NOx - Understanding How Many Of Us

[rayaans]

2015 W205 C200 - gearbox went into limp mode and wouldn't change gears unless done manually. Turned on and off and was back to normal again

Ran the codes at home and the only one came back which was nox sensor on bank 1 sporadic failure

Left it and kept it going for about 6 months and now the EML is on. Ran the codes again. Still a sporadic failure of bank 1 nox sensor.

It's under warranty so MB Huddersfield are going to look at it next week. Will report back in due course

 

[Moviestar]

Hi
all got an ML350 and had the NOx sensor go so got it replaced at my local Non Mercedes dealer now about 3,000 mile later its started coming up with a orange engine warning light with code P229F. So think the NOx sensor has gone again. I assume it was a Merc part so hopefully will change it but will probably have to pay for the labor? Was looking to see if there is another alternative i.e code out? anybody tried that?

 

[rf065]

Was looking to see if there is another alternative i.e code out? anybody tried that?

Yes, no nox sensor issues or adblue warnings anymore. Only regret is how much money I had to spend fixing these problems only to see them return again later. Should have done it much sooner.

 

[W1ghty]

2017 C200 petrol.
I bought approved used, and was comforted by the receipts for the recent dealer service, including NOx sensor. EML came on on the 200 mile journey home :-( My own diagnostic kit told me it was the nox sensor.
Supplying dealer wasn't practical for me to return it to, so embraced the network and had the misfortune to use MB Dartford, where I got a bill for £500. They refused to give the keys back until I paid. Very unhelpful attitude. Might also add it too 2 months to get the part.
I paid up, went to MB "main" customer services, and they instructed the issue of a refund- which took over 2-weeks to arrive.
First and last encounter with Dartford..
Touching wood, in nearly a year since, it's been ok.
Now that the warranty has expired, I'll be doing all my own work where I can, and using my local indy (Wright-tech Sidcup, whom I've had good service from previously) where I can't.

Approved used should have covered that sensor on the Tier 1 years warranty

 

[ambjoinery]

I've had my car serviced since 2016,to date,at a MB Authorised workshop. When I collected my car after the August 2021 service, I was told the nox diesel software update had been done. To say I was unhappy is a understatement! I spoke to the dealer director, who I told I didn't ask, was not made aware of this update. His response was that I'd phoned to ask for the update to be done. After telling him "this is no way to treat a customer " ,and that I'd be approximately £300. Per year out of pocket with the decreased mpg, he agreed to give me a £300. Credit to spend on any products at his dealership. I.e parts, servicing, mot, etc.

 

[rayaans]

Following on from my previous post, it was indeed the nox sensor and it'll be replaced under warranty. Unfortunately not sure when as they don't have a date for the sensor arriving

Car drives fine so I'll just wait it out unless getting closer to MOT time

 

[rayaans]

Update - just had a call from the dealer that the NOX sensor has been delivered to them and that they can fit it in 2 weeks. Fingers crossed but looks like they may not have a massive delay like people think

 

[Johnr1975]

Just had eml light come on yesterday. Took it to a local indie and it's coming up codes for Nox sensor.
Booked into mb dealer for 2nd of march .
Car is a c220 w205 2015 plate 47000 miles.
Said it will be replaced under warranty

 

[cws196]

Having read through the above, I'm still unsure (or may have missed it) if the Nox sensor replacement was a wider recall even if the Nox faults hadn't appeared OR if they were only replaced FOC as/when they went wrong?

 

[rf065]

Having read through the above, I'm still unsure (or may have missed it) if the Nox sensor replacement was a wider recall even if the Nox faults hadn't appeared OR if they were only replaced FOC as/when they went wrong?

Or, in my case, Mercedes made me pay for mine. They were not even interested in any goodwill.

 

[rayaans]

Mine was replaced by the dealer 2 weeks ago. No issues since. Might just be in my head but seems to rev out a lot better

 

[FlyBoyRez]

Hello All,

Like many of you I've had an intermittent Check engine light / Engine Management Light on my 2017 S213 e220d. Codes were read and it is the P30063F NOx sensor open circuit and P300640 NOx sensor short. Local indy garage has reached out to MB for spares, pars unavailable nationwide, so on back order and I'll go back in when available.

Car runs OK, can be a little sluggish off the line which can make for interesting times at roundabouts / junctions...

Price quoted for the sensor is £550! Wondering if I should take it in to MB themselves? I've bought the car secondhand, ex lease car I think, no MB warranty on it as far as I can work out. My local dealership is in Derby, never used them before.

Is £550 the current price for these things? Should I go to the daler to get it done? I read others get it replaced for free... any hope or bob hope of getting this?

Thanks in advance!

 

[rf065]

In my experience, the nox sensors issue is only the first, after you've paid through the nose to fix that problem, the adblue problems will start and the costs rise even higher.

 

[Slartibartfast]

....
Price quoted for the sensor is £550! Wondering if I should take it in to MB themselves? I've bought the car secondhand, ex lease car I think, no MB warranty on it as far as I can work out. My local dealership is in Derby, never used them before.
Is £550 the current price for these things? Should I go to the daler to get it done? I read others get it replaced for free... any hope or bob hope of getting this?

Thanks in advance!

£550 to £600 sounds about right for a Nox sensor including fitting and coding. In my experience the Main Dealer and Specialists charge around the same. There are 2 x Nox sensors and when one goes wrong it is usual for the other to fail within a short time (maybe days, weeks or months).

I managed to get both my faulty Nox sensors replaced FOC by Main Dealer. My car has full Main Dealer service history and they had just completed the Diesel software update so that may have had some bearing on the offer of free replacements.

 

[merc estate]

Good luck, keep us updated

 

[MSG2004]

I hope this helps.
Boguht a brand new GLE/250 in mid 2016
One driver since new adn I still have the car.
Car has now covered about 19k miles
Just after the warranty expired 2 weeks I think and
with around 12k on the clock and FSH as per MB
service sheet, the day after the 3rd service, driving back from the hospital
about 10 miles away near to home, eML came on and car was nor limp mode but
very sluggish. Almost got caught out of the roundabout as there was a mass of hesitation
when I tried to move onto the roundabout. Spoke to the dealer that serviced the car the main dealer, credit to them they said to bring it back the next day and told me a couple of hours later Noc failed. I cited this as not great as car FSH and little miles and I had read about Nox
being a problem. The last looking after me told me to leave it with her and rang the next day to say MB
agreed FoC fix but it was the one sensor.

This is my first diesel car ever as I could not justify the cost of the AMG, a brand new car that is petrol
and all other cars were diesel at the time.

Today, returning from the hospital the EML came on, and then a restart made the EML go away. I love the size of the car etc
but not the diesel engine. It does not make sense to sell it as it's still practically brand new on the inside as we have other cars
but in my opinion MB should not make it a hit/miss who pays, who argues/worries or not as its a design fault IMO

(I've started a thread re EML)

 

[Chris9370]

Hi All,

I have a 2019 Vito 114 (w447), been great so far but now have Nox/Adblue problems.

Was getting fault code advising lost communication with rear sensor but it wasn’t showing check engine light until a few weeks ago. This changed then to the countdown in miles until won’t start (500 miles I think) and a poor Adblue quality message which I think could be related to the sensor now completely knackered?

I ordered an aftermarket sensor as had heard decent reviews about the company and fitted it this afternoon , after using my Xentry to code in the sensor and trying unsuccessfully to reset the ‘remaining miles’ message I decided to take it for a drive.

I could feel instantly the performance was back and felt really sprightly to drive.

Parked up, read codes again with Xentry and the poor Adblue quality message has disappeared however I cannot seem to delete the ‘remaining distance’ warning.

I also have a Carly but this won’t do it either, I cannot use my Xentry version as it’s wanting to connect to the main server to recode?

Does anyone know any other scanners that will clear the countdown or if a longer drive will do it? I’ve only got 170 miles left to go as had to use it to drive to a course yesterday.

Thanks, Chris.

 

[elite_504]

So after 14 months and 4000 miles, the EML came back on.
I called MB Dartford to see what the warranty options were, only to find out they were closed whilst the dealership was being taken over and the staff were in training who were being tupe's over. They did let me book the car in for this passed week though.

I thought it would be the usual, frustrating two-visit affair; visit one for them to say "It's the NOx sensor", which I already knew, and then the second visit months later for fitting when one was back in stock. In all fairness when I went to collect the car it had been done as they actually had one in stock. Being a 4-cylinder petrol, it only has one sensor and I think it's the diesels that are usually eating up the nations supply.

Two year warranty on parts meant there was no charge, thankfully.

 

[Deeman23]

Just purchased a 2018 C220d Coupe from MB @MK on the drive home the engine light came on so managed to get home and called breakdown who attended next morning.
Yes you’ve guessed it’s the Nox senso, after googling the issue I wondered if I should have chosen a different car but I must admit the Coupe is a nice drive in a reasonable condition although it does need a couple of issues resolved.
Contacted my local MB dealership which I had used before with other MB cars, they booked me in a week later, on the day they replaced the Nox sensor under Warrant, so far now all seems well.
After reading the issues if I keep the car after expiry of the Warranty I will pay for an extended Warranty as a peace of mind option.
Otherwise the car looks and drive well sat on a good set of 20” wheels.

 

[MattGLC]

My 2020 GLC visited Mercedes at Bury St Edmunds yesterday after the EML light came on about a week ago. Diagnosed as the downstream NOx sensor. Awaiting the part, no idea how long it’ll be until it’ll be fixed though. :/

Car has done about 26,000 miles and is still under warranty (thankfully).