Mitsubishi Grandis. Manual — part 326

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-189

35

Rear air mix damper motor
(COOL) <Vehicles with dual
automatic A/C>

When the rear air conditioner is
moved to the COOL position

System voltage

When the rear air conditioner is
moved to the HOT position

0

− 1 V

36

Rear air mix damper motor
(HOT) <Vehicles with dual
automatic A/C>

When the rear air conditioner is
moved to the HOT position

System voltage

When the rear air conditioner is
moved to the COOL position

0

− 1 V

37

Outside/inside air selection
damper motor (Fresh air
position)

When setting the Fresh air position 0

− 1 V

When setting the air recirculation
position

System voltage

38

Outside/inside air selection
damper motor (Air
recirculation position)

When moving to air recirculation
position

0

− 1 V

When moving to fresh air position

System voltage

35~42

−

−

−

43

ILL power supply

Lighting switch: ON

System voltage

44

ILL earth

Always

0 V

45

Front blower relay

Ignition switch: IG2

0

− 1 V

46

PTC heater relay <Vehicles
with dual automatic A/C>

PTC heater: ON

0

− 1 V

PTC heater: OFF

System voltage

51

Rear temperature control
lever indicator <Vehicles with
dual automatic A/C>

Rear air volume adjusting switch:
OFF

System voltage

Rear air volume adjusting switch:
Other than OFF

0

− 1 V

52

Rear air conditioner switch
indicator (AUTO) <Vehicles
with dual automatic A/C>

Rear air volume adjusting switch:
AUTO

0

− 1 V

53

Rear air conditioner switch
indicator (Lo) <Vehicles with
rear heater, rear cooler or dual
automatic A/C>

Rear air volume adjusting switch: 1 0

− 1 V

54

Rear air conditioner switch
indicator (Me) <Vehicles with
rear heater, rear cooler or dual
automatic A/C>

Rear air volume adjusting switch: 2 0

− 1 V

55

Rear air conditioner switch
indicator (Hi) <Vehicles with
rear heater, rear cooler or dual
automatic A/C>

Rear air volume adjusting switch: 3 0

− 1 V

56

Rear blower relay

Ignition switch: ON

0

− 1 V

57

−

−

−

Terminal
No.

Check items

Check conditions

Normal conditions

ON-VEHICLE SERVICE

HEATER, AIR CONDITIONER AND VENTILATION

55-190

ON-VEHICLE SERVICE

COMPRESSOR DRIVE BELT
ADJUSTMENT

M1552001000410

Refer to GROUP 11A, On-vehicle Service

− Drive

Belt Tension Check

P.11A-7

.

DISCHARGING SYSTEM

M1552013000127

Use the refrigerant recovery unit to discharge
refrigerant gas front the system.
NOTE: Refer to the Refrigerant Recovery and
Recycling Unit instruction Manual for operation of the
unit.

58

Rear fan switch indicator
<Vehicles with rear heater,
rear cooler or dual automatic
A/C>

Rear fan switch: Other than OFF

0 V

59

Rear power transistor
(DRAIN)

Rear air volume adjusting switch: 3
(Preset temperature 20

°C)

0

− 2 V

60

Rear power transistor (GATE) Rear air volume adjusting switch: 3

(Preset temperature 20

°C)

System voltage

61~64

−

−

−

65

Rear air conditioner switch
(Shielded wire) <Vehicles with
rear heater, rear cooler or dual
automatic A/C>

Always

0 V

66

Rear air conditioner switch
(Hi) <Vehicles with rear
heater, rear cooler or dual
automatic A/C>

Rear air volume adjusting switch: 3 Approximately 5 V

67

Rear air conditioner switch
(Me) <Vehicles with rear
heater, rear cooler or dual
automatic A/C>

Rear air volume adjusting switch: 2 Approximately 5 V

68

Rear air conditioner switch
(Lo) <Vehicles with rear
heater, rear cooler or dual
automatic A/C>

Rear air volume adjusting switch: 1 Approximately 5 V

69

Rear air conditioner switch
(AUTO) <Vehicles with dual
automatic A/C>

Rear air volume adjusting switch:
AUTO

Approximately 5 V

70

Rear air conditioner switch
(OFF) <Vehicles with rear
heater, rear cooler or dual
automatic A/C>

Rear air volume adjusting switch:
OFF

Approximately 5 V

71

Rear fan switch input

Rear fan switch: ON (switch
pushed)
Ignition switch: IG2

System voltage

72

Rear air conditioner switch
indicator power supply

Rear air volume adjusting switch:
Other than OFF

System voltage

Terminal
No.

Check items

Check conditions

Normal conditions

ON-VEHICLE SERVICE

HEATER, AIR CONDITIONER AND VENTILATION

55-191

CHARGING

M1552001200447

1. With the handles turned back all the way (valve

closed), install the adaptor valve to the
low-pressure side of the gauge manifold.

2. Connect the charging hose (blue) to the adaptor

valve.

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

charging hose (blue).

CAUTION

• Use tools that are suited to R134a.
• To install the quick joint, press section when

connecting, run your hand along the hose
while pressing to ensure that there are no
bends in the hose.

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

low- pressure service valve.
NOTE: The low-pressure service valve should be
connected to the flexible suction hose.

5. Close the high and low-pressure valves of the

gauge manifold.

CAUTION

Be sure to connect the power plug of the vacuum
pump to the vacuum pump adapter, and then
connect the power plug of the adapter to a 100-V
outlet.
6. Install the vacuum pump adaptor to the vacuum

pump.

7. Connect the charging hose (yellow) to the R-134a

connection port of the vacuum pump adaptor.

8. Tighten the adaptor valve handle (valve open).
9. Open the low-pressure valve of the gauge

manifold.

10.Turn the power switch of the vacuum pump to the

ON position.
NOTE: Even if the vacuum pump power switch is
turned ON, the vacuum pump will not operate
because of the power supply connection in step
(6).

CAUTION

Do not operate the compressor for evacuation.

11.Turn the vacuum pump adaptor switch to the

R134a side to start the vacuum pump.

12.Evacuate to a vacuum reading of 100 kPa or

higher (takes approx. 10 minutes).

AC212526AB

A

Sleeve

Low-pressure
service valve

Quick
joint
(for low
pressure)

Switch

Vacuum
pump

Power supply
plug

Vacuum
pump
adaptor

R-12
connection
port

Charging hose
(blue)

Adapter
valve

Charging hose
(yellow)

Gauge manifold

Switch

R-134a
connection
port

Low-pressure
valve

High-pressure
valve

AC212535

Vacuum
pump

Low-pressure
service valve

AB

Vacuum pump
adaptor switch

ON-VEHICLE SERVICE

HEATER, AIR CONDITIONER AND VENTILATION

55-192

CAUTION

Do not operate the compressor in the vacuum
condition; damage may occur.
13.Loosen the valve of the adapter valve fully (valve

closed), and turn off the vacuum pump adapter
switch. Then leave it for five minutes.

14.Check the system for proper sealing (negative

pressure should not decrease).

15.Connect the service can valve to the service can

with the handle loosened fully (valve closed).

16.Turn the handle of the adaptor valve back all the

way (valve closed), remove it from the gauge
manifold and install the service can.

17.Tighten the handle of the charging valve (valve

closed) to puncture the service can.

CAUTION

If the service can is inverted, liquid refrigerant
may be drawn into the compressor damaging it
by liquid compression. Keep the service can
upright to ensure that refrigerant is charged in
gas state.

18.Turn the handle of the charging valve back (valve

open) and tighten the handle of the adaptor valve
(valve open) to charge the system with refrigerant.

19.If the refrigerant is not drawn in, turn the handle of

the adaptor valve back all the way (valve closed).

20.Check for gas leaks using a leak detector. If a gas

leak is detected, re-tighten the connections, and
then repeat the charging procedure from
evacuation in step (11).

CAUTION

The leak detector for R-134a should be used.
21.Start the engine.
22.Operate the A/C and set to the lowest

temperature (MAX. COOL).

23.Fix the engine speed at 1,500 r/min.

CAUTION

If the service can is inverted, liquid refrigerant
may be drawn into the compressor damaging it
by liquid compression. Keep the service can
upright to ensure that refrigerant is charged in
gas state.
24.Tighten the handle of the adaptor valve (valve

open) to charge the required volume of
refrigerant.

AC212536

Valve open

Valve close

Charging valve

Service can

Adaptor valve

AB

AC212537

Charging valve

Service can
(Refrigerant container)

Low-pressure
service valve

AB