Step
| Action
| Values
| Yes
| No
|
1
| Can you verify the customer complaint?
| --
| Go to
Step 2
| System OK
|
2
|
- Inspect the fuses Ef14, Ef19, and Ef12.
- Inspect the blower fan operation.
- Inspect the engine cooling fan operation.
- Inspect the A/C compressor belt.
- Inspect the A/C condenser for restricted air flow.
- Inspect the slippage of the compressor clutch.
- Repair or replace any components as needed.
- Inspect the A/C system operation.
Is the A/C system operation normal?
| --
| System OK
|
Step 3
|
3
|
- Turn the ignition switch OFF.
- Connect the high and the low pressure gages.
Are both pressures within the value specified?
| Low Side Pressure: 200 kPa (29 psi)
High Side Pressure: 1,500 kPa (217.5 psi)
| Go to
Step 8
| Go to
Step 6
|
4
| Are both pressures above the specified value?
| Low Side Pressure: 200 kPa (29 psi)
High Side Pressure: 1,500 kPa (217.5 psi)
| Go to
Step 5
| --
|
5
| Are both pressures within the specified value?
| Low Side Pressure: 200 kPa (29 psi)
High Side Pressure: 1,500 kPa (217.5 psi)
| Go to
Step 8
| --
|
6
| Are both pressures below the specified value?
| Low Side Pressure: 200 kPa (29 psi)
High Side Pressure: 1,500 kPa (217.5 psi)
| Go to
Step 7
| Go to
Step 4
|
7
|
- Add the refrigerant R-134a.
- Inspect the A/C system for leaks.
- Repair any refrigerant leaks as needed.
- Recover, evacuate, and recharge the A/C system.
Are both pressures within the specified value?
| Low Side Pressure: 200 kPa (29 psi)
High Side Pressure: 1,500 kPa (217.5 psi)
| Go to
Step 8
| --
|
8
|
- Start the engine and allow it to run at idle.
- 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 temperature to full cold |
Does the A/C compressor clutch engage?
| --
| Go to
Step 9
| Go to
Step 11
|
9
|
- Inspect for a knocking noise from the A/C compressor.
- 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 10
| Go to
Step 14
|
10
|
- Recover the A/C system refrigerant.
- Replace the A/C compressor.
- Evacuate and recharge the A/C system.
- Inspect the A/C system for leaks.
Is the repair complete?
| --
| Go to
Step 14
| --
|
11
|
- Turn the ignition switch OFF.
- Disconnect the A/C compressor clutch coil connector.
- Connect a jumper wire from ground to one A/C compressor clutch coil terminal.
- 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 12
| Go to
Step 13
|
12
| Repair the electrical circuit to the A/C compressor clutch coil.
Does the A/C clutch engage?
| --
| Go to
Step 20
| Go to
Step 13
|
13
| Replace the A/C compressor clutch coil.
Does the A/C clutch engage?
| --
| Go to
Step 9
| Go to
Step 10
|
14
|
Important: Perform this test under garage conditions,
21-32°C (70-90°F), and no sun load. Follow this test carefully
for accurate results.
- Close all of the windows and the doors of the vehicle.
- 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 temperature to full cold |
- Start the engine and follow it to run at idle for 5 minutes.
- 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 16
| Go to
Step 15
|
15
|
- Recover the A/C system refrigerant.
- Replace the expansion valve as needed.
- Evacuate and recharge the A/C system.
- Inspect the A/C system for leaks.
- Note the discharge air temperature with the A/C ON.
Is the discharge temperature normal?
| --
| Go to
Step 16
| Go to
Step 18
|
16
| Feel the liquid pipe between the condenser and the expansion valve.
Is the pipe cold?
| --
| Go to
Step 19
| Go to
Step 17
|
17
|
- Remove the restriction of the high pressure side.
- Inspect the A/C system for leaks.
Is the repair complete?
| --
| System OK
| --
|
18
|
- Recover the A/C system refrigerant.
- Evacuate and recharge the A/C system.
- Inspect the A/C system for leaks.
Is the repair complete?
| --
| System OK
| --
|
19
|
- Run the engine at 3,000 RPM.
- Close all of the windows and doors of the vehicle.
- 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 temperature to full cold |
- 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 OK
| Go to
Step 22
|
20
|
- Turn the ignition switch OFF.
- Turn the A/C switch to the OFF position.
- Attempt to turn the clutch driver, not the pulley.
Can you turn the clutch driver freely by hand?
| --
| Go to
Step 23
| Go to
Step 21
|
21
|
- Recover the A/C system refrigerant.
- Replace the A/C compressor.
- Evacuate and recharge the A/C system.
Is the repair complete?
| --
| System OK
| --
|
22
| Add the refrigerant R-134a.
Does the cooling performance improve?
| --
| System OK
| Go to
Step 23
|
23
|
- Recover the A/C system refrigerant.
- Replace the compressor.
- Evacuate and recharge the A/C system.
- Inspect the A/C system for leaks.
Is the repair complete?
| --
| System OK
| --
|