pnoyworx

So I have seen the other post such as this matter I am about to describe. I have searched and used the search function of this site.

After a couple of long drives from Seattle to Cali back to back I experienced a problem on both drives. After about 8hr drive or so the air would decrease to almost non existent to the cabin. But you can hear the fan working, and does change speeds when you press recirculate, etc. After shutting the car off for a few minutes the air would once again fill the cabin then slowly the air in the cabin would die down.

So this last trip, I brought it to a shop and we replaced the fan resistors and fan. Took the trip back home to Seattle, and it happened again. So I did some research, and could only find bits an pieces of information.

1. Some claim that it could be just low on freon....

2. Evaporator is freezing up, and an humidity sensor needs to be installed. possible Bulletin on this, but dealership can't find one.

3. Dealership states it's possible that it's the solar/sunload sensor on the hood not properly reading, causing flaps not to close.. etc.

Did anyone ever get a solid answer to a solution to this?

Also the diagnosis menu on the climate control unit, does anyone have a value data?
Most that I can find applies to an older model control unit. Another is, does anyone know how to switch the climate control unit to fahrenheit? Thanks in advance

Shifter

Your evap is def freezing. It could be simple as low on freon as you stated. That would be step one before going deeper.
How long has it been doing it for?

On a side note I have had too install resistors in the evap temp sensor line to adjust temp reading on other models before but that is a extreme case and think its prob something more simple.

Ronan Mc Cabe

I experienced the same issue, dealer came back with NTF (no trouble found) and not low on freon, their next suggestion was to replace the control module (I think the dash display) at a $1500 cost, they did not even know if this would fix the issue

pnoyworx

Has anything worked?

I think this is a hard one to diagnose since it happens many hours after operation. This I just recently found out since the past two months was the longest I took the car for a drive. Other than that it's been 4-5hrs max, my last few drives have all been in the 12-24hr drives, and have all occurred during these longer trips.

I really stuck here, since my Dealership denies any information on this matter, the only thing they come close to is the Sunload sensor, which I am willing to replace if I can get more info on how and what connection it has to the problem. I have also ordered a new ambient temp sensor, just to be certain that sensor is isolated since it's a pretty cheap sensor.

Ronan Mc Cabe

I have not been able to fix the issue but then again I have gone on 2 long (5+ hours) drives in 2 years.

LMK how you get on, I agree it's really hard to diagnose, when I stopped for a bite to eat (30 mins) during on of my trips all seemed to work fine after

pnoyworx

I will do, since most of the other info I find does not give us a completed result.

Mine does the same thing, it will work fine after having the car off for 30+mins. This would seem to explain something freezing, or overheating and then thawing or cooling off.... This is why I want to find out about the sunload sensor and see what play it has, since my dealer is suggesting it's that.

I am not saying my dealer is wrong, I have to give them credit for taking the time to research and make conversation, also the fact that they do not have the car in hand. But since I know they will not be able to duplicate this matter, I figured I would give them a call and see if they have come across anything like this, or have been briefed about this issue before.

SterlingE55

Mine does it too after ~3hrs. I run the fan with the AC off till it blows hard again. Kick the AC back on and all is normal for another 3hrs. I usually take the truck on long trips so its not really worth the cost to fix it as I believe it to be the control module as well.

Denroll

I had this same issue really bad last summer. I was down near the gulf in that thick humidity and it seemed like it was condensing and freezing. If I turned off the a/c for about 20 minutes, it would get better, before gradually freezing up. I fixed my problem by going back to San Diego

Yacht Master

Freezing up, if the dealer had no idea, you are going to the wrong dealer.
sun sensor, is 100% BS

novae500

possibly blower motor isnt working any more along with the compressor motor?

SterlingE55

The ole whales vag. Mine first shows symptoms on the way home from Salt Lake City to Denver which humidity should not have been an issue then. Still could have been freezing. I'm known to keep my AC low.

Critter

Not a AC expert by any means but freezing up is usually caused by a low Freon level, just saying. Had a recent issue with home AC and the tech just gave it a small shot of Freon and now it works flawlessly, he is the one who stated this fact to me. The lines were covered in ice at the unit.
If in doubt always blame the other guy,

pnoyworx

I replaced the blower motor along with the regulator, just to eliminate possible overheat and blower drawing more voltage than normal. My regulator "showed" some burning spots according to the mechanic that I had my car looked at in California. So I had them replaced even though I knew they were still working at the time. I figured the the fan could be over drawing power and in long drives causing the regulator to overheat, so in desperation to fix the problem during my drive I had it replaced. 900$ bill was added to my trip.

pnoyworx

So I want to try to eliminate the low freon situation. Does anyone know how much is supposed to be in there? I usually keep my climate on Auto 68, and my AC seems to blow cold enough for me. I'll find out on my next trip after July 4th if the l on freon is the culprit.

NorthernVA

I know this is an old thread, but this exact situation happened to me today. After 4 hours hardly any air was blowing out of the AC, but it sounded normal. Any new info on this issue? After the car sat for an hour, back to normal.

Denroll

Pick up one of those DIY a/c recharge kits with a gauge on it and a can of R134a without oils or dye. It will connect right on to the low pressure port and you can see if it is low. Probably is. I gave mine a charge and it helped a lot.

The port is in the back right part of the engine bay (driver's side) close to where the ECU is.

Critter

Yes I would say low Freon charge, as Denroll has stated.

NorthernVA

Is there a way to check the psi from the AC "hidden menu" i've been reading about? Thanks for the advice about the charge?

Critter

Do a search for "AC diagnostic menu" for your model car, #7 should be the charge value , but go through and list all values according to number.
There are members here to assist, just short on memory as to how to access the menu on your model.

Hulk

Only cars that have the "rest" button can access the secret menu

Critter

Figured it out this morning....

For the 05-06 model's we hold the driver side AUTO BUTTON feature for 10 second's.

Once Climate Control Data menu pops up, use the driver side TEMP UP & TEMP DOWN for toggle.


Sorry for the cut and paste but it was an easy search 06 E55 AC menu

Hulk

Did that holding of auto button, doesn't work

Critter

Key on position 1 or enough to show temp reading on AC console or try with the car running.

Critter

http://www.youtube.com/watch?v=7Ir23R6BmWA

Yacht Master

Its just frozen up, evap covered with ice. Once it thaws it's back to normal, this happens at low fan speeds and or closed outlet vents.