Presumabily NOX Sensors - ML350 Bluetek 2012 ADBLUE

Lucio

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Joined
Nov 21, 2019
Messages
8
Location
Windsor
Car
ML350 bluetec
Hi All

I have been struggling with an issue for the last few week with my wife's ML, as the MIL light switched on and the electronic display is warning that the car won't start in 400 miles!

I have searched the web but not a lot of specifics on this topic to help and guide me to a solution.

I have used a MaxiScan MS509 scanner and managed to read two generic codes:
  1. P2BA8
  2. P2BAD
I have managed to follow some documentation on line and I have identified both sensors, removed and cleaned them, and made sure all electrical connections were intact. I have reset the codes, but no success.

By the way, the AdBlue tank has been refilled and fuses checked!

Whilst doing this work, I did a couple of tests by disconnecting each of the sensor's computer from the car, and run the scanner again and read the following codes:
  1. U029E (Sensor furthest from the engine)
  2. U029D (Sensor closest to the engine)
I also identified the part numbers for the sensors (phots included).
  1. A0009053603 (Sensor furthest from the engine)
  2. A0009053503 (Sensor closest to the engine)
I have some questions before I bite the bullet and buy the sensors.
  1. Am I right to assume that this is the fault - sensor?
  2. I read that I need to change both sensors - is this correct?
  3. Do I need to re-start/program the new sensors or is this just a straight swap?
  4. Is there a cheap scan that I can use to reprogram the sensors after the swap?
  5. Is it worth buying it second hand or like I said "bite the bullet" and buy 2 new sensors?
  6. Do you have a supplier to recommend that has a less expensive price pls?
Many Thanks

Lucio

UNADJUSTEDNONRAW_thumb_120b.jpg UNADJUSTEDNONRAW_thumb_120c.jpg
 

Tramper

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Feb 2, 2019
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148
Location
Essex
Car
E Class
Had the same problem with my W212. Both Nox sensors replaced sorted it.
 

tonysurf

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May 25, 2009
Messages
115
Location
SE London
Car
E Class Cab
Does the car have MB service history, my NOX sensors registered the same problem as yours, MB replaced both under goodwill warranty. Saw the invoice price as around £750 lucky escape.
 
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Lucio

New Member
Joined
Nov 21, 2019
Messages
8
Location
Windsor
Car
ML350 bluetec
Hi all

thank you, no service history!

@Tramper did you just swap or did you have to reset it also?

Thanks

Lucio
 
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Lucio

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Nov 21, 2019
Messages
8
Location
Windsor
Car
ML350 bluetec

Abb

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Was it a straight forward job to replace them? If so, seems like a bargain you have got yourself there. There are several posts on here where MB have charged/quoted anywhere between £1K-£2K to have both Nox sensors replaced!
 

Seth119

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Joined
Feb 24, 2020
Messages
6
Location
cleveland
Car
e class 212 2.1 diesel amg
Hi help needed,

i replaced the front NOX sensor (upstream) went to clear the code now the down stream one is displaying a code on a merc e class 2015 250 blutec. the question i have is the rear sensor the same part as the front one - or different? as i haven't been back under the car. Also MERC dealership say replacing both with none genuine parts wont work as they need to be remapped?

It was a straight forward enough job replacing the upstream one, i installed a new one from Amazon not genuine MB part.

What part do i require for the down stream one is it a totally different part number? and if I now change both will they work before i spend another £ 190 pound.

MB dealership wanted £1200 to replace both and clear the fault. nox2.jpg nox1.jpg
 

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BlackC55

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E55K SL500 E300Hybrid E250X3 Viano C55 E450Cab A180 Smart 44 Brabus
Hi help needed,

i replaced the front NOX sensor (upstream) went to clear the code now the down stream one is displaying a code on a merc e class 2015 250 blutec. the question i have is the rear sensor the same part as the front one - or different? as i haven't been back under the car. Also MERC dealership say replacing both with none genuine parts wont work as they need to be remapped?

It was a straight forward enough job replacing the upstream one, i installed a new one from Amazon not genuine MB part.

What part do i require for the down stream one is it a totally different part number? and if I now change both will they work before i spend another £ 190 pound.

MB dealership wanted £1200 to replace both and clear the fault. View attachment 92707 View attachment 92709

quite often we have to replace both at the same time and have a code added to the data card from Mercedes when we order them so they are probably right.

Natacha
 

Seth119

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Feb 24, 2020
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cleveland
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e class 212 2.1 diesel amg
quite often we have to replace both at the same time and have a code added to the data card from Mercedes when we order them so they are probably right.

Natacha
Is the rear the same part sensor as the front or different? Why would the data card need updating? If exchanging one sensor for another? Thanks
 

BlackC55

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Is the rear the same part sensor as the front or different? Why would the data card need updating? If exchanging one sensor for another? Thanks

they are usually the same part number. Honestly couldn't tell you the reason why (just a mere receptionist) but I know some of them (not all) we have to order both sensors at the same time and they have to be coded together
 
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Lucio

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Nov 21, 2019
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Windsor
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ML350 bluetec
Is the rear the same part sensor as the front or different? Why would the data card need updating? If exchanging one sensor for another? Thanks

Hi Seth119

If you read my post at the top I have posted pictures of both sensors including the circuitry. They Do have 2 different part numbers:
  1. A0009053603 (Sensor furthest from the engine)
  2. A0009053503 (Sensor closest to the engine)
They might be identical but they perform different tasks.

I have used an Autel scanner to “retrain” the sensors and to remove/clear the fault.

Not a big deal. I have also posted the link to the suppliers I have used.

Lucio
 

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