Air con issues E55 W211

[Myfirstamg]

Hi guys, I recently bought a 2004 E55 AMG but have only just noticed that the air con/climate control isnt working as it should. It seems to display ok and blow ok and also hearts up ok, but it doesn't blow cold. Assuming it needed a re-gas so took it to quick fit to have thew system re-gassed and they said there is plenty of pressure in there its just not working.
So being a total merc newb im asking for some advice. Are there any common issues with these? Where and how do i check the system? I dont even know the fuse location to check!!
Very newb questions i know but as this is my first merc i dont have a clue really. I did run a diognostic scan last night using a snap-on solus plus scanner but nothing found

 

[AMGeed]

More than likely you need to change the duo valve. Its in a really awkward position against the bulkhead on the drivers side. Unless you are really handy at DIY, don't attempt it yourself.
The valve isn't very expensive, but labour may be a little more.
Here is the state of mine opened up after I noticed hot air blowing out of the rear vents when it was on cold.

 

[Myfirstamg]

Ooo i dont mind a bit of diy, i have a full workshop and am mechanicaaly minded so its not an issue. I'll look at it tomorrow but i think that isnt the issue as the air con doesnt seem to be clicking in at all, No noticable engine noise change ect when you turn the temp on to low. I found both fuse boxes tonight but all fuses were good, couldnt see a specific fuse/relay for the air con!!?? so very confused

 

[Nellie Spence]

Not up on the E55 but you probably have 3 fuse boxes. One under bonnet, one in the boot and one at end of the dash against the door panel. Hopefully a fellow owner may confirm.

 

[Myfirstamg]

Yeah i found the one at the dash side, the one in the boot also but didnt find one under the bonnet.
Just seen a video of how and where the duo valve is located on youtube. Looks a right pig of a job especially because i have big hands. I guess there is no way of telling if its knackered or not by looking the only way is removal on which point i may as well change it anyways

 

[AMGeed]

Just seen a video of how and where the duo valve is located on youtube. Looks a right pig of a job especially because i have big hands. I guess there is no way of telling if its knackered or not by looking the only way is removal on which point i may as well change it anyways

That's about the sum of it. My indy removed the throttle pedal , pulled the SBC pump to one side to give him some room and took about 30 mins in total to do the job.
As you say, no way of knowing if that is the problem for certain, but that is my guess. Have you a local indy you can get some advise from?

 

[Myfirstamg]

That's about the sum of it. My indy removed the throttle pedal , pulled the SBC pump to one side to give him some room and took about 30 mins in total to do the job.
As you say, no way of knowing if that is the problem for certain, but that is my guess. Have you a local indy you can get some advise from?

Indy??

 

[andy27168]

Hi,
Indy=Independent=Mercedes Benz specialist.
I think you need to have the car put on STAR so the values of the various sensors can be read, it also maybe that the previous owner had the system recharged at some point and if it was ever empty and even if recharged won't work till the codes are cleared and system reset. The Snap-on SOLUS might be a good code reader but I wouldn't leave it there till it has been plugged into STAR.
Where are you in the UK? So we can recommend an Independent near you.
If you are in driving distance from Southampton I can read/reset the codes if you wanted.

 

[Nellie Spence]

Yeah i found the one at the dash side, the one in the boot also but didnt find one under the bonnet.
Just seen a video of how and where the duo valve is located on youtube. Looks a right pig of a job especially because i have big hands. I guess there is no way of telling if its knackered or not by looking the only way is removal on which point i may as well change it anyways

Top left corner as you open the bonnet, slide back the two tabs and lift.

 

[Myfirstamg]

Hi,
Indy=Independent=Mercedes Benz specialist.
I think you need to have the car put on STAR so the values of the various sensors can be read, it also maybe that the previous owner had the system recharged at some point and if it was ever empty and even if recharged won't work till the codes are cleared and system reset. The Snap-on SOLUS might be a good code reader but I wouldn't leave it there till it has been plugged into STAR.
Where are you in the UK? So we can recommend an Independent near you.
If you are in driving distance from Southampton I can read/reset the codes if you wanted.

Im just south of lincoln, And being a merc newb i have no clue if there are any "indy"s around here. The only thing i know of is the main dealer.
Is it worth changing the duo valve anyway? For £32 and a lot of swearing and shredded knuckles i may as well hadnt i?

 

[Myfirstamg]

Can anyone confirn the exact location of air-con fuse or/and relay for the w211 e55? So i can at least rule them out

 

[Myfirstamg]

So Managed to get a proper diognotic on it today and came up with the fault code

9450 Air conditioner multifunction sensor faulty

So ive done a little internet search and figured that out to be the "Gaseous pollutant sensor" thats under the bonnet under the driver side window screen. Does that sound about right??

 

[andy27168]

Hi
To be honest I knew there was a sensor of some sort under the bonnet but never realised its full function, and didn't think it's failure wouldn't allow the A/C not operate, I did a little googling and looked at the EPC the replacement sensor pt. no. for your car is
A 211 830 04 72, It retails from MB for an eye watering £298.80
I found one on E-bay from a recommended (on the other UK MB Forum) MB Breaker in the link below,
MERCEDES W220 S CLASS AIR POLLUTION SENSOR 2118300472

I take it the fault code was current and you tried to clear it?

 

[Codger49]

When I first acquired my W209, it had a fault code stating 'unable to communicate with pollution sensor', because its connector had been unplugged. The a/c seemed to work quite normally though.