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Testing Your Car’s AC Pressure Sensor

If you are suspecting that your car's AC pressure sensor is faulty but you are not sure how to detect, read this article to know how to test the pressure sensor. You have surely heard about AC switches or air conditioning pressure sensors, but what are they? Your car’s AC pressure sensor turns off the air conditioning system whenever the refrigerant pressure faces extremities. This does two things- i) Signals the need for a recharge of refrigerant. ii) Saves the compressor from running without the proper lubrication. If the AC pressure switch is bypassed, it might cause the compressor to freeze up due to lack of fluid and lubrication. When it happens you might need to consider contacting a professional mechanic and ensure if the AC high-pressure switch needs a replacement. However, you can follow some simple steps and can easily check if the pressure sensor is okay or not. You might need an OBD II scanner. Onboard Diagnostics II or OBD-II is a standardized system that is used for cars and trucks for self-diagnostics. Best for those who are trying to scan the AC pressure sensor at home.


Step 1 Attach a low-pressure gauge from a refrigerant recharge kit to the low-pressure fitting which is located between the accumulator and the compressor, marked with a capital “L”. Now, check the pressure of the air conditioning system. The low-pressure gauge should measure 56 psi or higher. If the pressure is at the correct level, then there might be some issues regarding the sensor.

Step 2 Turn your car's AC on with the engine running. Open the doors of the vehicle in question, this will prevent the air conditioning from cycling off. If the air conditioning cuts off at irregular intervals, your best bet will be that the air conditioning pressure switch or sensor may not be working correctly.

Step 3 Locate the OBD II port on your vehicle, which is normally located nearby the steering column. Many cars have the OBD II port below and to the left, while other models have the port on the backside of the center. Next, plug the scanner into the port and turn on the car's ignition switch. Any sensor codes that come up on the OBD II scanner can either be read directly from the scanner. But if you face difficulty then you can look up websites or use apps. If the air conditioning pressure sensor or switch is faulty, then you’ll be informed.

Step 4 After you’ve completed step-3 remove the air conditioning pressure sensor and test the electrical connection leading to the sensor from your vehicle's electrical harness. One final thing is to touch the probes of the multimeter to the electrical harness’s end and turn the ignition key on. The multimeter should read 4.0 to 5.0 V or Volts if the sensor’s electric connection is working properly. Your AC pressure sensor’s health depends based on the reading of the OBD II, so make sure you check it well. If you have doubts or if you think the reading isn’t accurate, you can recheck to make sure. Anyway, these are a few things you need to know about testing your car’s AC pressure sensor.

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Testing Your Car AC Pressure Sensor  

PartsCargo is an online shop for OEM or aftermarket vehicle parts and accessories. PartsCargo has a huge stock of OEM and Aftermarket auto p...

Testing Your Car AC Pressure Sensor  

PartsCargo is an online shop for OEM or aftermarket vehicle parts and accessories. PartsCargo has a huge stock of OEM and Aftermarket auto p...

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