SpaceTourer Engine Control Malfunction

That sounds like a headache! I had a similar issue with my 2016 Opel Insignia. The symptoms were identical. Did you check the voltage? It could be a faulty connection preventing enough juice from getting through, like a clogged artery to the heart.

Voltage seems okay. Could the cable connections really be the sole cause?

In my case, yes, it was just that. But it presented the same as a major fault! I'd still recommend a workshop visit for a proper diagnostic check. They have the tools to pinpoint the exact problem.

Thank you for the advice. It turned out to be corroded battery cable connections, as suspected. Repair cost 155€.