Sprinter AdBlue System Problem

That sounds like a pain. It's a common fault. Does the error code specifically point to the AdBlue pump or a sensor issue within the DEF fluid tank? Have you checked the pump relay and fuse? Sometimes it's a simple fix like that. If the pump's faulty, it can't draw the AdBlue, and the injection system will cause an issue. These emission control systems are overly sensitive. There could also be a blockage in the line, preventing the DEF fluid from getting where it needs to go. Have you checked for leaks around the tank and lines?

Thanks for the quick response. The error code is vague, just says 'AdBlue system malfunction'. I haven't checked the relay or fuse yet. Where are they located on this model? I haven't spotted any leaks, but I'll take another look in the morning.

The fuse box is usually under the driver's seat or in the engine bay near the battery; the relay should be close by. Check the handbook; there are diagrams inside. If they're okay, it sounds like the pump itself is failing, or there's a blockage inside the tank stopping it from picking up the DEF fluid. Honestly, I'd advise taking it to a garage. It could be a sensor fault, and you don't want to mess with the injection system. They can properly diagnose it and replace the faulty part. Otherwise, you're just guessing.

The fuse and relay are fine. I took it to the workshop. You were right; the AdBlue pump in the tank had failed. A new pump was fitted, and all is well. It cost me about 250€, but at least it's fixed. Thanks for the help.