Renault Master Generator Failure

Sounds familiar! I had similar issues with my old Opel Vectra, though it was a petrol engine. Reduced power, warning lights all over the dash, the whole shebang. Have you checked the voltage drop across the battery terminals when the engine is running? A faulty generator can cause all sorts of electrical gremlins. Also, inspect the serpentine belt for wear and tear; a slipping belt won't drive the alternator properly.

Voltage drop, huh? I'm not really sure how to check that. And the serpentine belt... Where exactly is that located? I'm not much of a mechanic, to be honest. Is it something I can easily check myself, or should I just take it to a shop?

Okay, if you're not comfortable with a multimeter, I wouldn't mess with the voltage check. As for the serpentine belt, it's usually at the front of the engine, driving various pulleys. You'd be looking for cracks, fraying, or excessive slack. Honestly, given all the symptoms, and the fact the error memory points to the generator, I'd say bite the bullet and take it to a workshop. Could be a defective generator like the error says. I ended up needing a new alternator on my Vectra, so prepare for the worst.

Thanks for the advice! I took it to the shop, and you were right – it was the generator. Cost me 960€ to replace, but at least it's running smoothly now. Appreciate the help!