Kubistar engine control malfunction

Oh, that sounds rough. Electrical gremlins can be a real pain! When you say cable connections, have you checked for corrosion? Even a little bit can cause a voltage drop and prevent the starter from engaging. Also, are the terminals tight? Give them a wiggle and see if anything moves. Could also be a dodgy earth strap somewhere. Just a thought!

Thank you for the suggestions. Regarding the earth strap, could you specify where I should check for this on the Kubistar?

Okay, so on the Kubistar, without seeing it, I'd say check from the battery to the chassis, and from the engine block to the chassis. They're usually pretty obvious braided cables. But honestly, if you're not 100% confident, and it's still not starting, maybe get it to a workshop. Modern engine management systems are complex, and you don't want to fry anything! Could be deeper than just the battery cables.

I appreciate the advice. You were correct; the cable connections were indeed the problem. After cleaning the terminals and tightening everything, the engine started. The repair cost was 155€. Thank you again.