P13E7FD AdBlue level is low - Cannot measure fluid level message

[CabrioChap]

My 2018 E Class Cabriolet (46k miles) has a 10L AdBlue tank and I've always been careful to top it up with 5L with some anti-crystal additive as soon as the warning indicator has been displayed.

This week it decided it couldn't read the level anymore. P13E7FD fault code, which comes back as soon as it is cleared.

I dropped the tank, emptied out 6l of AdBlue, popped a boroscope in to see if there was anything obviously wrong. I could see some red flecks around the place and on the white mesh at the base of the tank, but nothing obviously wrong. I was expecting crystals or something.. I flushed it with AdBlue, filled with 4L of new AdBlue and connected it back up..

No joy.

Annoyingly if I clear the code, it accurately shows 4L of fluid on the dash display for a few seconds, then goes back to 'Cannot measure fluid level'.

Looks like a new tank (with pump - which I don't need as there is no fault with that) is £1300.
Used tank of similar vintage is £250 on eBay.. so I'm trying that first.

Thought I would share just in case anyone else thinks they might be lucky and will get away with 'cleaning' the tank to fix a level sensor fault.

 

[rf065]

Thought I would share just in case anyone else thinks they might be lucky and will get away with 'cleaning' the tank to fix a level sensor fault.

Been there 3 years ago, remap and adblue delete and not one problem since. Wasted approx £1000 on Nox sensors before the "cannot measure level" warning. Should just have remapped first time and saved myself time and money.

 

[pcthrillrider2]

Been there 3 years ago, remap and adblue delete and not one problem since. Wasted approx £1000 on Nox sensors before the "cannot measure level" warning. Should just have remapped first time and saved myself time and money.

does it pass an mot test?

 

[rf065]

Passed the last 3 without any problems.

 

[markjay]

Setting aside the AdBlue Delete's merits (or lack of), you may be able to resolve the current issue with the AdBlue level sensor by replacing the AdBlue tank with a second hand unit off eBay, however AdBlue problems tend to be both frequent and costly to repair, my advice would be to fix the car than trade it in before the next AdBlue issue presents itself. Which is a shame, really, because these are otherwise great cars.

 

[ALFAitalia]

does it pass an mot test?

Not part of the test.....yet! Looking like it might be soon though.
It is illegal to take a car with a any factory fitted emissions equipment removed or modified though....£1000 fine.....and technically voids you insurance .......but before you say it, yes I've never heard of anyone being convicted or having an insurance claim refused either.
Having read lots of the ADblue disaster stories on here and can completely understand the temptation to map it out. The whole system is just not fit for purpose. Over on the Jaguar XF forum I've never seen a single ADblue horror story so it can be done....just not by Mercedes it would seem!!

 

[CabrioChap]

To my surprise and delight, a replacement tank from eBay has fixed the issue.

We’ll see how long for though.

 

[Ithinkimgoingcrazy]

Setting aside the AdBlue Delete's merits (or lack of), you may be able to resolve the current issue with the AdBlue level sensor by replacing the AdBlue tank with a second hand unit off eBay, however AdBlue problems tend to be both frequent and costly to repair, my advice would be to fix the car than trade it in before the next AdBlue issue presents itself. Which is a shame, really, because these are otherwise great cars.

Hello dear Markjay, where can I find you? I am desperate to receive some help from you... Thanks in advice!