Air Conditioning System Diagnosis; Insufficient Cooling Diagnosis - Daewoo MATIZ Service Manual

7B – 8 MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM

AIR CONDITIONING SYSTEM DIAGNOSIS

Step
1 Can you verify the customer complaint?
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.
2
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?
1. Turn the ignition switch OFF.
3 2. Connect the high and the low pressure gauges.
Are both pressures within the value specified?
4 Are both pressures above the specified value?
5 Are both pressures within the specified value?
6 Are both pressure below the specified value?
1. Add the refrigerant R–134a.
2. Check the A/C system for leaks.
7 3. Repair any refrigerant leaks as needed.
4. Recover, evacuate, and recharge the A/C system.
Are both pressure within the specified value?
1. Start the engine and allow it to run at idle.
2. Set the A/C controls to following positions.
D The A/C switch to the ON position.
D The fresh air control switch to fresh air.
8
D The blower motor to 4.
D The temperature to full cold.
Does the A/C compressor clutch engage?
1. Check for a knocking noise from the A/C
compressor.
2. Cycle the A/C compressor ON and OFF in order
9
to verify the source of the noise.
Do you hear a loud knocking noise?
1. Recover the A/C system refrigerant.
2. Replace the A/C compressor.
10 3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
Is the repair complete?
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
11 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?

INSUFFICIENT COOLING DIAGNOSIS

Action Value(s) Yes
– Go to Step 2
–
System OK
Low Side
Go to Step 8
Pressure:
Go to Step 5
200 kPa
Go to Step 8
(29 Psi) (29 Psi)
Go to Step 7
High Side
Pressure:
1,500 kPa
(217.5 Psi)
Go to Step 8
–
Go to Step 9
–
Go to Step 10
–
Go to Step 14
–
Go to Step 12
No
System OK
Go to Step 3
Go to Step 6
–
–
Go to Step 4
–
Go to Step 11
Go to Step 14
–
Go to Step 13
DAEWOO M-150 BL2