W221 Serpentine belt diagram
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Joined: Oct 2010
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Couple things.
1) We have to remember that there are like 3 belt configurations for these cars, and that's just for V8s. M273 07-09 which has a conventional power steering pump. On the facelift 2010 and 2011 cars (US market, still M273), the steering is self-contained electrohydraulic with no external P/S pump. And then there are the M278 cars from 2012-2013 which I assume continue to use that self-contained electrohydraulic steering system.
2) The location in that diagram is used on the X166 for the hydraulic antiroll system (active curve control I believe it was called). There may well be another application where there is a pump there that is used for power steering but not on the W221.
1) We have to remember that there are like 3 belt configurations for these cars, and that's just for V8s. M273 07-09 which has a conventional power steering pump. On the facelift 2010 and 2011 cars (US market, still M273), the steering is self-contained electrohydraulic with no external P/S pump. And then there are the M278 cars from 2012-2013 which I assume continue to use that self-contained electrohydraulic steering system.
2) The location in that diagram is used on the X166 for the hydraulic antiroll system (active curve control I believe it was called). There may well be another application where there is a pump there that is used for power steering but not on the W221.
Also, my 2010 E550 has conventional power steering pump. I just replaced it a couple weeks ago but this 2012 S550 does not have a pump driven by the serpentine belt.
Is it then electronically driven pump that I have? There certainly is a reservoir for the fluid so there must be some sort of a pump I would think...?
MBWorld Fanatic!
Joined: Jun 2020
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04 E55 AMG (totaled), 07 S550 4Matic, 14 E63S
As I said, 2010-2013 W221 uses a self contained electrohydraulic power steering system. The pump is electric.
My 2014 E63 uses full electric power steering. I don't know when the W212 switched or if it was in that big 2014 facelift.
My 2014 E63 uses full electric power steering. I don't know when the W212 switched or if it was in that big 2014 facelift.
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,141
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
MBWorld Fanatic!
Joined: Jun 2020
Posts: 2,138
Likes: 870
04 E55 AMG (totaled), 07 S550 4Matic, 14 E63S
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,141
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
The pdfs have info mixed between cars with 273 and 278 engines though but that is fine...
