Symptoms of a Bad or Failing AC Control Module

The AC systems found on modern vehicles are sophisticated systems that can come equipped with an array of sensors and components. The AC control module is used to control and regulate all the functions of the AC system electronically. It reads data from the cabin and the outside of the vehicle and uses that information to regulate and adjust the AC system as needed to keep the cabin at the correct temperature.

As the AC control module basically controls the entire electronic side of the AC system, any problems with it can have a dramatic effect on the entire system and should be inspected. Usually when a control module has begun to fail, it will begin to show symptoms that can alert the driver of a problem.

1. Inconsistent cooling

Because the AC control module controls and regulates all of the functions of the system, you may begin to notice cooling inconsistencies when there is a problem. If the cabin temperature is unable to reach, or struggles to maintain, the correct temperature, then that may be indicative of a problem with the AC control module. Since the module is what controls the system, any inconsistencies in the behavior of the system may be attributed to the module.

2. Out-of-date software updates

The AC control module is essentially the dedicated computer for the AC system, and similar to any non-automotive computer, it may require software updates to alleviate issues that may arise over time. Due to the nature of computer programs, any issues or bugs with the control module’s software may not present themselves until later in the vehicle's service life or until after the vehicle has been on the road for a few years.

With this in mind, some manufacturers will provide software updates for their systems if they find a problem or bug with the software. Owners can find out if any updates are required for their vehicles’ computer systems by checking the latest service bulletin for your vehicle.

3. Uneven air distribution

Aside from controlling and regulating the temperature functions of the AC system, the AC module is also sometimes responsible for directing the airflow to the correct vents. If you notice that certain vents are not blowing air, then this may be a sign that the control module could possibly be having a problem. When a module is beginning to fail, air may blow only out of certain vents or under certain settings.

Since the AC control module is basically the control computer for the AC system, any problems with it will negatively affect the entire system. If you suspect that you may possibly have a problem with your AC control module, have it diagnosed by a professional technician, such as one from YourMechanic. If necessary, they will be able to replace your AC control module to help alleviate any issues with your AC.


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Ben

42 years of experience
1589 reviews
Ben
42 years of experience
Kia Soul L4-1.6L - Heating AC Inspection - Houston, Texas
Ben is the consummate professional - knowledgeable, but additionally friendly and personable. I appreciate his honesty and willingness to help.
Volkswagen Beetle - Heating AC - Houston, Texas
i am well satisfied with Mr Smith working on my car(s). He replaced the Jaguar fuel pump like an expert, and then he diagnosed the VW bug ac compressor and fixed it on the spot. I would recommend him to anyone with a car issue

Diana

19 years of experience
130 reviews
Diana
19 years of experience
Hummer H2 V8-6.0L - Heating AC - Brooklyn, New York
Diana is a pro. She made sure everything was ready beforehand, and arrived early, ready to go. She knew her stuff and took the old headers off my Hummer H2 in half the time any other mechanic quoted me. Highly recommended!
Saab 9-3 - Heating AC - Fords, New Jersey
Very professional, prompt and courteous. Knowledgeable in her trade, thorough and informative in description of diagnosis.

Peter

44 years of experience
1397 reviews
Peter
44 years of experience
Saab 9-3 L4-2.0L Turbo - Heating AC - Phoenix, Arizona
He knows what he's doing. Very polite and explained everything. I would no doubt use him again. I highly recommend him.
Mazda Miata - Heating AC - Peoria, Arizona
We are so thrilled to have found Peter as our new mechanic. He is very thorough and knowledgeable. He is also friendly, professional, and extremely honest. He explained to us exactly what services were needed on our vehicle to repair the air conditioner and provided us with an written estimate of the cost. He literally saved us thousands of dollars in repair costs. A local major competitor quoted us a repair cost of a minimum of $1,400 and said that the cost would go up to $2,400 if they discovered an additional part was required. Peter charged us only $202, plus performed the work at our home. The air conditioner in our 2004 Mazda Miata has honestly never worked so great--it always blew out warm air. We just assumed it was how that particular car was manufactured. We would highly recommend Peter to anyone who is in need of an experienced and honest mechanic.

Johnny

34 years of experience
392 reviews
Johnny
34 years of experience
Honda Accord V6-3.5L - Heating AC - Sacramento, California
Johnny showed up early to the appointment and was very thorough in his inspection. He promptly recommended the service to fix the items that are needing repairs. He was very professional and knowledgeable. I would recommend him for service.

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