Hello, I was just wondering if someone might be able to help me out here. My a/c compressor will not engage normally. I just had a new compressor put in and it recharged. The evap temp sensor and everything was checked out and is all showing good. I put a new pressure transducer on it and at first it was showing good pressure on the acp sensor and was working fine. The pressures on the gauges are still showing good but the pressure switch is showing lower between 0 and 50 psi . I put another one on it thinking maybe i got a bad one and now its doing the same thing. It's showing too low to allow anything to come on I think.

Oddly, I can unplug the battery for a few minutes and then start the car and turn on the a/c and it will kick right on and start working. After I shut the car off though it all goes back to doing the same.

Thank you i've been havin ga lot of trouble with the a/c on this thing

 

Im having the same issue currently. 2011 Ford fusion sel. Freon levels are good. Just replaced the Evap temp sensor to no avail. Did you ever get this issue figured out?

 

Hello Paul, no I haven't figured it out yet. I ordered a new PCM it is suppose to be here monday or tuesday so I'll see how that goes. If that doesnt do it I will try changing the wiring plug that goes into the pressure transducer but after that I'm kind of at a loss. One thing I havent tested yet was to see if the alternator is charging right. I'm not sure if that would cause the sensor to show wrong but I have read that they can cause a/c issues so I'm not sure. I will try not to forget and let you know how the PCM change goes.

 

REMINDER, JUST IN CASE YOU FORGOT !!

If you plan on changing the PCM, please be aware you will need to do a parameter reset with a capable scan tool.
If this step is overlooked ,the PCM will not recognize the vehicle with the anti-theft system and you could have a problem trying to get the vehicle started.
IN ADDITION to that, if you reinstall the original PCM the vehicle is now confused and will not start even with a former working PCM.

 

Hello, I was just wondering what you mean by the parameter reset? The one I ordered is suppose to be pre programmed with the vin number I gave them and updated. Is that what it needs? I know I might have to reprogram the keys as well.

 

@ Paul Kinsman,

I just thought I would update you. I got the new pcm and after a little trouble getting the keys reprogrammed it still did not fix the a/c issue. The only thing next I know to try is I am going to try and change out the wiring to the pressure sensor.

 

I also have a 2010 Fusion with the A/C not working I replaced the evaporator sensor, pressure sensor and even had it reprogrammed from the ford dealership and it still wont work. The dealership said I had a wiring issue from the fuse relay to the compressor. I check that this weekend, but of course with the relay in I have no voltage going to the compressor. If I jump the the post after pulling the relay I am getting voltage to the compressor and it works. I can jump it and plug the relay back in and it will work fine until you shut the car off. You can shut the A/C off inside the car and turn it back on and it works. But if you shut the car off it won't.





I had a very reliable mechanic shop tell me that I need to replace the PCM, because something is shorted out with it. I have voltage to the fuse panel when I turn on the A/C inside the car, but something is not going thru the relay.





Does any have a suggestion?

 

have you tried to jump your fuse pole using a pc of wire? JSut to see if you can get the compressor to engage?

 

Hello Bdilbeck. I can get the compressor to come on with the scan tool and as long as my pressure sensor is reading about 70 psi or above I can turn the a/c on with the buttons. But the pressure sensor never shows what the gauges show and after I turn the a/c off it quickly goes back down to like 12 psi even though the gauges are showing good. I can also unplug the battery for a minute and the a/c will turn on for a few minutes until i take it for a drive or shut the car off.

I just changed the PCM in mine and it's still showing the same as the old one. I'm kinda clueless at this point.

 

I am like you.. I am at a loss for sure. I really don't want to spend any more money on it either. But I might send my PCM off to have it rebuilt cheaper than a refurbished one. But I am not sure that will solve it. I guess I could always run a switch to the interior of the car and turn it on and off.