Rod Spohn

[QUOTE=zambezi2;6224770]The Duo valve is located on the drivers side under the plastic cover. easy to see and get at once the cover is off.

Tschuss_Bill

Correction:

Code 228 does not related to the Electric Heater. I just compared both valves. A2118320584 was the part installed in my CDI. A2118320684 looks almost the same but it has an extra hose fitting, see I marked it with blue tape in the picture. Having now done a bit more research on option code 228 "Auxiliary Heater", this is a fuel fed heater that resides in the fender well. I cannot imagine that US bound cars had this option available.

S430LUCKDRAGON

Awsome tutorial one question would it be located same place on other models ?

craigc

Thanks for the great DIY,
Did the test on pins 9 and 12 on the M4 connector of the drivers side SAM, its supposed to be around 10 ohms. Mine was 96 ohms.
Based on that I thought the driver chip on the drivers side SAM was blown so I ordered 2 because they are about $3.00 each. Turns out I didn't need them so If anyone needs them to repair their drivers side SAM I can sell them to you for cost or repair your SAM for cheap. (I've been a Electronics Technician for 25 years)
The code was 9027
I did remove the wipers, made it easy, about 45 min.
Like others I decided to open up the old valve.
The picture of the scan tool was taken after I replaced the valve so you can see the code from me disconnecting the wiper motor.
Erased the codes and rescanned the car and now have 0 faults.

moehler

Which connector is the M4 connector on the drivers side SAM, can you please post a pic?

craigc

The M4 connector is one of many connectors plugged into the underneath of the Driver side SAM so you have to remove the SAM to see it or get to it. Once you have the SAM removed you'll see the M4 connector. Sorry I didnt take pictures of the connector and I tried to find one for you and found the picture attached. I cant remember for sure but I think M4 is the very bottom right connector. I've also attached the MB bulletin that talks about testing the M4 connector.

Hope that helps

Jeffhixson4

Great instructions and illustrations! However, my only problem was after installing the new valve and putting everything back together, my windshield wipers won't work. 👎

craigc

I dont want to sound like a smart @%s but did you remember to reconnect the wiper motor ? Believe me its something I would do. If you did you may have to clear the code, please refer to my previous post of the description of the scan tool after I replaced the valve. I show the code for the wiper motor and the valve after I changed the valve.

Hope that helps

Jeffhixson4

Thank you,!!! I'll check 👍👍

craigc

Your very welcome, I love these cars. The post I was refering too is post #229.
My scan tool showed code (9050 wiper motor) and (9027 heater exchange shut off motor) after I replaced the valve. This surprised me because the car was turned off during the whole valve replacement. I cleared both codes and all was well.

IMIEIW

Thank you, at least I know what direction to go. Went out this AM and had a passenger in the rear. He wanted to know why it was so hot back there. I guess this is one answer. As stated in some of the earlier posts, this seems to be an intermittent problem. Without a scanner, which I have to get, which one I don't know, it is hard to diagnose properly. What fuses are associated if any?

demoned

Hello to all!

Thank you for the excellent explanation.
I have an issue after placing the new one, it leaks and I am not able to stop the leakage on the lower entrance pipe that goes inside the car. Do i need to use special seal component in order to stop this leakage or am I doing anything wrong.

moehler

I replaced the heater valve (twice) and it didn't solve my intermittently hot air from the rear vents issue... thanks to craigc, I replaced the heater valve control chip in the SAM, and it fixed the issue completely. Here's a link to my thread -

https://mbworld.org/forums/w211-amg/...trolvalve.html

demoned

Finally fixed the issue through and painful process in replacing the radiator that the valve is connected. The corrosion had damaged the radiator pipes giving no chance in sealing the leakage.

Cliviscus

I have a RHD E320 W211 and have changed the heater control valve situated under the Brake Master Cylinder and alas much to my disappointment there is no change and I still have cold air blowing out the vents. Any ideas would be greatly appreciated.

demoned

The heater control valve, it is not where are you describing it. Are you sure you changed the right valve??

craigc

I'm guessing he did replace the correct valve, its in a different spot than our left hand drive cars. see here

craigc

Did you open up the original changeover valve to see if there was evidence of leaking and or corroded/broken pieces inside?

Cliviscus

I believe it to be the right valve and after wiping away the many tears I actually took the car for a run and think there may have been an air lock as after a short while it started blowing hot air God bless it. Many thanks

Mr. CVE

Yes the RHD cars ( like mine ) the heater tap is in a spot that is almost impossible to get to !
I did mine as well, nearly killed me !
I read this post, though... easy job and bought the parts, pulled it apart and was like... how am I going to get to that !!
All good now.

Heatwave

Is this a heater changeover control valve problem: Occasionally my '07 E350 will quit producing a/c cool air through the control vents in the dash and in the console. It sounds like the ducts inside the dash are closed ... I can hear the a/c blower motor operating, but nothing comes out of the vents. I discovered that I can stop the car, turn off the engine, restart it, and the a/c control doors return to normal operation. Control valve?

sealrockswell

Thank you so much W211 Ryda. This tutorial was perfect and resolved the unbearable heat issue. I too live in SoCal and this was really killing me this summer. WHat part of SoCal are you from?

abu bakar

nice job brother DIY

Cliviscus

Interesting to note that when I took it to my normal service agent he suggested I left it with him for a day to diagnose. Returned to pick it up said he was waiting on an email before quoting me. I said so you need a photo of the part so then you can locate it and we both shared a laugh. After some great advice from this forum and not disclosing it to this guy returned to get my quote which was $400.00 AUD for the part and 8 hours labour. I phoned the local dealer who quoted me $158.00 AUD, I then phoned a supplier in Melbourne who imports his own parts $126.00 AUD with overnight delivery included and it took me approximately 3 hours plus a reasonable amount of skin and blood loss.
Many thanks guys for your valuable advice

IMIEIW

Thanks so much for the pictures and advise. I was lucky and only broke 1 clip. Job went well and now we're hanging meat.