2003 DAEWOO MATIZ heating system

7B–2 MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
SYSTEM COMPONENTS
–FUNCTIONAL
Compressor
All compressors are belt–driven from the engine crank-
shaft through the compressor clutch pulley. The com-
pressor pulley rotates without driving the compressor
shaft until on electromagnetic clutch coils energized.
When voltage is applied to energize the clutch coil, the
clutch plate and hub assembly are drawn toward the
pulley. The magnetic force locks the clutch plate and
pulley together as one unit to drive the compressor
shaft.
Condenser Core
The condenser assembly in front of the radiator consists
of coils which carry the refrigerant and cooling fins that
provide the rapid transfer of heat. The air passing
through the condenser cools the high–pressure refriger-
ant vapor and cause it to condense into a liquid.
Expansion Valve
The expansion valve is located on the passenger
compartment side of the dash panel. The expansion
valve can fail in three different positions: open, closed,
or restricted. An expansion valve that fails in the open
position will result in a noisy A/C compressor or no cool-
ing. The cause can be a broken spring, a broken ball, or
excessive moisture in the A/C system. If the spring or
the ball is found to be detective, replace the expansion
valve. If excessive moisture is found in the A/C system,
recycle the refrigerant. An expansion valve that fails in
the closed position will result in low suction pressure and
no cooling. This may be caused by a failed power done
or excessive moisture in the A/C system. If the power
dome on the expansion valve is found to be defective,
replace the expansion valve. If excessive moisture is
found in the A/C system, recycle the refrigerant.
A restricted expansion valve will result in low suction
pressure and no cooling. This may be caused by debrisin the refrigerant system. If debris is believed to be
cause, recycle the refrigerant, replace the expansion
valve, and replace the receiver/dryer.
Evaporator Core
The evaporator is device which cools and dehumidifies
the air before it enters the vehicle. High–pressure liquid
refrigerant flows through the expansion tube (orifice)
and becomes a low–pressure gas in the evaporator. The
heat in the air passing through the evaporator core is
transferred to the cooler surface of the core, which cools
the air. As the process of heat transfer from the air to the
evaporator core surface is taking place, any moisture
(humidity) in the air condenses on the outside surface of
the evaporator core and is drained off as water.
Receiver–Dryer
The sealed receiver–dryer assembly is connected to the
evaporator outlet pipe. It acts as a refrigerant storing
container, receiving liquid and some vapor and refriger-
ant oil from the evaporator.
At the bottom the receiver–dryer is the desiccant, which
acts as a drying agent for the moisture that may have
entered the system. The receiver–dryer is serviceable
only as an assembly.
Dual Cut Switch
The dual cut switch controls compressor operation when
the cycling refrigerant pressure is dropped or surged.
Evaporator Thermistor
A semiconductor which resistance is noticeably changed
as the change of temperature. When the refrigerant tem-
perature of the evaporator drops to 0
C (32
F) and be-
low, the evaporator cores get stuck with frost or ice,
reducing the airflow, lowering the cooling capacity. The
thermistor is a sensor which is used to prevent from frost-
ing or icing.
The thermistor is installed on the evaporator.

MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM 7B–3
DAEWOO M-150 BL2
COMPONENT LOCATOR
A/C SYSTEM
(Left–Hand Drive Shown, Right–Hand Drive Similar)
D18B401B

7B–4 MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO M-150 BL2
1. High Pressure Pipe
(Receiver Dryer→Evaporator)
2. Low Pressure Hose
(Evaporator→Compressor)
3. O–ring
4. Evaporator Module
5. Evaporator Upper Case
6. thermistor
7. Evaporator Core
8. Expansion Valve
9. Evaporator Inlet Pipe
10. Plate
11. Evaporator Lower Case
12. O–ring
13. High Pressure Pipe
(Compressor→Condenser)14. Compressor
15. Compressor Magnetic Clutch
16. Compressor Pulley
17. Compressor Clutch Drive
18. Shaft Bolt
19. High Pressure Pipe
(Condenser→Receiver–Dryer)
20. Condenser
21. Receiver–Dryer
22. Dual Cut Switch
23. Receiver–Dryer Bracket
24. Compressor Bracket
25. Compressor Stay
26. A/C & Power Steering Bracket

MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM 7B–5
DAEWOO M-150 BL2
DIAGNOSTIC INFORMATION AND PROCEDURES
GENERAL DIAGNOSIS
TESTING THE REFRIGERANT
SYSTEM
If you suspect a problem in the refrigerant system,
check for the following conditions:
1. Check the outer surfaces of the radiator and the con-
denser cores to be sure that the airflow is not blocked
by dirt, leaves, or other foreign material. Check be-
tween the condenser and the radiator, as well as all
outer surfaces.
2. Check for restrictions or kinks in the condenser core,
the hoses, and the tubes.
3. Check the operation of the blower fan.
4. Check all the air ducts for leaks or restrictions. A low
airflow rate may indicate a restricted evaporator core.
5. Check for slippage of the compressor clutch.
6. Check the drive belt tension.
INSUFFICIENT COOLING “QUICK
CHECK” PROCEDURE
Perform the following “hand-feel” procedure to get a
quick idea of whether the air conditioning (A/C) system
has the proper charge of Refrigerant-134a.
1. Warm up the engine. Run the engine at idle.
2. Open the hood and all the doors.
3. Turn the A/C switch ON.
4. Set the temperature control to the full cold position.
5. Set the blower speed switch on 4.
6.“Hand-feel” the temperature of the evaporator outlet
pipe. The pipe should be cold.
7. Check for other problems. Refer to “Testing the Re-
frigerant System” in this section.
8. Leak check the system. Refer to “Leak Testing the
Refrigerant System” in this section. If you find a leak,
discharge the system and repair the leak as required.
After completing the repair, evacuate and charge the
system.
9. If there is no leak, refer to “Insufficient Cooling Diag-
nosis” in this section.

7B–6 MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO M-150 BL2
PRESSURE-TEMPERATURE RELATIONSHIP OF R-134A


TEMPERATURE

C (
F)*

PRESSURE
kPa (psig)*

TEMPERATURE

C (
F)*

PRESSURE
kPa (psig)*
–8.89 (16) 105.70 (15.33) 37.78 (100) 856.84 (124.27)
–7.78 (18) 114.87 (16.66) 38.89 (102) 886.56 (128.58)
–6.67 (20) 124.32 (18.03) 40.00 (104) 916.35 (132.98)
–5.56 (22) 134.11 (19.45) 41.11 (106) 947.92 (137.48)
–4.44 (24) 144.24 (20.92) 42.22 (108) 979.64 (142.08) –3.33 (26) 154.65 (22.43) 43.33 (110) 1012.11 (146.79) –2.22 (28) 165.48 (24.00) 44.44 (112) 1045.21 (151.59)
–1.11 (30)

176.65 (25.62)

45.56 (114)

1079.14 (156.51)
0.00 (32) 188.16 (27.29) 46.67 (116) 1113.75 (161.53)
1.11 (34) 200.02 (29.01) 47.78 (118) 1149.12 (166.66)
2.22 (36) 212.30 (30.79) 48.89 (120) 1185.18 (171.89)
3.33 (38) 224.98 (32.63) 50.00 (122) 1222.07 (177.24)
4.44 (40) 238.08 (34.53) 51.11 (124) 1259.72 (182.70)
7.22 (45) 272.49 (39.52) 52.22 (126) 1298.12 (188.27)
10.00 (50) 309.58 (44.90) 53.33 (128) 1337.35 (193.96) 12.77 (55) 349.51 (50.69) 54.44 (130) 1377.35 (199.76) 15.56 (60) 392.33 (56.90) 57.22 (135) 1480.91 (214.78)
18.33 (65)

438.18 (63.55)

60.00 (140)

1589.57 (230.54)
21.11 (70) 487.27 (70.67) 62.78 (145) 1703.62 (247.08)
23.89 (75) 539.67 (78.27) 65.56 (150) 1823.04 (264.40)
26.67 (80) 609.38 (88.38) 68.33 (155) 1948.04 (282.53)
29.44 (85) 655.09 (95.01) 71.11 (160) 2078.77 (301.49)
32.22 (90) 718.39 (104.19) 73.89 (165) 2215.29 (321.29)
35.00 (95) 785.61 (113.94) 76.67 (170) 2357.81 (341.96)
* All values rounded to two decimal places.
EVAPORATOR RANGE: From –6.67 to 7.22
C (20 to 45
F), the temperatures represent the gas temperatures inside
the coil and not on the coil surfaces. Add 1.67 to 5.56
C (3 to 10
F) the temperature for coil and air-off temperatures.
CONDENSER RANGE: From 110 to 160
F, temperatures are not ambient. Add 19.4 to 22.2
C (35 to 40
F) for proper
heat transfer, then refer to the pressure chart.
Example: 32
C (90
F) ambient temperature
+22

C (40
F)
54
C (130
F)
Condenser temperature = 1379 kPa (200 psig)
Based on 48.3 km/h (30 mph) air flow.

MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM 7B–7
DAEWOO M-150 BL2
LEAK TESTING THE REFRIGERANT
SYSTEM
Test for leaks whenever you suspect a refrigerant leak in
the system. You should also test for leaks whenever you
perform a service operation which results in disturbing
the lines or the connections. Leaks are commonly found
at the refrigerant fittings or at the connections. Leaks are
commonly caused by the following problems:
Improper torque.
Damaged O-ring seals.
Dirt or lint on the O-ring seals.
Liquid Leak Detectors
Use a liquid leak detector solution on locations such as
fittings. Apply the solution to the area in question with
the swab that is supplied with the solution. Look for
bubbles to appear. This will indicate the existence and
location of any leak.
For areas where this is not practical, such as sections of
the evaporator and the condenser, an electronic leak de-
tector is more useful.
Electronic Leak Detectors
Follow the manufacturer’s instructions for calibration,
operation, and maintenance of an electronic leak detec-
tor. Battery condition is especially important to the accu-
racy of a portable model. Set the detector to R-134a
before beginning the test.
Important: Electronic leak detectors are sensitive to
windshield washing solutions, solvents and cleaners,
and certain vehicle adhesives.
Surfaces must be clean to prevent false readings. Make
sure that all surfaces are dry to prevent damage to the
detector.
General Testing Instructions
Follow the entire path of the refrigerant system.
Completely circle each joint at 25 to 50 mm (1 to 2
inches) per second.
Hold the probe tip within 6 mm (1/4 inch) of the sur-
face.
Do not block the air intake.The audible tone changes from 1 to 2 clicks per second
into a solid alarm if there is a leak. Adjust the balance
control to maintain 1 to 2 clicks per second.
Test all of the following areas, even after one leak has
been confirmed:
Evaporator inlet and outlet.
Receiver-drier inlet and outlet.
Condenser inlet and outlet.
Brazed and welded areas.
Damaged areas.
Hose couplings.
Compressor rear head.
All fittings and joints.
Testing Service Ports/Access Valves
The sealing cap is the primary seal for the service ports.
This cap contains a special leak-free O-ring. Make sure
that this cap is not missing or loose. Always use the cor-
rect cap.
Testing the Evaporator Core
Leaks in the evaporator core are difficult to find. Test the
evaporator core using the following procedure:
1. Run the blower fan at speed setting 4 for at least
15 minutes.
2. Turn the blower to the OFF position.
3. Wait for 10 minutes.
4. Remove the blower motor resistor. Refer to “Blower
Motor Resistor” in this section.
5. Insert the leak detector probe as close as possible to
the evaporator core. The detector will indicate a leak
with a solid alarm.
6. Use a flashlight to search for refrigerant oil in the core
surface.
Testing the Compressor Shaft Seal
1. Blow shop air behind and in front of the compressor
clutch/pulley for at least 15 seconds.
2. Wait 1 to 2 minutes.
3. Probe the area in front of the pulley. If the detector
emits a solid alarm, there is a leak.

7B–8 MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO M-150 BL2
AIR CONDITIONING SYSTEM DIAGNOSIS
INSUFFICIENT COOLING DIAGNOSIS
Step Action Value(s) Yes No
1Can you verify the customer complaint?–Go to Step 2System OK
2
1. Check the fuses Ef14, Ef19, and Ef12.
2. Check the blower fan operation.
3. Check the engine cooling fan operation.
4. Check the A/C compressor belt.
5. Check the A/C condenser for restricted air flow.
6. Check the slippage of the compressor clutch.
7. Repair or replace any components as needed.
8. Check the A/C system operation.
Is the A/C system operation normal?
–
System OKGo to Step 3
3
1. Turn the ignition switch OFF.
2. Connect the high and the low pressure gauges.
Are both pressures within the value specified?
Low SideGo to Step 8Go to Step 6
4Are both pressures above the specified value?Pressure:Go to Step 5–
5Are both pressures within the specified value?200 kPa
(29 Psi)Go to Step 8–
6Are both pressure below the specified value?
(29 Psi)
Go to Step 7Go to Step 4
7
1. Add the refrigerant R–134a.
2. Check the A/C system for leaks.
3. Repair any refrigerant leaks as needed.
4. Recover, evacuate, and recharge the A/C system.
Are both pressure within the specified value?High Side
Pressure:
1,500 kPa
(217.5 Psi)
Go to Step 8
–
8
1. Start the engine and allow it to run at idle.
2. Set the A/C controls to following positions.
The A/C switch to the ON position.
The fresh air control switch to fresh air.
The blower motor to 4.
The temperature to full cold.
Does the A/C compressor clutch engage?
–
Go to Step 9Go to Step 11
9
1. Check for a knocking noise from the A/C
compressor.
2. Cycle the A/C compressor ON and OFF in order
to verify the source of the noise.
Do you hear a loud knocking noise?
–
Go to Step 10Go to Step 14
10
1. Recover the A/C system refrigerant.
2. Replace the A/C compressor.
3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
Is the repair complete?
–
Go to Step 14
–
11
1. Turn the ignition switch OFF.
2. Disconnect the A/C compressor clutch coil
connector.
3. Connect a jumper wire from ground to one A/C
compressor clutch coil terminal.
4. Connect a fused jumper wire from the positive
battery terminal to the other A/C compressor
clutch coil terminal.
Does the A/C clutch engage?
–
Go to Step 12Go to Step 13

MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM 7B–9
DAEWOO M-150 BL2
Insufficient Cooling Diagnosis (Cont’d)
Step Action Value(s) Yes No
12
Repair the electrical circuit to the A/C compressor
clutch coil.
Does the A/C clutch engage?
–
Go to Step 20Go to Step 13
13Replace the A/C compressor clutch coil.
Does the A/C clutch engage?–Go to Step 9Go to Step 10
14
Important: Perform this test under garage condi-
tions; 21-32
C (70-90
F) and no sun load. Follow
this test carefully for accurate results.
1. Close all of the windows and the doors of the
vehicle.
2. Set the A/C controls to the following positions:
The A/C switch to the ON position.
The fresh air control switch to fresh air.
The blower motor to 4.
The temperature to full cold.
3. Start the engine and follow it to run at idle for
5 minutes.
4. Feel the evaporator inlet and outlet pipes.
Is there a noticeable difference in the temperature of
the evaporator inlet and outlet pipes?
–
Go to Step 16Go to Step 15
15
1. Recover the A/C system refrigerant.
2. Replace the expansion valve as needed.
3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
5. Note the discharge air temperature with the A/C
ON.
Is the discharge temperature normal?
–
Go to Step16Go to Step 18
16
Feel the liquid pipe between the condenser and the
expansion valve.
Is the pipe cold?
–
Go to Step 19Go to Step 17
17
1. Remove the restriction of the high pressure side.
2. Check the A/C system for leaks.
Is the repair complete?
–
System OK
–
18
1. Recover the A/C system refrigerant.
2. Evacuate and recharge the A/C system.
3. Check the A/C system for leaks.
Is the repair complete?
–
System OK
–
19
1. Run the engine at 3,000 rpm.
2. Close all of the windows and doors of the vehicle.
3. Set the A/C controls to the following positions:
The A/C switch to the ON position.
The fresh air control switch to fresh air.
The blower motor to 4.
The temperature to full cold.
4. Turn the A/C switch ON and OFF every
20 seconds for 3 minutes.
Are the A/C compressor high and the low side
pressures within the specified value of each other?
Low Side
Pressure:
200 kPa
(29 psi)
High Side
Pressure:
1,500 kPa
(217.5 psi)
System OKGo to Step 22