Audi Air Conditioner AC Recharge Instructions  A1 A3 A4 A5 A6 A7 Q3 Q5 Q7 TT

Audi Air Conditioner AC Recharge Instructions

Last Updated on Monday Mar 19, 2018

In this guide, you will find instructions on how to charge the A/C system on Audi vehicles. If your A/C is blowing hot air, there is a chance that the system is low on freon and the system needs to be refilled. In this guide, you will find instructions on how to recharge Audi A/C system in various models including A1 A3 A4 A5 A6 A7 Q3 Q5 Q7 TT. 


The most common symptom that your Audi is low on refrigerant is that hot air blows even when the temperature is set to cold.

What you will need


Step 1: Park Vehicle

Park your Audi in a safe area. Turn off the engine.

Step 2: Open hood

To add freon (R134a) to any Audi, you need to open the hood of your car. The hood release is located under the dashboard on the driver's side.

Step 3: Locate A/C port

location of a/c low pressure port on Audi A S Q TT models  3rd

Locate the low-pressure port. This picture shows the A/C charging port is on an Audi A4.

audi location of ac charging port

Note that there also is a high-pressure line. Don't use that line. The A/C charging kit connector will not fit on the port for the high-pressure line. The A/C kit only fits on the low-pressure port.

Step 4: Remove cap

diy ac recharge mamo allyr

Remove the cap from the low-pressure port of your Audi.

Step 5: Connect recharge kit

 Audi A S Q TT models  ac recharge diy video allmo allyr

Connect your A/C hose to the charging port.Get ready to add freon to your Audi A/C system.

Step 6: Start Engine

how to charge the ac on Audi A S Q TT models

Start the engine and let it idle.

Step 7: Turn A/C on

Before you can start adding refrigerant you need to turn A/C on and set it to max cold setting. Once you start the engine you are ready to add refrigerant to your Audi air conditioner system.

Step 8: Charge

Follow the instructions as directed on your particular A/C recharge kit. As you charge the system stop pressing the trigger every couple of minutes to obtain a pressure reading.   Continue adding refrigerant until your gauge reaches in the charged range. Do not allow the system to overcharge. 

 Important Notes

  • Keep the can upright and rotate it between 1 and 2 o’clock as you charge the a/c. 
  • If your vehicle uses a clutchless compressor also known as variable displacement compressor, the clutch will always look as being engaged. 
  • Do not overfill your system with freon. 
  • Do not turn the can upside when you charge the A/C. It can introduce liquid refrigerant to a/c system which can cause the locking up the a/c compressor.
  • Always follow the instructions that are provided with your specific kit.
  • It is normal for the gauge to point in the high range when the engine is turned off.

Frequently Asked Questions

The most common problem is vent actuator in vehicles with dual zone A/C. They can get stuck in one position and do not switch when you change the temperature. In vehicles that use duo-valves they can also get stuck in which case half of the car blows hot air and the other blows cold air.

The cooling fan for the condenser may not be working.

The blower fan may be defective.

AC may be low on freon. Also check low-pressure switch. If defective it can prevent the compressor from operating.

Related Videos