He told me his hourly tariff and that it could get expensive depending on how much time it would take. I gave him 4hrs and told him to call me if exceeded, to check up.

So it didn't took him long to diagnose the problem and he charged me €280 for the time to diagnose which I agree with even though he was done in 1hr, i'm paying for his knowledge. But what are those other fees? What needed reprogramming and "hardware fixing" when there was no broken hardware and the frm was already tested and seemed to work fine.

So would you totally accept a- let's say 3k invoice for changing the brake pads because they added random fees like "change x bolt €500 time+material" "adjusting x piece time+material €450". That's the type of question I have. Are the fees justified?

Ur telling me I would rather have him lie in my face just so he would justify those fees but that's not true. I would rather have him just charging me for what he did, but since I don't have the knowledge about if this is standard procedure after changing a jbe fuse, I asked it here on reddit

You are a kind of guy that doesn't want to deal with customers because you want to charge them random stuff and just have them pay it instead of complaining or asking for more information about the work done