AdBlue question…

[Kempy75]

2017 E220D Saloon

Evening, I have an AdBlue issue, which appears to be a common problem from what I’ve read on here, but I wanted to ask the below question to see if anyone knows the answer.

My error message states the engine won’t start in 475 miles, however it is reading the level of AdBlue in the tank correctly, as when I check the gauge it shows 4,400 miles left, and this rose from 3,800 after I topped up with 3.5ltrs yesterday, however the message still pops up each time I start the car and engine diagnostic light remains on

So the question is does anybody know which reading takes priority, the gauge showing I have over 4,000 miles, or the error message saying I only have 475 miles?

I’ve got a 400 mile trip in 2 days time so no time to get this looked at, and now nervous about possibly being stranded!

Any help appreciated

 

[markjay]

Welcome @Kempy75 .

The "Engine start not possible in xxx miles" message on cars equipped with the BlueTEC engines means that there's a fault with the AdBlue system, and not that there's not enough AdBlue in the tank.

The fault will typically be either a failed NOx sensor (there are two), or a faulty AdBlue pump. The only way to know what the fault actually is, is by reading the fault codes using MB STAR (or iCarsoft/Carly).

Unfortunately, AdBlue faults are usually expensive to fix.... and yes, the car will stop (or, rather, prevent you from starting the engine) when the warning mileage is reached - it's a regulatory requirement that is meant to stop people from driving around with inactive AdBlue systems.

Also, has the car been serviced recently by an MB dealer? Or had a recall done? The reason for asking is that here's a software update to the engine ECU that can cause NOx sensors failure.

 

[OneForTheRoad]

Just out of interest, what's the cars mileage at the moment?

 

[Kempy75]

Welcome @Kempy75 .

The "Engine start not possible in xxx miles" message on cars equipped with the BlueTEC engines means that there's a fault with the AdBlue system, and not that there's not enough AdBlue in the tank.

The fault will typically be either a failed NOx sensor (there are two), or a faulty AdBlue pump. The only way to know what the fault actually is, is by reading the fault codes using MB STAR (or iCarsoft/Carly).

Unfortunately, AdBlue faults are usually expensive to fix.... and yes, the car will stop (or, rather, prevent you from starting the engine) when the warning mileage is reached - it's a regulatory requirement that is meant to stop people from driving around with inactive AdBlue systems.

Also, has the car been serviced recently by an MB dealer? Or had a recall done? The reason for asking is that here's a software update to the engine ECU that can cause NOx sensors failure.

Thanks for the reply, which unfortunately confirms what I didn’t want to hear!

Last service was independent by the dealers I purchased from, and prior to that was also
non-MB, and no recall that I’m aware of

Looks like a tentatively driven trip coming up and then my wallet being raided when I get back, joy!

 

[Kempy75]

Just out of interest, what's the cars mileage at the moment?

50.6k

The trigger for this happening, coincidental or not, was literally just after filling up after being pretty low on fuel. Unsure if that has any bearing or not though

 

[OneForTheRoad]

Current recalls | Mercedes-Benz

Find out about the latest recalls and see if your Mercedes-Benz is affected.

www.mercedes-benz.co.uk

Put your vin in here , it'll tell you the current state of any recalls.

I've watched videos of the ad blue system havin readaptation by a hand held device, it worked and the 500 mile warning went away , failing that 2 new nox sensors and a software update can be around £1500 , same with the ad blue tank .

 

[Kempy75]

Current recalls | Mercedes-Benz

Find out about the latest recalls and see if your Mercedes-Benz is affected.

www.mercedes-benz.co.uk

Put your vin in here , it'll tell you the current state of any recalls.

I've watched videos of the ad blue system havin readaptation by a hand held device, it worked and the 500 mile warning went away , failing that 2 new nox sensors and a software update can be around £1500 , same with the ad blue tank .

Thanks for that, will have a check later

The first resolution sounds much more appealing!