Ford Focus Generator Fault

I had a similar experience with my old Opel Astra, although it was a petrol engine. Reduced power, warning lights, and difficulty starting all point towards the charging system. The generator, also known as the alternator, recharges your battery while the engine is running. If it's not working correctly, the battery drains. Have you checked the serpentine belt? That's the belt that drives the alternator. If it's loose or damaged, it can cause the alternator to not function properly. Also, what did the garage say about testing the alternator's output?

Thanks! I appreciate the Opel story. I haven't personally checked the serpentine belt. As for the garage testing the output, they mentioned something about it, but I was so stressed I can't quite remember the details. So do you think my car won't start because of the generator?

Okay, it sounds like the garage is on the right track. If they suspect the generator and mentioned testing the output, it's highly likely that's where the problem lies. Given the symptoms you're describing, it really points towards a defective generator. While it could be a simple fix like the serpentine belt, the fact that there's an error code stored suggests a more serious issue within the generator itself. In my case, the garage confirmed that the alternator wasn't charging the battery sufficiently. I'd strongly recommend trusting their diagnosis and getting the generator replaced. The fault will eventually stop the car from running at all. I would suggest you obtain quotes and then proceed with the cheapest.

Thanks for the advice, it's been a great help! The garage got back to me, and as you and they suspected, the generator was indeed faulty. The entire repair, including a new generator, came to 960€. A painful experience, but at least now I know what's up with the car. The warning light is gone and the vehicle starts perfectly. Everything is in order, thanks again!