Renault Master starting issue

Sounds frustrating. Have you checked your battery cable connections? A loose or corroded connection can cause electrical issues, especially with modern vehicles relying on electronic control units. Is the engine turning over at all, or is it completely dead?

Good point about the battery cables! I'll check them. What does 'corroded' look like? Also, the engine isn't trying to turn over. It's dead, like there's no power to the starter motor. Could a bad connection stop it from cranking?

Check those cables. Corrosion can look like a white or greenish build-up around the terminals. If it's completely dead, and the battery is charged, a bad connection could stop it cranking. If you're not comfortable, take it to a workshop for engine diagnostics before making things worse.

You were right about the battery cables! I cleaned and tightened them, and it started. The negative terminal was loose. Cost me 155€ at the shop. Thanks for the help! I feared an engine software or fuel injection pump issue!