Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Service manual — part 589

AC-15

General Description

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

Refrigerant recovery system
A

REFRIGERANT RECOVERY SYSTEM is used for the recovery and

recycling of A/C system refrigerant after contaminants and moisture
have been removed from the refrigerant.

Syringe
A graduated plastic

SYRINGE will be needed to add oil into the system

again. A syringe can be available at a pharmacy or drug store.

Vacuum pump
A

VACUUM PUMP is necessary (for a good working condition), and

may be available at either a refrigerant supplier or an automotive
equipment supplier.

Can tap
A

CAN TAP for the 397 g (14 oz) can is available at an automotive

equipment supplier.

Thermometer
A Pocket

THERMOMETER is available at either a industrial hardware

store or a refrigerant supplier.

Illustration

Tools and Equipment

AC-00014

AC-00015

AC-00016

AC-00017

AC-00018

AC-16

General Description

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

Electronic leak detector
An

ELECTRONIC LEAK DETECTOR can be available at either a spe-

cialty tool supplier or an A/C equipment supplier.

Weight scale
A

WEIGHT SCALE such as an electronic charging scale or a bath-

room scale with digital display will be needed, if a 13.6 kg (30 lb) refrig-
erant container is used.

Illustration

Tools and Equipment

AC-00019

AC-00020

AC-17

Air Conditioning System

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

2. Air Conditioning System

A: WIRING DIAGRAM

Refer to “Air Conditioning System” in the wiring diagram. <Ref. to WI-74, WIRING DIAGRAM, Air Condition-

ing System.>

B: INSPECTION

Refer to “Basic Diagnostic Procedure” for “HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)” section. <Ref. to

AC(diag)-2, Basic Diagnostic Procedure.>

C: NOTE

For procedure of each component in the air conditioning system, refer to the respective section.

• Blower motor unit assembly: <Ref. to AC-25, Blower Motor Unit Assembly.>

• Blower motor: <Ref. to AC-26, Blower Motor.>

• Power transistor (auto A/C model): <Ref. to AC-27, Power Transistor (Auto A/C Model).>

• Blower resistor (manual A/C model): <Ref. to AC-28, Blower Resistor (Manual A/C Model).>

• Heater core: <Ref. to AC-29, Heater Core.>

• Control unit (manual A/C model): <Ref. to AC-30, Control Unit (Manual A/C Model).>

• Control unit (auto A/C model): <Ref. to AC-31, Control Unit (Auto A/C Model).>

• Compressor: <Ref. to AC-32, Compressor.>

• Condenser: <Ref. to AC-34, Condenser.>

• Heater and cooling unit: <Ref. to AC-36, Heater and Cooling Unit.>

• Evaporator: <Ref. to AC-37, Evaporator.>

• Hose & pipe: <Ref. to AC-41, Hose and Pipe.>

• Ambient sensor (auto A/C model): <Ref. to AC-44, Ambient Sensor (Auto A/C Model).>

• Sunload sensor (auto A/C model): <Ref. to AC-46, Sunload Sensor (Auto A/C Model).>

• In-vehicle sensor (auto A/C model): <Ref. to AC-47, In-Vehicle Sensor (Auto A/C Model).>

AC-18

Refrigerant Pressure with Manifold Gauge Set

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)

3. Refrigerant Pressure with Manifold Gauge Set

A: PROCEDURE

1) Place the vehicle in the shade and windless condition.

2) Open the front hood.

3) Connect the manifold gauge set.

4) Open the front windows and close all doors.

5) Increase the engine to 1,500 rpm.

6) Turn the A/C switch to ON.

7) Turn the temperature control dial to MAX COOL position.

8) Turn the FRESH/RECIRC switch to RECIRC position.

9) Turn the fan speed control dial to HI (MAX) position.

10) Read the gauge.
Specification:

Low pressure: 127 — 196 kPa (1.3 — 2.0 kg/cm

2

, 18 — 28 psi)

High pressure: 1,471 — 1,667 kPa (15 — 17 kg/cm

2

, 213 — 242 psi)

Ambient temperature: 30 — 35°C (86 — 95°F)

B: INSPECTION

Symptoms

Probable cause

Repair order

High-pressure side is unusually high.

• Defective condenser fan motor
• Clogged condenser fin
• Too much refrigerant
• Air inside the system
• Defective receiver dryer (condenser)

• Replace the fan motor.
• Clean the condenser fin.
• Discharge refrigerant.
• Replace the condenser.
• After evacuating again, charge an
appropriate amount of refrigerant.

High-pressure side is unusually low.

• Defective compressor
• Not enough refrigerant
• Clogged expansion valve
• Expansion valve frozen temporarily by
moisture.

• Replace the compressor.
• Check for leaks.
• Replace the expansion valve.
• Fully evacuate the expansion valve.

Low-pressure side is unusually high.

• Defective compressor
• Defective expansion valve
• Too much refrigerant

• Replace the compressor.
• Replace the expansion valve.
• Discharge refrigerant.

Low-pressure side is unusually low.

• Not enough refrigerant
• Clogged expansion valve
• Expansion valve frozen temporarily by
moisture.
• Saturated receiver dryer (condenser)

• Check for leaks.
• Replace the expansion valve.
• Replace the condenser.