W204 in limp mode.

Hampstead

New Member
Joined
May 23, 2020
Messages
13
Location
Essex
Car
C350 CDI W204 2010
I took my car for diagnosis and the error code pointed to the EGR valve.

They fitted a new one and it went into limp mode on the way home. They have tried various things including new hoses and replacing the engine exhaust temperature sensor.

So, today I bought an ODB reader and the code was P0401 Exhaust EGR Flow Insufficient.

It’s a W204 350 CDI 2010.

Any ideas what they have missed!
 

markjay

MB Master
SUPPORTER
Joined
Jun 24, 2008
Messages
26,018
Location
London
Car
W204 C180 Executive SE 2013 Automatic / COMAND NTG4.7 and Morel speakers fitted by www.comand.co.uk
The generic OBDII reader won't give you much info.

If you intend to tackle this DIY, then at the very least you'll need something like the iCarsoft MB v2.

Better still, take it to a specialist who will have proper STAR diagnostic computer, and more-importantly understands how to view live data and how to carry out the diagnostic process.
 
OP
OP
H

Hampstead

New Member
Joined
May 23, 2020
Messages
13
Location
Essex
Car
C350 CDI W204 2010
I’m taking the car back to them after the weekend. I was hoping there would be a simple thing that commonly gets missed.
 

HITECH

Active Member
Joined
Dec 25, 2014
Messages
496
Location
coldest place in scotland
Car
C220 CDI
This sounds like a typical boost/MAF/DPFE problem which is very common to kick up a FALSE P0401 including on any STAR diagnostic hence the reason why they have replaced the EGR when its clearly nothing to do with the EGR valve.
 
OP
OP
H

Hampstead

New Member
Joined
May 23, 2020
Messages
13
Location
Essex
Car
C350 CDI W204 2010
This sounds like a typical boost/MAF/DPFE problem which is very common to kick up a FALSE P0401 including on any STAR diagnostic hence the reason why they have replaced the EGR when its clearly nothing to do with the EGR valve.
J
 
OP
OP
H

Hampstead

New Member
Joined
May 23, 2020
Messages
13
Location
Essex
Car
C350 CDI W204 2010
This sounds like a typical boost/MAF/DPFE problem which is very common to kick up a FALSE P0401 including on any STAR diagnostic hence the reason why they have replaced the EGR when its clearly nothing to do with the EGR valve.
So, what’s the next step? The garage have given up.
 

OneForTheRoad

MB Enthusiast
Joined
Apr 20, 2015
Messages
2,439
Location
uk.
Car
2015 w204 c class amg sport premium +65 ford kuga 2.0 cdi zetec awd..
Have a look for any carbon blockages .pre and post egr. Also did the new egr come with exhaust back pressure sensor or did they use the old one ?
 

HITECH

Active Member
Joined
Dec 25, 2014
Messages
496
Location
coldest place in scotland
Car
C220 CDI
Can u stick a picture of your engine in here for me to see please. Carbon blockages etc and sticking EGR valve and pipes n stuff are all never the source of this problem and this is why it is so frustrating for customer and the garages. The garages follow protocol. Change part according to fault code. Unfgortunately 9/10 the P0401 is never the EGR valve. A picture of ur engine please if possible or stick ur VIN here and i can get a proper look at it and others can maybe help more with the VIN being able to access what it has and does not have.
 
OP
OP
H

Hampstead

New Member
Joined
May 23, 2020
Messages
13
Location
Essex
Car
C350 CDI W204 2010
Model: C Class (2007-11)

Range: C350 4Dr Saloon 3.0 CDI BlueEfficiency DPF 231 EU5 Sport Auto7

VIN: WDD2040252A377413
 

zipdip

MB Enthusiast
SUPPORTER
Joined
Mar 5, 2015
Messages
2,873
Location
Essex
Car
s320
Well there are some good indy's in Essex I use one in Colchester,there is a couple in the Romford and Basildon areas,you need it on a star.
 

HITECH

Active Member
Joined
Dec 25, 2014
Messages
496
Location
coldest place in scotland
Car
C220 CDI
Was looking at ur engines basics. From memory I have had a faulty MAF sensor kick up an EGR P0401 fault before on one of them. I would attempt to do this. UNPLUG THE MAF sensor. Tuck the connector away somewhere safe and close your bonnet. Then clear the codes. then drive it and see if it still goes into limp mode. This needs to be done.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top Bottom