Mercedes B Klasse Diesel check engine light and rough idle

Sounds frustrating I have a similar B Klasse A while back, I had a similar issue with the check engine light coming on and a rough idle Turned out to be a faulty sensor It's like a bad tooth – small problem, big pain Have you checked the sensor's connection Sometimes it's just a loose wire

Thanks for the quick response By 'sensor connection,' do you mean the wiring harness and the plug itself Is there anything specific I should look for, like corrosion or loose pins Also, did your engine stall completely, or was it just a rough idle I'm trying to narrow down the possibilities before taking it to a workshop

Yep, the wiring and plug Give them a wiggle and see if anything changes If you have a multimeter, check for continuity But honestly, given your description, especially the engine stalling, it really does sound like a trip to the workshop is in order They have the diagnostic tools to pinpoint the exact problem, otherwise you will be throwing parts at it In the end, I had it diagnosed and repaired in the workshop

Alright, thanks for the advice I checked the connections, and everything seemed fine I took it to the workshop, and you were right – it was the fuel pressure sensor, with a defective cable connection The repair cost me 95€ Hopefully, this will also resolve the poor fuel economy issue Appreciate your help