I just bought a 2016 535D (I know this isF30 post but there was no N57 community in F10post) and as soon as I got on the highway the CEL was on. It wasn't on during the test drive, so it literally came on after I signed the papers. It had 51k miles and I bought it from a used car lot. It was a BMW fleet vehicle and then only had one owner. The good news is that I have 36k mile warranty.
I dropped it off at the shop and although I was expecting a simple "read the code" error, they fed me some bs about how they still had to diagnose it. So they said that the diesel exhaust fluid pump had failed. I am BRAND new to diesels and have not even heard of that. The car has been running fine (I have been driving it regularly and put probably a little under 500 miles on it). Now we are waiting for the part to come in. So what exactly is going on here? Should I be worried? Again, I'm brand new to diesels so I really have no idea.
And while we're at it, I told the dealer that I don't know anything about diesels and if there is anything I should know. He said the only thing he could think of is Adblue but I didn't get what that was all about. Also, the HUD has gone missing.
