Hi Lou,
I have a 2014 Kia Cadenza albeit it’s a rare vehicle in Canada. The car has 200,000 kilometres on it.
I’ve had an air conditioning issue for about two years that I can’t figure out. When I start the car, the AC won’t turn on until I start driving. Likewise, if I’m stopped for more than five to 10 minutes with the engine running, the AC stops cooling the car. As soon as I start moving again, ice-cold air comes out.
Any ideas on what this could potentially be?
Thanks – James C.
The possibilities are numerous, but I have some ideas. I ‘m sorry if they seem complicated, I’m trying to keep it as simple as possible.
The first thing I would do if I was inspecting your car is to verify that the refrigerant levels are correct. A system that is even 10-20 per cent low can cause intermittent cooling problems. Once I knew the levels were correct, I would move on.
With a scan tool I would access both the Powertrain Control Module (PCM) and the climate control system, scrutinizing for any kind of air conditioning trouble codes. If there are any present, then focus on diagnosing those first.
Assuming no codes stored, I would focus on the car when cold. With the scan tool still connected, I would examine the live data for the air conditioning. I would manually toggle the vehicles air conditioning on and off using the dashboard push button or climate control. As I toggle the button, I would look to see if the PCM is seeing my button push. At the same time, I would visually look under the hood at the AC compressor to see if it is engaging when I command it to using the button push. This is hopefully going to indicate whether the problem is electrical or mechanical.
Situations like yours are often electrical and unfortunately all manners of differing vehicle sensors can cause issues. For example, an ambient air temperature sensor is typically located in the front bumper and reports to the PCM the outside air temperature. Let’s say its damaged from a collision and is falsely reporting a minus 20-degree Celsius reading when in fact it is a super hot day.
The PCM is going to turn off the air conditioning thinking it is extremely cold. Once the vehicle starts rolling down the highway, perhaps hot outside air warms the sensor and it starts functioning properly, sending a correct reading, thus allowing the air conditioning to turn on. Obviously, this is a long shot, but hopefully you get the idea, it can be complicated.
Regardless, it sounds to me like you are going to require a professional to help you out. I suspect they will follow a similar procedure.
Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about maintenance and repair? E-mail globedrive@globeandmail.com, placing “Lou’s Garage” in the subject line.
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