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Test Description

WARNING: This page is about a different car, the 2005 Suzuki Reno and 2005 Suzuki Forenza. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to steps on the diagnostic table.

(13) See the Important below.

(32) See the Important below.

NOTE: Perform this test under garage conditions with the air temperature at 21-32°C (70-90°F), and no sun load. Follow this test carefully for accurate results.
NOTE: Perform this test exactly as described to obtain accurate results.
DIAGNOSIS PRESSURE - INSUFFICIENT COOLING

Step Action Value(s) Yes No
1 Record the customer's complaint.
Can you verify the customer's complaint?		 - Go to Step 2 System OK
2
  1. Check the A/C fuse.
  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 airflow.
  6. Check the clutch coil connection.
  7. Repair or replace any components as needed.
  8. Check the discharge air temperature with the A/C turned ON.
Is the discharge air temperature normal?		 At least 7°C (12°F) below ambient air temperature System OK Go to Step 3
3
  1. Turn the ignition switch to LOCK.
  2. Connect the high- and the low-pressure gauges.
Are both pressures within the value specified?		 69-345 kPa (10-50 psi) Go to Step 4 Go to Step 5
4
  1. Check the A/C system for leaks.
  2. Repair any refrigerant leaks as needed.
  3. Recover, evacuate, and recharge the A/C system.
  4. Observe the two pressure gauges.
Are both pressures above the value specified?		 345 kPa (50 psi) Go to Step 7 -
5 Observe the two pressure gauges.
Are both pressures below the value specified?		 69kPa (10 psi) Go to Step 6 Go to Step 7
6
  1. Add 0.45 kg (1 pound) of 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.
  5. Observe the two pressure gauges.
Are both pressures above the value specified?		 345 kPa (50 psi) Go to Step 7 -
7
  1. Start the engine and allow it to run at idle.
  2. Set the A/C controls to the following positions:
    • The A/C switch to the ON.
    • The fresh air control switch to fresh air (indicator lamp OFF).
    • The blower motor to 4.
    • The temperature to full cold.
Does the A/C compressor clutch engage?		 - Go to Step 8 Go to Step 10
8
  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 9 Go to Step 13
9
  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 compressor running normally?		 - Go to Step 13 -
10
  1. Turn the ignition switch to LOCK.
  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 11 Go to Step 12
11 Repair the electrical circuit to the A/C compressor clutch coil.
Does the A/C clutch engage?		 - Go to Step 8 -
12 Replace the A/C compressor clutch coil.
Does the A/C clutch engage?		 - Go to Step 8 -
13
  1. Close all of the vehicle's windows and doors.
  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 allow 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 15 Go to Step 14
14
  1. Turn the ignition switch to LOCK.
  2. Recover the A/C system refrigerant.
  3. Examine the high-pressure pipe for an obstruction.
  4. Examine the expansion valve for an obstruction or a malfunction.
  5. Repair the obstruction or replace the expansion valve as needed.
  6. Evacuate and recharge the A/C system.
  7. Check the A/C system for leaks.
  8. Note the discharge air temperature with the A/C ON.
Is the discharge temperature normal?		 At least 7°C (12°F) below ambient air temperature Go to Step 15 Go to Step 13
15
  1. Record the low- and the high-side pressures after the A/C system has been operating for 5 minutes or more with the engine cooling fan ON.
  2. Locate the intersection of the low- and the high side pressures. Refer to "LOW AND HIGH SIDE PRESSURE RELATIONSHIP CHART :".
Do the low- and the high-side pressures intersect in the white area of the chart?		 - System OK Go to Step 16
16 Check the high- and the low-side pressures.
Do the low- and the high-side pressures intersect in the grey area of the chart?		 - Go to Step 17 Go to Step 20
17 Feel the liquid pipe between the condenser and the expansion valve. Is the pipe cold? - Go to Step 18 Go to Step 19
18
  1. Examine the condenser for any restriction of the airflow.
  2. Check the cooling fans for proper operation.
  3. Remove the restriction or repair the fans, as required.
Is the pipe temperature normal now?		 At least 7°C (12°F) below ambient air temperature Go to Step 13 -
19
  1. Recover, evacuate, and recharge the A/C system.
  2. Check the A/C system for leaks.
Is the system free from leaks?		 - Go to Step 13 -
20 Observe the readings on the pressure gauges.
Are the A/C compressor high- and the low-side pressures within the specified value of each other?		 207 kPa (30 psi) Go to Step 21 Go to Step 26
21
  1. Run the engine at 3,000 rpm.
  2. Set the A/C controls to the following positions:
    • The A/C switch to the ON.
    • The fresh air control switch to fresh air.
    • The blower motor to 4.
    • The temperature to full cold.
  3. Close all of the vehicle's windows and doors.
  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?		 207 kPa (30 psi) Go to Step 22 Go to Step 13
22 Observe the pressure rise on both gauges and the temperatures of both the compressor suction pipe and the discharge pipe.
Is the pressure rise on both gauges slow and the suction pipe warm with the discharge pipe very hot?		 - Go to Step 25 Go to Step 23
23
  1. Turn the ignition switch to LOCK.
  2. Make sure the compressor clutch is disengaged.
  3. Attempt to turn the clutch driver (not the pulley).
Can you turn the clutch driver freely by hand?		 - Go to Step 25 Go to Step 24
24
  1. Start the engine.
  2. Observe the low-side pressure gauge while running the engine between 3,000 and 3,800 rpm.
Does the low-side pressure rise rapidly?		 - Go to Step 32 Go to Step 25
25
  1. Recover the A/C system refrigerant.
  2. Replace the A/C compressor.
  3. Evacuate and recharge the A/C system.
Is the compressor functioning normally?		 - Go to Step 13 -
26 Check the low-side pressure.
Is the low-side pressure within the specified value?		 172-241 kPa (25-35 psi) Go to Step 27 Go to Step 32
27 Feel the high-side pipe leading up to the expansion valve connecting block.
Is the pipe cold before the connecting block?		 - Go to Step 28 Go to Step 29
28
  1. Check for a restriction in the high-side pipe before the expansion valve.
  2. Repair or replace the high-side pipe.
Is the pipe performing normally?		 - Go to Step 13 -
29 Add the specified amount of refrigerant to the A/C system.
Does the cooling performance improve?		 0.40 kg (14 ounces) Go to Step 30 Go to Step 31
30
  1. Check the A/C system for leaks.
  2. Repair any refrigerant leaks, as needed.
  3. Evacuate and recharge the A/C system.
  4. Check the A/C system for leaks.
Is the system free from leaks?		 - Go to Step 13 -
31
  1. Recover the refrigerant.
  2. Check the expansion valve for obstructions.
  3. Repair or replace the expansion valve, as required.
  4. Evacuate and recharge the system.
  5. Check the A/C system for leaks.
Is the system free from leaks?		 - Go to Step 13 -
32
  1. Run the engine for 5 minutes at 2,000 rpm.
  2. Set the A/C controls to the following positions:
    • The A/C switch to the ON position.
    • The fresh air control switch to recirculate (indicator lamp ON).
    • The blower motor to 1.
    • The temperature to full cold.
  3. Close all of the vehicle's windows and doors.
  4. Open the vehicle hood.
Is the low-side pressure within the specified value?		 172-241 kPa (25-35 psi) Go to Step 13 Go to Step 33
33
  1. Recover the A/C system refrigerant.
  2. Replace the A/C compressor control valve.
  3. Evacuate and recharge the A/C system.
  4. Check the A/C system for leaks.
Is the system free from leaks?		 - Go to Step 13 -
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