rtbrjason

Did some searching prior to posting but most threads are geared toward older model w211's. None of the reset procedures I've read about appear to relate to this setup.

When I push the AC button, it blinks red 5 times and then goes out. No cold air at all.

I had my normal mechanic friend hook it up to his shops AC machine and found that it was fully charged.

Any ideas before I have to take it to the dealer?

kajtek1

I can count about 15 things that affect AC on those cars, so dropping parts blindfolded can turn costly.
Have the car scanned, or buy 4-zone climatronic where you will be able to scan yourself using its LCD display.

rtbrjason

What do you mean by "buy 4-zone climatronic"? I did a quick google search but not seeing anything pertinent.

kajtek1

I have the whole option from factory, but members report that they change the climatronic unit only and it is plug&play.
When they did it for cool factor, it allows reading car sensors with no need for additional scanner
Options that DIY like me, not having SD just love.
My climatronic is having different buttons, so it operates slightly different, but you'll get the idea.
Since you are in need for a scanner - you might like the idea as well.

rtbrjason

I do have a same or similar climate control to that in the video. I do not have the rest button, but find I can access the menu with the 1-99 data points by holding left side auto for 5 seconds. Not sure what if anything in this menu will perform a ac system reset and/or clear fault codes.

When looking up how to reset, I find that I need to hold defrost and recirc, but those two buttons share a rocker switch and cannot be depressed simultaneously.

Is there a method for either reading or reseting the system from the "secret" menu on the AC display?

kajtek1

Post a picture what would help. Seems the climatronic come in several configurations.
Did you find errors?
Anyway, if you can access sensor readings, read 0 or 1-8 in 3 situations.
1. in the morning before engine start.
2. in the afternoon when entering hot car before engine start
3 couple minutes after #2 with engine running when AC should work at full blast.
Usually from those 3 readings I can troubleshoot the system with 98% accuracy.

konigstiger

Definitive diagnose need to pull fault codes using MB SDS. One thing you can try since independent claims fully charged is to attempt a reset by disconnecting module, wait at least 5 minutes before reconnecting.

rtbrjason

Thanks. I'm working on getting the data kajtek1 asked for and will give this a try as well.

rtbrjason

Here is the photo of my AC control unit as well as a photo of the data points you requested (00-08). I'm not sure how to, or if there is anyway to read the hvac fault codes from this control unit.

rtbrjason

After looking this over, I'm guessing the data point "8" is the problem. Looks like that would be the refrigerant temp sensor either having gone bad or being unplugged. A parts search reveals some difference from the E500 to the E550. As of now, the only part I see for the E550, seems to be "A/C evap temperature sensor" (part # 2208300772). Not sure this is the correct part or not though.

kajtek1

rt is right about refrigerant sensor dead, so check the plug. I know older system has default mode for such occasion, so I hope your car does as well.
But main issue is low refrigerant.
4 bars is nothing to cool it. You need to have over 20 bars at full output.
I would add a can of R134 and recheck again. Most likely will take 2nd, but better be slow than sorry.

kajtek1

Also your engine sensor shows 16C with 30 outside, but I would not touch it before additional readout.
On 2nd tough, so many bad sensors is hard to believe.
Check all plugs and wiring for damage.

Plutoe

You have been led on a misinformation trip--the poster is known as the biggest spammer--he knows nothing about the MB AC system and offers kindergarden suggestions such as spending thousands on a 4 zone control unit that will not work on you model---all to grab posts!!


To answer your question---no you can't reset and diagnostics with your control unit---see yesterdays post on the DAS Xentry aka Star Diagnosis System that is used to diagnose the MB AC system.

Get serious and get the correct technical help!!

rtbrjason

Mercedes parts counter verified the pressure sensor is also the temp sensor for the AC. As the refrigerant temp is showing 99c, I decided to order a new sensor. I had my mechanic friend remove all the 134, changed the sensor and put a full charge in it (2.1lbs).

Since the AC won't come on, in order to get it to take a full charge, we had to provide power to the ac compressor using the blue with a green wire in the drive side underhood fuse box. AC works when providing power to that line as the compressor kicked right on, got a full charge and the AC line was ice cold.

When I turn the AC on in the car, I still get the 5 blinks and then it goes out. Refrigerant temp still reads as 99c as well.

Clearly something electrical is going on and not powering that blue/green wire when the AC switch is pressed. I guess I'm taking it to the dealer.

kajtek1

Taking spammer advice and spend big money is always an option, but automotive forums were crated to avoid such situations, so try 1 more thing.
W211 still have lot of hidden features and people like Plutoe don't want you to know that.
I can't guarantee success, but per my observations - even W211 having different buttons on climatronic, still have the same features.
So here is your chance to make it to forum history and prove Plutoe idiot.
Go to W210 site and try to follow the code reading logic with your buttons.
All you have to loose is few minutes. I would even try it on our W211 but wife just left in it and my climatronic is different from yours.
Good luck
http://www.mercedesmedic.com/ac-air-...le-codes-list/

rtbrjason

Thanks. I have seen this page while scouring the net for how to read diagnostics on my AC panel. Obviously I don't have the pictured AC unit. I would give it a try anyway, but I don't have the "REST" button so not sure what to substitute with. I will try some button combinations of defrost with another button while the reading is on low and see if anything gets me into the diagnostic mode.

kajtek1

On my W211 climatronic "rest" and "AC" is same button. Hope that helps.
I should have some time tomorrow morning, so will try that on my end.
It is like reading criminal book and seeking the clues.
Or my wife spends long hours doing cross-puzzles.
The main difference is that we can actually "make" money doing this

rtbrjason

This page (post 1) seems to be the closest thing I've found. I will try defrost and AC with the drive side set to Hi and the passenger to Low.

http://www.benzworld.org/forums/w210...uble-code.html

kajtek1

I spend few minutes on our W211 and could not find way to access errors.
Net search did not find anybody posting errors readout on W211, but here is a guy speaking Arabic who does that on W220.
Can't understand what he is saying, but evidently he is reading and erasing AC codes, what makes me thinking that unless there is a good reason MBUSA disabled the option, we should get there sooner or later.
On edit, I emailed MBUSA with question, but it is weekend, so might take few days to get response.

rtbrjason

Gave this a try today. Didn't make any difference. Made an appointment with dealer for next week. Diagnostics start at $115.

kajtek1

You've got it cheap brother. My local stealers start at $150.
Got the reply from MBUSA about hidden menu and they are firm that such information can be given only by dealer.
Maybe for $115 you can get that info as well?

Plutoe

OOOOOOOOOOOOOOOOOps

kajtek1

It is about time somebody take care about this idiot above.
Moderators promise to take care of him for months, but nothing has changed.

rtbrjason

You've obviously got a problem with Kajtek1. I don't. He at least tried to provide some suggestion while you've only bashed him and provided no help in this thread. If you have anything constructive to say regarding the issue, please feel free, otherwise there's no need for you to reply.

Plutoe

You are correct!!