We purchased our 2012 Legacy 2.5i premium with moon roof and all weather package in January 2012. After much research we determined it would be a great fit for our family. As soon as it began to get warm outside however, we quickly realized there seemed to be a problem with A/C. Upon start up the vent air registers 40 degrees on max cool recirculate. After about 5 minutes of running the air temperature begins to rise gradually until the the vent temperature is 60 degrees. The air is not only uncomfortably warm but also begins to feel humid. The kicker is that the vent air 60 degrees even though the ambient air temperature outside is between 70 and 75 degrees. You will get hot in this car running the air if the temp outside is anywhere from 65-85 degrees. I suspected there was a faulty sensor somewhere which would cause the system to shut off. (This is a clutch-less compressor, so the "wobble" plate on the compressor was going into bypass mode, not cooling)
I had it in the dealership three times for this problem. The first time they said there was no problem and it was working fine. They failed to actually drive it down the road to diagnose, so I requested a more extensive look at the ac system.
The second time they stated the system was overcharged and put a correct charge in it. Now for the first five minutes of operation the vent air is 42 degrees and not 40. Obviously that didn't help.
The third time was at a different dealer as there was no resolution from the first and we seemed to be going backwards. Finally a skilled technician took the time to research and get to the bottom of the matter. I received a phone call and they wanted me to go on a test drive with the tech and his laptop plugged in to the car. I did so. On the laptop he showed me a value called the evaporator temperature target. The is a number controlled directly by the computer that tells the car how cold to make the air coming out of the vents. We went for a drive. At around five minutes, that value slowly begins to rise until the target temperature set by the computer is almost 20 degrees higher. That explained why the air temperature consistently rises from 40 to 60 degrees under the conditions I already mentioned. The only way to reset the value and get the air cold again is to turn the A/C off then back on. It cools back down for five minutes and starts to go back up again.
Interestingly enough the tech said he never encountered this problem before and kicked it up the ladder to the Subie engineers. Turns out it wasn't a faulty control head or sensor, but it was doing exactly what they designed it to do. To kick the compressor off as much as possible to improve fuel economy.
Problem is, if I want to get better fuel economy by not running the air, I'll turn it off. If I'm hot, I want the air to be cold. We drove an identical Legacy on the lot and it performed exactly the same. If you spend the extra money and upgrade to a limited model with auto climate control, it blows 40 degree air non-stop. Evidently it operates differently than the manual controls because it has in cabin temperature sensor that regulates when the compressor shuts of or enters by-pass mode.
Oddly enough, when it gets really hot (90 plus degrees) the system seems to work well. If you want cold air March-May you are out of luck.
If you want to spend 20+ thousand dollars on a new car and expect the A/C to keep you cold, I suggest you keep driving past the Subaru dealership.
A D V E R T I S E M E N T S
We purchased our 2012 Legacy 2.5i premium with moon roof and all weather package in January 2012. After much research we determined it would be a great fit for our family. As soon as it began to get warm outside however, we quickly realized there seemed to be a problem with A/C. Upon start up the vent air registers 40 degrees on max cool recirculate. After about 5 minutes of running the air temperature begins to rise gradually until the the vent temperature is 60 degrees. The air is not only uncomfortably warm but also begins to feel humid. The kicker is that the vent air 60 degrees even though the ambient air temperature outside is between 70 and 75 degrees. You will get hot in this car running the air if the temp outside is anywhere from 65-85 degrees. I suspected there was a faulty sensor somewhere which would cause the system to shut off. (This is a clutch-less compressor, so the "wobble" plate on the compressor was going into bypass mode, not cooling)
I had it in the dealership three times for this problem. The first time they said there was no problem and it was working fine. They failed to actually drive it down the road to diagnose, so I requested a more extensive look at the ac system.
The second time they stated the system was overcharged and put a correct charge in it. Now for the first five minutes of operation the vent air is 42 degrees and not 40. Obviously that didn't help.
The third time was at a different dealer as there was no resolution from the first and we seemed to be going backwards. Finally a skilled technician took the time to research and get to the bottom of the matter. I received a phone call and they wanted me to go on a test drive with the tech and his laptop plugged in to the car. I did so. On the laptop he showed me a value called the evaporator temperature target. The is a number controlled directly by the computer that tells the car how cold to make the air coming out of the vents. We went for a drive. At around five minutes, that value slowly begins to rise until the target temperature set by the computer is almost 20 degrees higher. That explained why the air temperature consistently rises from 40 to 60 degrees under the conditions I already mentioned. The only way to reset the value and get the air cold again is to turn the A/C off then back on. It cools back down for five minutes and starts to go back up again.
Interestingly enough the tech said he never encountered this problem before and kicked it up the ladder to the Subie engineers. Turns out it wasn't a faulty control head or sensor, but it was doing exactly what they designed it to do. To kick the compressor off as much as possible to improve fuel economy.
Problem is, if I want to get better fuel economy by not running the air, I'll turn it off. If I'm hot, I want the air to be cold. We drove an identical Legacy on the lot and it performed exactly the same. If you spend the extra money and upgrade to a limited model with auto climate control, it blows 40 degree air non-stop. Evidently it operates differently than the manual controls because it has in cabin temperature sensor that regulates when the compressor shuts of or enters by-pass mode.
Oddly enough, when it gets really hot (90 plus degrees) the system seems to work well. If you want cold air March-May you are out of luck.
If you want to spend 20+ thousand dollars on a new car and expect the A/C to keep you cold, I suggest you keep driving past the Subaru dealership.
- Will B., Yukon, OK, US