S90 AdBlue Empty Error No Start

Whoa, that sounds familiar! I had a similar issue with my 2017 Peugeot 308 diesel. I kept getting the DEF fluid warning despite topping it off. Could be a faulty sensor, but the 'no start' condition points to something more serious. How was the performance before this? Any weird smells or noises?

Hmm, a faulty sensor... Before this, it ran perfectly, smooth as butter. No weird smells or noises. Could the sensor be throwing a false alarm, or is it struggling to inject the AdBlue into the SCR catalyst?

In my case, the AdBlue pump had failed. It was like the pump was trying to supply AdBlue to the SCR catalyst, but the tank was always empty! The sensor was just reporting what it saw – no AdBlue being used. Since yours is preventing a start, it's likely a similar issue, or a blockage somewhere. I'd advise going to a workshop.

Thanks for the insight! A workshop visit is inevitable. Hopefully, it's just the pump. I'll let you know what they find. I appreciate the help!