Do MAF's have to be coded.

G-a-r-y

Senior Member
Joined
Feb 7, 2006
Messages
557
Reaction score
4
Location
Bristol
Your Mercedes
S211 320 CDi, SLK 200 R171.
Daft question I know, does a MAF need coding. Euro have a good discount at the moment so I bought a new one for £151. E320cdi 2004.
 

_Taz_

Senior Member
Joined
Oct 24, 2010
Messages
482
Reaction score
5
Location
Kent
Your Mercedes
2011 E63 6.3NA AMG Tenorite Estate MCT 7g
nope straight swap....

however I am just wondering if the adaptations need resetting...

same as if you've changed an air filter ?

I remember doing this once I replaced my crapped out old air filters.
 

Carl@MBS

<span style="color: red;">Authorised Forum Support
Joined
Oct 8, 2012
Messages
139
Reaction score
1
Location
Southampton
Your Mercedes
164 320 AMG & 211 320CDI
2004 320cdi maf?? they are cheaper than that from mb for the 320cdi straight 6! its only a cartridge you replace and one from euro's is only fit for the bin.......


Sent from my iPhone using Tapatalk
 

turbopete

Senior Member
Joined
Feb 4, 2009
Messages
14,209
Reaction score
329
Age
46
Location
Spennymoor
Your Mercedes
2017 '17' Ford Mondeo 2.0TDCi ST Line X 180 (sorry)
on the subject of MAF's I looked at mine when I did the EGR mod. now ive found a similar looking 'sensor' in the plastic solid boost pipe, between the 2 rubber boost hoses that are between the intercooler and the inlet manifold. can anyone shed any light on what it does?
 

rpe2

Senior Member
Joined
Sep 25, 2006
Messages
2,866
Reaction score
3
Age
44
Location
Silchester
Your Mercedes
His: 2018 E220 d; Hers: 2016 SMAX
If anyone needs maf for an I6, let me know as I have a perfectly good one in my toolbox gathering dust.
 

Uncle Benz

Senior Member
Joined
Mar 31, 2006
Messages
3,837
Reaction score
2,767
Age
51
Location
West Sussex
Your Mercedes
Mainly Mercedes
on the subject of MAF's I looked at mine when I did the EGR mod. now ive found a similar looking 'sensor' in the plastic solid boost pipe, between the 2 rubber boost hoses that are between the intercooler and the inlet manifold. can anyone shed any light on what it does?

MAP, pressure sensor. Measures the boost pressure in the pipe. Rarely fail, but I have replaced a couple. Also seen the wires broken at the plug a few times.
 

turbopete

Senior Member
Joined
Feb 4, 2009
Messages
14,209
Reaction score
329
Age
46
Location
Spennymoor
Your Mercedes
2017 '17' Ford Mondeo 2.0TDCi ST Line X 180 (sorry)
i wondered what it was for and thought something boost pressure related. What are the symptoms if they fail or wires break, as a matter of interest (and for future reference!)
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
341
Age
87
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
With the MAF it has quite a fair range to adjust, it is not the MAF that turns the engine lamp on, it is the 02 sensor. The 02 sensor is the part that does the adjusting of the mixture based on the information sent by the MAF.

Once the 02 sensor has shifted too far from its stored values and range the engine lamp will come on. In most cases after a hard drive with the new MAF fitted, the engine lamp will go out on its own, but not always.
 

turbopete

Senior Member
Joined
Feb 4, 2009
Messages
14,209
Reaction score
329
Age
46
Location
Spennymoor
Your Mercedes
2017 '17' Ford Mondeo 2.0TDCi ST Line X 180 (sorry)
With the MAF it has quite a fair range to adjust, it is not the MAF that turns the engine lamp on, it is the 02 sensor. The 02 sensor is the part that does the adjusting of the mixture based on the information sent by the MAF.

Once the 02 sensor has shifted too far from its stored values and range the engine lamp will come on. In most cases after a hard drive with the new MAF fitted, the engine lamp will go out on its own, but not always.

I could be wrong on this Malcolm, but as the OP's car is a DIESEL, im not sure the O2 sensor is even fitted! I certainly dont have one on my diesel, and off the top of my head, i cant think of a diesel that DOES
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
341
Age
87
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
I could be wrong on this Malcolm, but as the OP's car is a DIESEL, im not sure the O2 sensor is even fitted! I certainly dont have one on my diesel, and off the top of my head, i cant think of a diesel that DOES

I know nothing about diesels Pete, then what ever controls the mixture on a d, as the MAF's are different on a diesel then maybe it does control it directly, I just do not know. :D
 

turbopete

Senior Member
Joined
Feb 4, 2009
Messages
14,209
Reaction score
329
Age
46
Location
Spennymoor
Your Mercedes
2017 '17' Ford Mondeo 2.0TDCi ST Line X 180 (sorry)
i believe that on modern diesels, its controlled (via the ECU) by signals from the MAF, Boost Pressure Sensor, Throttle Position Sensor, air temp sensor, Coolant temp sensor and probably a few other sensors, but i think that covers the main ones!
 
OP
G-a-r-y

G-a-r-y

Senior Member
Joined
Feb 7, 2006
Messages
557
Reaction score
4
Location
Bristol
Your Mercedes
S211 320 CDi, SLK 200 R171.
  • Thread Starter
  • Thread starter
  • #14
2004 320cdi maf?? they are cheaper than that from mb for the 320cdi straight 6! its only a cartridge you replace and one from euro's is only fit for the bin.......


Sent from my iPhone using Tapatalk

I've just checked with Mercedes before posting, on the old W210 the MAF was the cheaper cartridge. On the later W211 it comes complete, with 7% discount and plus VAT £221.
The Euro ones are genuine Bosch, identical as used by Mercedes. 30% extra off £151.
 

Uncle Benz

Senior Member
Joined
Mar 31, 2006
Messages
3,837
Reaction score
2,767
Age
51
Location
West Sussex
Your Mercedes
Mainly Mercedes
I could be wrong on this Malcolm, but as the OP's car is a DIESEL, im not sure the O2 sensor is even fitted! I certainly dont have one on my diesel, and off the top of my head, i cant think of a diesel that DOES

Would you care to have a little wager on that??
 

ThinkPad

Senior Member
Joined
Apr 16, 2012
Messages
1,034
Reaction score
109
Location
London
Your Mercedes
E W212; C W204
My diesel 320 cdi definitely has an o2 sensor.

Sent from my GT-N7100 using Tapatalk 4 Beta
 

AdamG

Senior Member
Joined
May 24, 2009
Messages
531
Reaction score
4
Location
Bromley, Kent
Your Mercedes
S320CDI (2003)
Gary, if you're think your maf sensor is not working check the wiring to the plug. On my w220 with the same engine the harness was cable tied to the plug as a strain relief. Unfortunately this doubling back setup kinked and fatigued the wires.

On the star test mine would not be in the green zone until I fixed the harness. It was only after I bought a new maf that I discovered it though:Oops:

Strangely I did not notice any difference before or after:confused:

Adam
 

turbopete

Senior Member
Joined
Feb 4, 2009
Messages
14,209
Reaction score
329
Age
46
Location
Spennymoor
Your Mercedes
2017 '17' Ford Mondeo 2.0TDCi ST Line X 180 (sorry)
Would you care to have a little wager on that??

which part? i am positive i cant think of a car ive worked on that has an O2 (lambda) sensor on the exhaust, and unless its attached to either the exhaust manifold or the turbo itself, ive had the ENTIRE exhaust off my car at some point or other so i can be 110% sure its not in the rest of the system!

whether later cars have them though, I cant be certain. like yourself, I can only draw on my own experiences to try to help people out with problems.

the fact ive never seen an O2 sensor on a diesel is the main reason why ive never been able to see the point in a diesel having CAT's etc!
 

Miffy

Senior Member
Joined
Sep 6, 2008
Messages
7,356
Reaction score
4
Location
Bromley, London
Your Mercedes
CLK 320 CAB Elegance C208
which part? i am positive i cant think of a car ive worked on that has an O2 (lambda) sensor on the exhaust, and unless its attached to either the exhaust manifold or the turbo itself, ive had the ENTIRE exhaust off my car at some point or other so i can be 110% sure its not in the rest of the system!

whether later cars have them though, I cant be certain. like yourself, I can only draw on my own experiences to try to help people out with problems.

the fact ive never seen an O2 sensor on a diesel is the main reason why ive never been able to see the point in a diesel having CAT's etc!

http://forums.mercedesclub.org.uk/showthread.php?t=72738
 

AIB understand your special Mercedes deserves a special insurance policy. We have a refreshing attitude to insuring high performance, modified, imported or classic and vintage cars and deal with the UK’s leading insurers. We offer discounts for length of ownership, where the vehicle is kept overnight and limiting the mileage and can also cater for those clients who need higher mileage and business use. To obtain a quotation please call the team on 02380 268351 or visit us atAIB Insurance
Top Bottom