NOx - Understanding How Many Of Us

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Bought a 62 Plate Merc ML at the beginning of May. A week ago I got message something like "1,700 miles before AdBlue runs out". I filled AdBlue to the brim. EML light still on. Tried all the tricks on the web to turn it off. No Go. Next day "600 miles engine won't restart". Took it to MB Oxford today. They are getting 2 Nox sensors for the end of the week. They want £1,871.52. and will have to remove exhaust. 3.8 hours
 
Bought a 62 Plate Merc ML at the beginning of May. A week ago I got message something like "1,700 miles before AdBlue runs out". I filled AdBlue to the brim. EML light still on. Tried all the tricks on the web to turn it off. No Go. Next day "600 miles engine won't restart". Took it to MB Oxford today. They are getting 2 Nox sensors for the end of the week. They want £1,871.52. and will have to remove exhaust. 3.8 hours

Lets hope your not footing the bill 😬
 
Find it both galling and disgusting the way that MB are treating many owners. Some people are having to foot £1500-2000 invoices - which seems unfair.

Shame that all affected owners cannot somehow be unified in any type of litigation action - my guess is that 10.000s are affected, if not 100,000s.
 
Find it both galling and disgusting the way that MB are treating many owners. Some people are having to foot £1500-2000 invoices - which seems unfair.

Shame that all affected owners cannot somehow be unified in any type of litigation action - my guess is that 10.000s are affected, if not 100,000s.
Bought a 62 Plate Merc ML at the beginning of May. A week ago I got message something like "1,700 miles before AdBlue runs out". I filled AdBlue to the brim. EML light still on. Tried all the tricks on the web to turn it off. No Go. Next day "600 miles engine won't restart". Took it to MB Oxford today. They are getting 2 Nox sensors for the end of the week. They want £1,871.52. and will have to remove exhaust. 3.8 hours
same problem and MB Chelsea quotes around 900. Why such a big difference? Quite annoying as some forum said some MD replaced them free. Youtube video showed cleaning the sensors probe may solve the problem. Like to give it a trial.
 
Just read this thread and wonder if there is anything that I can do to prevent my car from having Nox sensor problems?
Its a 2015 E350 Bluetec with 46k miles, run only on V Power diesel and serviced by excellent indy each year as per schedule
 
How about gang ? Putting up the names of the garages that have been helpful with this problem and fixed free of charge ? Lets give everybody else a chance with getting this done for free :thumb:
 
Bought a 62 Plate Merc ML at the beginning of May. A week ago I got message something like "1,700 miles before AdBlue runs out". I filled AdBlue to the brim. EML light still on. Tried all the tricks on the web to turn it off. No Go. Next day "600 miles engine won't restart". Took it to MB Oxford today. They are getting 2 Nox sensors for the end of the week. They want £1,871.52. and will have to remove exhaust. 3.8 hours
Does anyone have the part numbers for the nox sensors and the adblue tank
Mercedes want £1800+ to sort this problem
 
It’s interesting reading about everyones experience. Despite living in Berkshire, I was recommended Basingstoke MB by a good friend. I’ve always taken my cars there for all work/services and they’ve been great.

When I picked up my wife’s car up after having the sensors replaced, the service guy said they had completed three cars that day. He said it was a common fault and as a consequence, MB were replacing them for free,
 
Mercedes Quote with Part Numbers for replacing Nox Sensors on 2012 ML250 TOTAL £ 1,620.96

Labour 3.8 HOURS £385.70

MA166 520 02 23 NOISE CAPSULE £ 88.50

MA000 905 35 03 104A05 NOX SENSOR £417.00

MA202 490 08 41 108C05 CLAMP £ 10.00

MA000 492 08 81 101D04C SEAL RING £ 5.75

MA000 492 08 81 101D04C SEAL RING £ 5.75

MA202 490 08 41 108C05 CLAMP £ 10.00

MN910143 008 006 102D06C HEXALOBULAR BOL £ 1.40

MN910143 008 006 102D06C HEXALOBULAR BOL £ 1.40

MA000 905 36 03 104A13 NOX SENSOR £379.00

MA002 995 49 02 107E09 PIPECLAMP F EXH £ 46.30

NET £1,350.80
VAT £ 270.16
TOTAL £ 1,620.96
 
Ouch.

Looks like they at least discounted the labour.

Useful post as clearly shows the MB part cost rate versus other potential suppliers, if members need to self fund.
 
Hi Guys, my 03/2015 CLS 220d BlueTec has been throwing the EML light intermittently since the end of March. A scan with Snap-on Solus Ultra is showing error codes P220F77, P229F92, P22A021, P229F91 and P229F85. Up to now I've just bought a £10 scanner off ebay and been clearing the code (P2200), happens about once every third journey, but I think it's time I got it sorted. Car has FMBSH, 45,000 miles, last serviced in November when I was told a software update was performed, also has a current service plan. I have 2 questions, number one, is it worth trying the dealers (MB Stoke) or should I go straight to the local indie (Merx, also in Stoke) and secondly if I go the dealer route how do I handle it? Do I go in humble, plead poverty and ask if any goodwill is available or do I go in informing them that I am aware that their is a serious problem with the Nox sensors and that they are being replaced FoC ?
As an aside can anyone confirm or deny if any coding is required if I were to replace the offending sensor myself?
Thanks in advance guys, as always your advice is much appreciated.
Cheers
Steve
 
Hi Steve

Most definitely try the dealer route given the history with vehicle.

MB are tightening up on goodwill - cannot see why but will no doubt be a cost avoidance plan. Will be interesting to see if the "UK class actionS" reap any solace for UK consumers.

Understand that the majority of indies struggle to code after replacement parts. Note there was recently a backlog on these parts. This should give a clue over how many were/are being replaced globally.

You may well be handy with a spanner but would advise approach dealer in first instance. Sure that Merx are competent but if MB complete FOC then a much better outcome.

There are literally 1000s of UK MB consumers that have had issues whilst MB contribution to cost has been massively inconsistent.
 
I have a 2015 petrol C200, only do about 6000 miles per year and already had NOx sensors changed 3 times. EML came on yesterday, I’d put money on it that it’s the NOx sensors again. Waiting on Mercedes dealer phoning me back to answer if it’s something they’ll fix again out of goodwill as it’s clearly a defect, but booked into my own garage to check the fault next week, just in case it’s something else.
 
Most of these exhaust [post combustion ] emission treatments /sensors work best when the exhaust has reached full operating temperature- short journeys with lots of exhaust water condensate or fuel mixture enrichment tends to shorten their life :(
 
I have a 2015 petrol C200, only do about 6000 miles per year and already had NOx sensors changed 3 times. EML came on yesterday, I’d put money on it that it’s the NOx sensors again. Waiting on Mercedes dealer phoning me back to answer if it’s something they’ll fix again out of goodwill as it’s clearly a defect, but booked into my own garage to check the fault next week, just in case it’s something else.

You are not alone. Heard of multiple failures. 3x on one vehicle is not uncommon.

Generally, MB stand by any repairs for a year, Wonder what happens with those vehicles that fail, eg 18months, after authorised repairs.
 
I have a 2016 C250d and the engine light came on, using my scanner it flagged both NOX sensors, called the Mercedes dealer who I have a service contract with and they said they would need to run diagnostic at the cost of £192 for the first hour and if it was indeed the sensors they would write off to mercedes head office and they would decide if the will replace free of charge or contribute to the cost and the diagnostic fee would be covered. How do they decide who gets it free and who pays as I have read people who are out of warranty like myself having them replaced free and some who are footing the bill. It’s a joke of a policy. Either the customer pays or they decide that it’s mercedes who are accepting responsibility.
 
Hi all, just a thought on the NOX sensor issue, I have a 2011 CLS350 V6 petrol, only bought it a couple of weeks back from a Indy dealer, first long trip out EML came on yellow, OBD scanner throws up code P0162 O2 sensor bank 2 sensor 3, led to believe its the rear sensor past the back box!? not had chance to get under the car yet as i'm on hols, My thought process goes..... is there a way of remapping this sensor out completely??, I was thinking along the lines of AM exhaust without back boxes, it would most likely work out cheaper in the long run for those out of warranty than keep replacing the rear sensor(seems to be the most common one to fail), would appreciate any feedback and thoughts!
 
I have a 2016 C250d and the engine light came on, using my scanner it flagged both NOX sensors, called the Mercedes dealer who I have a service contract with and they said they would need to run diagnostic at the cost of £192 for the first hour and if it was indeed the sensors they would write off to mercedes head office and they would decide if the will replace free of charge or contribute to the cost and the diagnostic fee would be covered. How do they decide who gets it free and who pays as I have read people who are out of warranty like myself having them replaced free and some who are footing the bill. It’s a joke of a policy. Either the customer pays or they decide that it’s mercedes who are accepting responsibility.
If you have a service contract with a main dealer, I would like to think that MB will be amenable to a contribution to the replacement cost. If the car has always been serviced by MB then hopefully the contribution would be major.

I think it’s a bit naughty having to pay through the nose for a diagnostic check which does no more than confirm what you know: a known Mercedes fault. But it seems to be the only way to get them thinking about it. And of course there’s always the risk that they’ll refuse to provide any goodwill, so the diagnostic check cost is wasted. It’s certainly a quandary and one that I’m having to consider yet again.
 
You are not alone. Heard of multiple failures. 3x on one vehicle is not uncommon.

Generally, MB stand by any repairs for a year, Wonder what happens with those vehicles that fail, eg 18months, after authorised repairs.
I’m soon to find out. I had NOx sensors replaced about 23 months ago and again the EML has come on (P2214 - NOx Sensor Circuit Range/Performance Bank 2) MB parts carry a 24 month warranty so I would hope to get the parts free if nothing else.
 
Find it both galling and disgusting the way that MB are treating many owners. Some people are having to foot £1500-2000 invoices - which seems unfair.

Shame that all affected owners cannot somehow be unified in any type of litigation action - my guess is that 10.000s are affected, if not 100,000s.
Would it make useful sense to create a register of owners and their cars that have been subject to NOx sensor failures on this platform? Has anybody identified a particular model/engine type that is most at risk? There are already other registers on here.
Just a couple of thoughts.
 

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