S550 rear climate control only blows hot!
Thread Starter
Newbie
Joined: Jan 2013
Posts: 5
Likes: 0
S550 4matic, E320 4matic
S550 rear climate control only blows hot!
I have a 2007 S550 4matic with rear dual zone climate control. A few months ago I noticed the rear vents were only blowing very hot air despite setting the controls to any temperature, even the coldest setting. This issue remained whether on auto or manual control. When I shut the rear climate control off then the center console becomes extremely hot. I reviewed several posts that described similar issues and all recommended replacing the "heater control valve (solenoid valve)". This is the part that is located on the firewall just under the wipers on the driver side in the engine compartment. I ordered the part from Pelican Parts and replaced it with some difficulty as the C clamps are difficult to reach in this tight space. After about 2 hours of "fun" I finally completed the replacement only to find the problem with the rear heater was still there, no improvement. I would appreciate any thoughts or suggestions regarding this issue and I would seriously like to avoid taking the car into the dealership for a diagnostic.
Also of note: the right side blows very hot, the left side blows warm. Front climate control works perfectly but when rear is turned OFF then hot air bleeds through center console and cup holder area.
Also of note: the right side blows very hot, the left side blows warm. Front climate control works perfectly but when rear is turned OFF then hot air bleeds through center console and cup holder area.
Newbie
Joined: Jun 2011
Posts: 6
Likes: 0
From: Toronto
2007 S550 4matic
Hi all, I have 2007 S550 with the exact same issue. I replaced the heat exchange control valve located under windshield wipers and same issue still. Any idea of what could it be? I scanned the A/C and I got two codes, 920A ( A31/1m1 circulation pump overload) and 9375 (A31/1y2 RIGHT DUO VALVE SHORT CIRCUIT TO POSITIVE OR OPEN CIRCUIT)
Member
Joined: Dec 2010
Posts: 96
Likes: 0
From: NYC
'01 S500 AMG Sport, ABC,Distronic,Rear Side Shades // '10 E350 P2, Pano, BLK/ALM,4MATIC Sport
S550 rear climate control only blows hot!
Originally Posted by WilliamMB
Hi all, I have 2007 S550 with the exact same issue. I replaced the heat exchange control valve located under windshield wipers and same issue still. Any idea of what could it be? I scanned the A/C and I got two codes, 920A ( A31/1m1 circulation pump overload) and 9375 (A31/1y2 RIGHT DUO VALVE SHORT CIRCUIT TO POSITIVE OR OPEN CIRCUIT)
Newbie
Joined: Feb 2015
Posts: 1
Likes: 0
Correct, had same problem on 2008 S550, let it go to long, cracks developed in the wood/plastic from the heated console. Under the front right fender is where the valve is located. Fixed my problem
Super Member
Joined: Dec 2005
Posts: 806
Likes: 27
From: Rochester, NY
2009 S550 AMG sport pckg. 2014 Ford F-150 Lariat Supercrewcab
Yup sounds like it's the duo valve/heater control valve. It sits in the front passenger side fender. It's not cheap it's about 400 for the part. I'll get a part number on it for you if you want
Trending Topics
Super Member
Joined: Feb 2012
Posts: 681
Likes: 81
From: ToRonTo, OnTaRiO, Khanaadah
s550
hey
Please do. Mine has been like that for a year. Luckily no one is ever in my backseat.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
Former Vendor of MBWorld
Joined: Jun 2015
Posts: 423
Likes: 0
1985 500SEC
hey guys, i would need to know the factory part # to be 100% sure but these are the valves that i offer, i hope this helps. if someone can provide the factory Mercedes number i can cross reference to be positive.
https://www.carpartsdiscount.com/cat...html?3594=2215
Please let me know if i can be of any further assistance
https://www.carpartsdiscount.com/cat...html?3594=2215
Please let me know if i can be of any further assistance
Junior Member
Joined: Feb 2016
Posts: 32
Likes: 3
08 S550 4Matic w/ AMG Pkg & P3
Just fixed mine...see my post here, hope it helps you guys fix your issue.
https://mbworld.org/forums/s-class-w...-hot-cold.html
https://mbworld.org/forums/s-class-w...-hot-cold.html
