Hi all
New to for forum and after some help.
My 2017 G31 520d has been in to Marshall Grimsby today for the EGR Cooler recall.
took the car in this morning at 8 am and by 12:30 got a call to say all done.
Went to collect the car and as soon as I unlock it "Ad blue system failure " is on the information screen.
obviously I go back inside and after a few panicked "never seen that before " they take the car back into the garage.
15 mins later a chap turns up saying it's completely unrelated and produces a print out report showing the car recorded Active tank SCR Delivery module short to ground although the mileage recorded against the fault is the car's current mileage not a previous mileage.
I said it can't be that unrelated, its never displayed the failure message before and clearly the ad blue goes in the exhaust. Now I did previously add Wynns cleaner when the float got stuck with crystallisation but I've definitely not had any failure message.
At this point the guy says ad blue is added to the diesel at the intlet manifold and we to and fro between this and me saying it's irrelevant, the car came in with no faults on the dash and its occurred whilst in their care.
I've left it with to have another look tomorrow.
So thoughts please??

 

Something could just be clogged (or knocked loose). Have them diagnose it.