Erratic warning light on C220d

[Wynpar]

I wonder if anybody can help solve a problem I might or might not have?

My 2016 C220d has been acting strangely lately.The yellow engine warning light comes on every now and then and then a few trips later just disappears .When the light is on there is no loss of power or added exhaust smoke ,in fact nothing changes.

I’ve used my OMDII scanner on it and the code it produces when the light is on is P220F which I think relates to a Nox sensor issue but surely the Nox sensor is either US or not.

My local merc garage have told me that it will cost £139 just to plug the car onto the computer to look for the issue and then to change the sensors ( if 2 are required) will be in excess of £450 each plus Labour. My fear is that they will just go the lazy route and change both and I end up with a mega bill .

Has anyone else experienced this intermittent problem and if so how did the resolve.

Many thanks all in advance

 

[Blobcat]

Hello and welcome,

Engine warning lights are unfortunately very common with Euro 6 diesels - lots of threads on the forum about it. Normally they come on and stay on, but it will be part of the emissions equipment - AdBlue - NOX Sensors and DPF related

 

[Wynpar]

Thanks for this. Just wondering if it’s something that I should take up with Merc HQ if it’s a common issue, I’m guessing I’m out of warranty on this fault by now.
I’ve just had the very latest service update done on the car and the yellow light came on shortly after it …again so the update hasn’t solved it.

The other thing I’m wondering is what damage am I potentially doing when the light is on .

 

[Blobcat]

You're 2 years out of warranty unfortunately - Merc can charge many £K's to fix the issue

I'd recommend you update your profile with your location so that members can recommend a Mercedes Indie - they have the Mercedes specific diagnostic equipment and the expertise to resolve the problem.

There's been quite a few versions of NOX sensor and engine management software updates - have you had any updates from Mercedes? There's been quite a few threads where members have had engine warning light issues following software updates by Mercedes that then leads to requiring new NOX sensors. Please have a search and read on the forum - forewarned is forearmed

 

[Wynpar]

You're 2 years out of warranty unfortunately - Merc can charge many £K's to fix the issue

I'd recommend you update your profile with your location so that members can recommend a Mercedes Indie - they have the Mercedes specific diagnostic equipment and the expertise to resolve the problem.

There's been quite a few versions of NOX sensor and engine management software updates - have you had any updates from Mercedes? There's been quite a few threads where members have had engine warning light issues following software updates by Mercedes that then leads to requiring new NOX sensors. Please have a search and read on the forum - forewarned is forearmed

Yes I’ve just had my car updated in the Merc garage close to where I live ( Anglesey north wales ) .
Although the light wasn’t on when it when in for the update it came on a week later .I would have though the Merc garage would have picked up an issue whilst updating but maybe not .

 

[Blobcat]

Yes I’ve just had my car updated in the Merc garage close to where I live ( Anglesey north wales ) .
Although the light wasn’t on when it when in for the update it came on a week later .I would have though the Merc garage would have picked up an issue whilst updating but maybe not .

I'd read the forum then take it back and get them to fix it - best of luck

 

[Steve@Avantgarde]

I wonder if anybody can help solve a problem I might or might not have?

My 2016 C220d has been acting strangely lately.The yellow engine warning light comes on every now and then and then a few trips later just disappears .When the light is on there is no loss of power or added exhaust smoke ,in fact nothing changes.

I’ve used my OMDII scanner on it and the code it produces when the light is on is P220F which I think relates to a Nox sensor issue but surely the Nox sensor is either US or not.

My local merc garage have told me that it will cost £139 just to plug the car onto the computer to look for the issue and then to change the sensors ( if 2 are required) will be in excess of £450 each plus Labour. My fear is that they will just go the lazy route and change both and I end up with a mega bill .

Has anyone else experienced this intermittent problem and if so how did the resolve.

Many thanks all in advance

NOx sensors are an absolute ball ache at the moment. Parts are backorder, you have to replace them as pairs and match them in with new software, changing the datacard in some instances.

The light will only come on and off during a fill time sequence or a regeneration sequence which parameters cannot be met. Essentially that system is its own controller, it just works in tandem with the engine management.

Your indie is right, they are expensive. I Dont quite agree with the cost the cost of diagnosis, I wouldnt charge that much, but remember the Xentry online equipment is expensive, its their investment and is nothing like the cheap DTC reader you have. You are also paying for their knowledge and expertise and that will come at a premium over other garages, the advantage being, that you will get the right diagnosis, and first time fix.

 

[Wynpar]

NOx sensors are an absolute ball ache at the moment. Parts are backorder, you have to replace them as pairs and match them in with new software, changing the datacard in some instances.

The light will only come on and off during a fill time sequence or a regeneration sequence which parameters cannot be met. Essentially that system is its own controller, it just works in tandem with the engine management.

Your indie is right, they are expensive. I Dont quite agree with the cost the cost of diagnosis, I wouldnt charge that much, but remember the Xentry online equipment is expensive, its their investment and is nothing like the cheap DTC reader you have. You are also paying for their knowledge and expertise and that will come at a premium over other garages, the advantage being, that you will get the right diagnosis, and first time fix.

Thanks for this very useful info .
My quote was from a main dealer( Inchcape) what do you think a reasonable Indie quote should look like ?

also does running it in this on off fashion do damage ?

thank in advance
wyn

 

[onefortheroad]

How many miles has the car done , out of interest ?

 

[Steve@Avantgarde]

Thanks for this very useful info .
My quote was from a main dealer( Inchcape) what do you think a reasonable Indie quote should look like ?

also does running it in this on off fashion do damage ?

thank in advance
wyn

Diag fee - 0.5 hour of labour at their own rate.
NOx - Price of these range from £195-£450 per sensor depending on which ones are fitted to your vehicle.
Labour to fit Nox and carry out software update - 1.5 hour x their labour rate.

Then add the vodka and tonic.