selection dial. Engine idling speed should be within the
standard value:
Standard value: 680
50 r/min
NOTE: The Electronic control unit determines whether the
A/C load is low or high according to the output signal from
the A/C-ECU.
NOTE: It is not necessary to make an adjustment, because
the idling speed is automatically controlled by the ENGINE
ECU. BATTERY
V O LTA G ETESTER
CONNECTIONSPECIFIED
CONDITION
Not applied 1
4 Open circuit
Connect
terminal 2 to the
positive battery
terminal
Connect
terminal 3 to the
negative battery
terminal1
4 Less than 2 ohms

SENSOR
COMPONENT LOCATIONS70-9
NOTE: The * symbols indicate equipped at both sides.Engine coolant temperature sensor F Throttle body assembly (Incorporating
throttle position sensor)E
Front impact sensor M Wheel speed sensor (front) Y
Side impact sensor a Wheel speed sensor (rear) b NAME SYMBOL NAME SYMBOL

GENERAL DESCRIPTION
ENGINE COOLING14-2
GENERAL DESCRIPTIONM1141000100401
The cooling system is designed to keep every
part of the engine at appropriate temperature in
whatever condition the engine may be operated.
The cooling method is of the water-cooled, pres-
sure forced circulation type in which the water
pump pressurizes coolant and circulates it
throughout the engine. If the coolant temperature exceeds the prescribed temperature, the thermo-
stat opens to circulate the coolant through the
radiator as well so that the heat absorbed by the
coolant may be radiated into the air. The water
pump is of the centrifugal type and is driven by
the drive belt from the crankshaft. The radiator is
the corrugated fin, down flow type.
SPECIAL TOOLM1141000600279
ENGINE COOLING DIAGNOSIS
INTRODUCTIONM1141005300347
The system cools the engine so that it does not over-
heat and maintains the engine at an optimum tem-
perature. The system components are the radiator,
water pump, thermostat, condenser and fan assem-
blies. Possible faults include low coolant, contamina-
tion, belt loosening and component damage.
TROUBLESHOOTING STRATEGYM1141005200340
Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure to find
most of the engine cooling faults.
1. Gather information from the customer.2. Verify that the condition described by the
customer exists.
3. Find and repair the malfunction by following the
SYMPTOM CHART.
4. Verify that the malfunction is eliminated. TOOL TOOL NUMBER AND
NAMESUPERSESSION APPLICATION
MB991871
LLC changerGeneral service tool Coolant refilling

ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-4
INSPECTION PROCEDURE 2: Engine Overheating
DIAGNOSIS
STEP 1. Remove the radiator cap and check for coolant
contamination.
Q: Is the coolant contaminated with rust and oil?
YES : Replace it. Refer to P.14-27.
NO : There is no action to be taken. Go to Step 2.
STEP 2. Check the radiator cap valve opening pressure.
NOTE: Be sure that the cap is clean before testing. Rust or
other foreign material on the cap seal will cause an improper
reading.
(1) Use a cap adapter to attach the cap to the tester.
(2) Increase the pressure until the gauge indicator stops
moving.
Minimum limit: 83 kPa (12 psi)
Standard value: 93
123 kPa (14 18 psi)
Q: Does the reading remain at or above the minimum limit?
YES : Go to Step 3.
NO : Replace the radiator cap. Then go to Step 5.
STEP 3. Check thermostat operation.
Refer to 38.
Q: Does the thermostat operate correctly?
YES : Go to Step 4.
NO : Replace the thermostat, then go to Step 5.
STEP 4. Check the drive belt for slippage or damage.
Refer to GROUP 00, Maintenance Service
Drive Belts
(Check Condition). <3.8L Engine>39 .
Q: Is the drive belt loose or damaged?
YES : Adjust or replace the drive belt, then go to Step 5.
NO : There is no action to be taken.
STEP 5. Retest the system.
Check the engine coolant temperature.
Q: Is the engine coolant temperature abnormally high?
YES : Return to Step 2.
NO : The procedure is complete.

ON-VEHICLE SERVICE
ENGINE COOLING14-29
Do not use alcohol or methanol anti-freeze or any
engine coolants mixed with alcohol or methanol
anti-freeze. The use of an improper anti-freeze can
cause corrosion of the aluminum components.
8. By referring to the section on coolant, select an appropriate
concentration for safe operating temperature within the
range of 30 to 60 %. Use special tool MB991871 to refill the
coolant. A convenient mixture is a 50 % water and 50 %
antifreeze solution [freezing point:
31C (32.8 F)].
Recommended antifreeze: Long Life Antifreeze
Coolant or an equivalent
Quantity:
8.7 Litres
NOTE: For how to use special tool MB991871, refer to its
manufacturer’s instructions.
9. Reinstall the radiator cap.
10.Start the engine and let it warm up until the thermostat
opens.
11.After repeatedly revving the engine up to 3,000 r/min several
times, stop the engine.
12.Remove the radiator cap after the engine has cooled, and
pour in coolant up to the brim. Reinstall the cap.
Do not overfill the radiator condenser tank assembly.
13.Add coolant to the radiator condenser tank assembly
between the "FULL" and "LOW" mark if necessary.
ENGINE COOLANT CONCENTRATION TESTM1141001100396
Refer to GROUP 00, RECOMMENDED LUBRICANTS AND
LUBRICANT CAPACITIES TABLE 35.
FAN CONTROLLER CHECKM1141007400113
1. Remove the fan controller connector.
2. Turn the ignition switch to the "ON" position, and measure
the voltage between the harness-side connector terminals.
Standard value: System voltage

THERMOSTAT
ENGINE COOLING14-36
14. ENGINE COOLANT
TEMPERATURE SENSOR
CONNECTOR
15. CAPACITOR CONNECTOR
16. CAMSHAFT POSITION SENSOR
CONNECTOR
17. INHIBITOR SWITCH SENSOR
CONNECTOR
18. A/T CONTROL SOLENOID VALVE
ASSEMBLY CONNECTOR
19. OUTPUT SHAFT SPEED
SENSOR CONNECTOR
20. INPUT SHAFT SPEED SENSOR
CONNECTOR REMOVAL STEPS (Continued)
REMOVAL STEPS
<> >>B<<21. RADIATOR LOWER HOSE
CONNECTION22. WATER INLET FITTING>>A<<23. THERMOSTATREMOVAL STEPS (Continued)

WATER HOSE AND WATER PIPE
ENGINE COOLING14-40
WATER HOSE AND WATER PIPE
REMOVAL AND INSTALLATIONM1141003300493
REMOVAL SERVICE POINT
.
<> RADIATOR UPPER HOSE DISCONNEC-
TION
After making mating marks on the radiator hose and hose
clamp, disconnect the radiator hose.
Pre-removal and Post-installation Operation
Thermostat Removal and Installation (Refer to 35).
REMOVAL STEPS
<> >>C<<1. RADIATOR UPPER HOSE
CONNECTION
2. HEATER HOSE CONNECTION
5. THERMOSTAT HOUSING
6. GASKET>>B<<7. ENGINE COOLANT
TEMPERATURE SENSOR
8. WATER PUMP INLET PIPE
>>A<<9. O-RINGREMOVAL STEPS (Continued)