Mitsubishi Lancer Evolution IX. Manual - part 558

ON-VEHICLE SERVICE

HEATER, AIR CONDITIONER AND VENTILATION

55-105

2. Close the high and low-pressure valve of the 

gauge manifold.

3. Connect the charging hose (blue) to the 

low-pressure valve and connect the charging 
hose (red) to the high-pressure valve of the gauge 
manifold.

CAUTION

• To connect the quick joint, press section A 

firmly against the service valve until a click is 
heard.

• When connecting, run your hand along the 

hose while pressing to ensure that there are 
no bends in the hose.

4. Install the quick joint (for low-pressure) to the 

charging hose (blue), and connect the quick joint 
(for high-pressure) to the charging hose (red).

NOTE: The high-pressure service valve is on the 
A/C pipe and the low-pressure service valve is on 
the suction hose.

5. Connect the quick joint (for low-pressure) to the 

low-pressure service valve and connect the quick 
joint (for high-pressure) to the high-pressure 
service valve.

6. Start the engine.
7. Set the A/C controls as follows:

• A/C switch: A/C − ON position

• Mode selection: FACE position

• Temperature control: MAXIMUM COOLING posi-

tion

• Air selection: RECIRCULATION position

• Blower switch: "4" (Fast) position 

8. Keep engine speed to idling speed with A/C clutch 

engaged.

9. Engine should be warmed up with doors and all 

windows opened.

10.Insert a thermometer in the centre air outlet and 

operate the engine for 20 minutes.

NOTE: If the clutch cycles, take the reading before 
the clutch disengages.
11.Note the discharge air temperature.

PERFORMANCE TEMPERATURE CHART

REFRIGERANT LEAK REPAIR 
PROCEDURE

M1552001500385

LOST CHARGE

If the system has lost all charge due to a leak:
1. Evacuate the system (Refer to 

P.55-104

).

2. Charge the system with approximately 480 

− 520 

g of refrigerant.

3. Check for leaks.
4. Discharge the system.
5. Repair leaks.

AC001388

Low-pressure
valve

High-pressure
valve

Gauge manifold

Charging
hose (red)

A

Sleeve

Charging
hose (blue)

Adaptor valve
(for low-
pressure)

Low-
pressure
service
valve

High-
pressure
service
valve

AB

Adaptor valve
(for high-
pressure)

AC304576

Thermometer

AB

Garage ambient temperature 

°C

20

25

30

35

Discharge air temperature 

°C

8.0 

− 11.0

12.0 

− 16.0

17.0 

− 21.0

22.5 

− 27.5

Compressor high pressure kPa

740 

− 840

950 

− 1,050

1,160 

− 1,300

1,360 

− 1,550

Compressor low pressure kPa

150 

− 190

190 

− 240

240 

− 300

300 

− 375

ON-VEHICLE SERVICE

HEATER, AIR CONDITIONER AND VENTILATION

55-106

CAUTION

Replacement filter-drier units must be sealed 
while in storage. The drier used in these units will 
saturate water quickly upon exposure to the 
atmosphere. When installing a drier, have all 
tools and supplies ready for quick assembly to 
avoid keeping the system open any longer than 
necessary.
6. Replace receiver drier.
7. Evacuate and charge system.

LOW CHARGE

If the system has not lost all of its refrigerant charge; 
locate and repair all leaks. If it is necessary to 
increase the system pressure to find the leak 
(because of an especially low charge) add refriger-
ant. If it is possible to repair the leak without dis-
charging the refrigerant system, use the procedure 
for correcting low refrigerant level.

HANDLING TUBING AND FITTINGS

Kinks in the refrigerant tubing or sharp bends in the 
refrigerant hose lines will greatly reduce the capacity 
of the entire system. High pressures are produced in 
the system when it is operating. Extreme care must 
be exercised to make sure that all connections are 
pressure tight. Dirt and moisture can enter the sys-
tem when it is opened for repair or replacement of 
lines or components. The following precautions must 
be observed. The system must be completely dis-
charged before opening any fitting of connection in 
the refrigeration system. Open fittings with caution 
even after the system has been discharged. If any 
pressure is noticed as a fitting is loosened, allow 
trapped pressure to bleed off very slowly.
Never attempt to rebend formed lines to fit. Use the 
correct line for the installation you are servicing. A 
good rule for the flexible hose lines is keep the radius 
of all bends at least 10 times the diameter of the 
hose.
Sharper bends will reduce the flow of refrigerant. The 
flexible hose lines should be routed so that they are 
at least 80 mm from the exhaust manifold. It is good 
practice to inspect all flexible hose lines at least once 
a year to make sure they are in good condition and 
properly routed.

On standard plumbing fittings with O-rings, these 
O-rings are not reusable.

COMPRESSOR NOISE CHECK

M1552008700379

You must first know the conditions when the noise 
occurs. These conditions are: weather, vehicle 
speed, in gear or neutral, engine temperature or any 
other special conditions.
Noises that develop during A/C operation can often 
be misleading. For example: what sounds like a 
failed front bearing or connecting rod, may be 
caused by loose bolts, nuts, mounting brackets, or a 
loose clutch assembly. Verify accessory drive belt 
tension (power steering or alternator).
Improper accessory drive belt tension can cause a 
misleading noise when the compressor is engaged 
and little or no noise when the compressor is disen-
gaged.
Drive belts are speed-sensitive. That is, at different 
engine speeds, and depending upon belt tension, 
belts can develop unusual noises that are often mis-
taken for mechanical problems within the compres-
sor.

ADJUSTMENT

1. Select a quiet area for testing. Duplicate 

conditions as much as possible. Switch the 
compressor on and off several times to clearly 
identify compressor noise. To duplicate high 
ambient conditions (high head pressure), restrict 
air flow through the condenser. Install a manifold 
gauge set to make sure discharge pressure 
doesn't exceed 2,070 kPa.

2. Tighten all compressor mounting bolts, clutch 

mounting bolt, and compressor drive belt. Check 
to assure clutch coil is tight (no rotation or 
wobble).

3. Check refrigerant hoses for rubbing or 

interference that can cause unusual noises.

4. Check refrigerant charge (Refer to 

P.55-104

).

5. Recheck compressor noise as in Step 1.
6. If noise still exists, loosen compressor mounting 

bolts and retighten. Repeat Step 1.

7. If noise continues, replace compressor and repeat 

Step 1.

ON-VEHICLE SERVICE

HEATER, AIR CONDITIONER AND VENTILATION

55-107

POWER RELAY CHECK

M1552008800428

BLOWER RELAY CONTINUITY CHECK

A/C COMPRESSOR RELAY, CON-
DENSER FAN RELAY (LO) AND (HI) CON-
TINUITY CHECK

IDLE-UP OPERATION CHECK

M1552001600683

1. Before inspection and adjustment, set vehicle in 

the following condition:

• Engine coolant temperature: 80 − 90 °C

• Lamps, electric cooling fan and accessories: Set 

to OFF

• Transmission: Neutral

• Steering wheel: Straightforward

2. Check whether or not the idle speed is the 

standard value. Refer to GROUP 13A, On-vehicle 
Service 

− Basic Idle Speed Adjustment 

P.13A-396

.

Standard value: 850 

± 50 r/min

3. When the A/C is running after turning the A/C 

switch to ON, and the blower switch to the 3(MH) 
or 4(HI) position, check to be sure that the idle up 
speed is at the standard value.

Standard value: 850 

± 50 r/min

NOTE: It is not necessary to make an adjustment, 
because the idling speed is automatically 
adjusted by the ISC system. If, however, a devia-
tion from the standard value occurs for some rea-
son, check the ISC system.

Battery voltage Tester 

connection

Specified 
condition

Not applied

4 

− 5

Open circuit

• Connect 

terminal 3 to 
the positive 
battery 
terminal

• Connect 

terminal 1 to 
the negative 
battery 
terminal

4 

− 5

Less than 2 
ohms

AC310514AB

Blower relay

5

4

3

1

1 2 3

5

4

Battery voltage Tester 

connection

Specified 
condition

Not applied

1 

− 4

Open circuit

• Connect 

terminal 2 to 
the positive 
battery 
terminal

• Connect 

terminal 3 to 
the negative 
battery 
terminal

1 

− 4

Less than 2 
ohms

AC310515

A/C compressor relay

Condenser fan relay (HI)

Condenser fan relay (LO)

AB

1

4

3

2

2

4

X

1

3

Front of 
vehicle

HEATER CONTROL ASSEMBLY AND A/C SWITCH

HEATER, AIR CONDITIONER AND VENTILATION

55-108

CLEAN AIR FILTER REPLACEMENT 
PROCEDURE

M1552020100096

1. Remove the glove box (Refer to GROUP 52A, 

Instrument Panel 

P.52A-2

).

2. Remove the two screws as shown, and replace 

the clean air filter.

3. Install the glove box.

HEATER CONTROL ASSEMBLY AND A/C SWITCH

REMOVAL AND INSTALLATION

M1552002400659

AC309643

Clean air filter 

AC

AC504841

1

2

2

4

5

2

3

4

5

AB

Removal steps 

1.

Centre lower case (Refer to 
GROUP 52A, Instrument panel 
assembly 

P.52A-2

)

2.

Knob

3.

Automatic A/C control panel 
(A/C-ECU)

4.

Bracket

Removal steps (Continued)