The advent of the autonomous car has highlighted the fundamental importance of having good sensors. That being said, we have long been committed to providing effective – and reliable – sensors to our customers. So whether you are looking for engine and transmission sensors, or for comfort and safety – not to mention emissions and e-mobility – you should definitely take a look at our range.
Located on the air conditioning circuit near the condenser, the air conditioning pressure sensor (also known as the air conditioning refrigerant pressure sensor) measures the pressure of the air conditioning refrigerant (pressure between 10 and 20 bars, sometimes even 30). It will send the information to the ECU, which in turn controls the air conditioning circuit – in this case, controlling the circuit means switching on or off the system’s compressor (remember, this is an essential part of the air conditioning system) and the condenser (also called the air conditioning radiator fan).
If it detects too much pressure, then the ECU will immediately stop the compressor and activate the fan to quickly cool the air conditioning fluid.
SYMPTOMS
The following symptoms are frequently associated with an air conditioning pressure sensor failure:
DIAGNOSIS PROCEDURE
Detecting a pressure sensor failure can be complicated, because even if the air conditioning system is no longer functional, the failure is not necessarily related to the pressure sensor itself. Moreover, there is not always a particular sign that the pressure sensor is to blame.
However, you need to check the air conditioning refrigerant’s level first, because if the sensor does not detect enough pressure, it will not be able to carry out its measurements. In fact, the system is no longer working due to the lack of fluid, not due to the failure of the air conditioning pressure sensor.
In case of compressor or clutch failure, you have to visually inspect the pressure sensor:
If the failure does not come from the two elements mentioned above, you will need to carry out a test to verify the correct operation of the pressure sensor. This will involve blowing compressed air inside the sensor. If you can hear a clicking sound, then it means that the pressure switch is tilting – a sign that it is working. If, on the other hand, there is no noise, the air conditioning pressure sensor is defective.
Using a multimeter, you can also shunt one of the pins of the sensor connector. This test must be carried out with the engine running. During this test, if the pressure sensor is involved, then the compressor will start to run.
If the above tests are inconclusive, your air conditioning pressure sensor needs replacing.
CAUSES OF FAILURE
It is possible that an air conditioning pressure sensor is no longer working due to:
INSTALLATION INSTRUCTIONS
To ensure a quick and efficient installation, you must refer to the following instructions:
Note: You do not need to drain and replace all the air conditioning refrigerant when changing the air conditioning pressure sensor, as there is a non-return valve to prevent this.
INSTALLATION TIPS
As the air conditioning pressure sensor is essential to the correct operation of the engine, it is important to follow a certain number of recommendations when replacing it:
PREVENTIVE INFORMATION
The above items are provided for information purposes only. They do not replace the advice of a qualified technician or mechanic. We strongly recommend that you consult a professional if you are unsure of what to do. Otherwise, we cannot accept responsibility for any damage to your vehicle.
When an air conditioning pressure sensor is faulty, you will quickly notice a malfunction in the vehicle’s defogging system in cool weather. This is because the ECU does not have the information and cannot tell the system what to do. In addition, your air conditioning will no longer work, and therefore poor air cooling will be felt in the passenger compartment.
Detecting a pressure sensor failure can be complicated, because even if the air conditioning system is no longer functional, the failure is not necessarily related to the pressure sensor itself. Moreover, there are not always clear signs that the problem comes from the pressure sensor.
However, you need to check the air conditioning refrigerant’s level first, because if the sensor does not detect enough pressure, it will not be able to carry out its measurements. In fact, the system is no longer working due to the lack of fluid, not due to the failure of the air conditioning pressure sensor.
In case of compressor or clutch failure, you have to visually inspect the sensor itself. You must ensure that it is not damaged or dirty.
If the failure does not come from the two elements mentioned above, you will need to carry out a test to verify the correct operation of the pressure sensor. This will involve blowing compressed air inside the sensor. If you can hear a clicking sound, then it means that the pressure sensor is tilting – a sign that it is working. If, on the other hand, there is no noise, the air conditioning pressure sensor is defective.
Using a multimeter, you can also shunt one of the pins of the sensor connector. This test must be carried out with the engine running. During this test, if the pressure sensor is involved, then the compressor will start to run.
If the above tests are inconclusive, your air conditioning pressure sensor needs replacing.
Although automotive sensors meet very strict standards, they are not eternal and there are several things that may require replacement, including a coolant fault or deterioration of the connectors that may occur due to excessive vibration from the vehicle.
We recommend the following steps to replace your air conditioning pressure sensor as efficiently as possible and to limit possible mistakes:
Note: You do not need to purge and replace all the air conditioning fluid when changing the air conditioning pressure sensor, as there is a non-return valve to prevent draining.
As a sensor specialist, we recommend the following to extend your air conditioning pressure sensor’s durability:
