Jun 16, 2015, 01:44 PM
Last edit by: IB Advertising
See related guides and technical advice from our community experts:
Browse all: Steering and Suspension
- Mercedes-Benz C-Class: Why is My Suspension bouncy?
Guide to diagnose trouble and recommended solutions
Browse all: Steering and Suspension
Comfort and Sport mode
Junior Member
Joined: Aug 2020
Posts: 55
Likes: 2
From: Hyderabad, Telangana
EQC, S Class Extended, Grace CVT.
some markets get extra garbage for goodness knows what on various part of the emission systems
the w221 should have a DPF and they give all sort of fun when its going wrong / not regenerating correctly
Engine breather was a bad design and that plays up, there was a modified part with red seals (but shouldn't give silly issues)
Fuel filter needs regular changes, some have a sensor in them that costs much more - forget for what - water detection and or heater? (its sits above that useless swirl flap drive motor in the middle of the V
the w221 should have a DPF and they give all sort of fun when its going wrong / not regenerating correctly
Engine breather was a bad design and that plays up, there was a modified part with red seals (but shouldn't give silly issues)
Fuel filter needs regular changes, some have a sensor in them that costs much more - forget for what - water detection and or heater? (its sits above that useless swirl flap drive motor in the middle of the V
MBWorld Fanatic!
Joined: Aug 2014
Posts: 5,317
Likes: 1,673
S500
re the breather - the actual separator has a diaphragm in the cylindrical bit - it falls to bits inside and they modified it - looks much the same later part number and one bit has a hose clamp and red seals
Junior Member
Joined: Aug 2020
Posts: 55
Likes: 2
From: Hyderabad, Telangana
EQC, S Class Extended, Grace CVT.
Thanks again Sir Botus. I'm buying after market silicone made seals for the turbo and breather. The breather has a sensor.
MBWorld Fanatic!
Joined: Aug 2014
Posts: 5,317
Likes: 1,673
S500
loosen the air boxes take off the bat wing and look at the turbo impeller - is it in good condition and does it spin OK
and double check what on the E class w211 is F44 in the front SAM its a 15AMP fuse and is badly named on the that model it does "Inlet port shut off, Turbo actuator, EGR valve and the Exhaust back pressure sensor
might be on the W221 F24 25AMP CDI Control Unit N3/9 (10 amps more due to the DPF ?)
the weak name on the W211 is F44 15AMP Valid for engine 646, 647, 648: CDI control unit
I've lost track of the symptoms you have...
and double check what on the E class w211 is F44 in the front SAM its a 15AMP fuse and is badly named on the that model it does "Inlet port shut off, Turbo actuator, EGR valve and the Exhaust back pressure sensor
might be on the W221 F24 25AMP CDI Control Unit N3/9 (10 amps more due to the DPF ?)
the weak name on the W211 is F44 15AMP Valid for engine 646, 647, 648: CDI control unit
I've lost track of the symptoms you have...
Junior Member
Joined: Aug 2020
Posts: 55
Likes: 2
From: Hyderabad, Telangana
EQC, S Class Extended, Grace CVT.
loosen the air boxes take off the bat wing and look at the turbo impeller - is it in good condition and does it spin OK
and double check what on the E class w211 is F44 in the front SAM its a 15AMP fuse and is badly named on the that model it does "Inlet port shut off, Turbo actuator, EGR valve and the Exhaust back pressure sensor
might be on the W221 F24 25AMP CDI Control Unit N3/9 (10 amps more due to the DPF ?)
the weak name on the W211 is F44 15AMP Valid for engine 646, 647, 648: CDI control unit
I've lost track of the symptoms you have...
and double check what on the E class w211 is F44 in the front SAM its a 15AMP fuse and is badly named on the that model it does "Inlet port shut off, Turbo actuator, EGR valve and the Exhaust back pressure sensor
might be on the W221 F24 25AMP CDI Control Unit N3/9 (10 amps more due to the DPF ?)
the weak name on the W211 is F44 15AMP Valid for engine 646, 647, 648: CDI control unit
I've lost track of the symptoms you have...
Junior Member
Joined: Aug 2020
Posts: 55
Likes: 2
From: Hyderabad, Telangana
EQC, S Class Extended, Grace CVT.
@BOTUS God willing you were correct. It is the back pressure exhaust manifold bit, that comes in two parts, glow plug 5 and 6, and the sam front communication.
The actuators are either malfunctioning or completely burnt.
The actuators are either malfunctioning or completely burnt.
Last edited by Numair Aidroos; Mar 16, 2022 at 11:53 AM.
MBWorld Fanatic!
Joined: Aug 2014
Posts: 5,317
Likes: 1,673
S500
@BOTUS God willing you were correct. It is the back pressure exhaust manifold bit, that comes in two parts, glow plug 5 and 6, and the sam front communication.
The actuators are either malfunctioning or completely burnt.
The actuators are either malfunctioning or completely burnt.
back pressure sensor = what tells the VGT gas flow where to land on exhaust side of the turbo impeller to control what amount / when to boost - at 100k miles the diaphragm wears out and it reads silly numbers - the car will drive a bit gutless down the bottom and can remain EML off
the glow plugs impact start up and emissions as low temps - they have almost no impact on performance
the F SAM probably just lies - these things event error codes every 100 yards and of course the passenger side door mirror pops its heater every other mile - so that will always return a fault on 99% of cars built
13 years after build Merc noticed some coding in the rear SAM they never thought about - so the car's have always been showing an error for the hall sensor position on the re the rear window blind in the Rear SAM
Junior Member
Joined: Aug 2020
Posts: 55
Likes: 2
From: Hyderabad, Telangana
EQC, S Class Extended, Grace CVT.
back pressure sensor = what tells the VGT gas flow where to land on exhaust side of the turbo impeller to control what amount / when to boost - at 100k miles the diaphragm wears out and it reads silly numbers - the car will drive a bit gutless down the bottom and can remain EML off
the glow plugs impact start up and emissions as low temps - they have almost no impact on performance
the F SAM probably just lies - these things event error codes every 100 yards and of course the passenger side door mirror pops its heater every other mile - so that will always return a fault on 99% of cars built
13 years after build Merc noticed some coding in the rear SAM they never thought about - so the car's have always been showing an error for the hall sensor position on the re the rear window blind in the Rear SAM
the glow plugs impact start up and emissions as low temps - they have almost no impact on performance
the F SAM probably just lies - these things event error codes every 100 yards and of course the passenger side door mirror pops its heater every other mile - so that will always return a fault on 99% of cars built
13 years after build Merc noticed some coding in the rear SAM they never thought about - so the car's have always been showing an error for the hall sensor position on the re the rear window blind in the Rear SAM
Should I get the indie to get the back pressure actuators changed or the turbo vgt? Why is there a diaphragm for the actuators?
Thanks yet again God willing to have you here Botus.
MB World Stories
The Best of Mercedes & AMG
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
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Aug 2014
Posts: 5,317
Likes: 1,673
S500
the black VGT actuator is one of the first designed to fail features they introduced - the wires vibrate off the circuit board between that and the multiplug connector (just like TEVES and the rest did with the ABS modules) - pop the silly clips off and double check, clean the gunk on the screw and very lightly add some lube and if a link wire is adrift resolder it - or waste 140 dollars on a new one. But sometimes the VGT bit gums up and just wear out...
Junior Member
Joined: Aug 2020
Posts: 55
Likes: 2
From: Hyderabad, Telangana
EQC, S Class Extended, Grace CVT.
back pressure sensor - its a small sensor - one of easiest jobs on the car it sits back right of the engine near the turbo (in fact between the turbo and EGR) needs a 24mm deep socket and watch out for the washer - the dim dealers usually have the sensor but don't carry new washers !!!
the black VGT actuator is one of the first designed to fail features they introduced - the wires vibrate off the circuit board between that and the multiplug connector (just like TEVES and the rest did with the ABS modules) - pop the silly clips off and double check, clean the gunk on the screw and very lightly add some lube and if a link wire is adrift resolder it - or waste 140 dollars on a new one. But sometimes the VGT bit gums up and just wear out...
the black VGT actuator is one of the first designed to fail features they introduced - the wires vibrate off the circuit board between that and the multiplug connector (just like TEVES and the rest did with the ABS modules) - pop the silly clips off and double check, clean the gunk on the screw and very lightly add some lube and if a link wire is adrift resolder it - or waste 140 dollars on a new one. But sometimes the VGT bit gums up and just wear out...
