Master Engine Overheating

Good day. It sounds like you're experiencing a rather complex issue with your Renault Master. The overheating, combined with coolant spillage and the check engine light, does indeed point to a potential problem with the engine's control system. The control unit, sometimes referred to as the engine control module (ECM) or engine control unit (ECU), is responsible for monitoring and regulating various engine functions. If it's throwing errors, it could stem from a few things. I would recommend checking for software glitches, wiring issues, or connectivity issues.

Cheers for the quick response. When you say 'connectivity issues', could you elaborate a bit? What kind of connections are we talking about specifically? And what's the easiest way to check for a software glitch without specialist tools?

Of course. By 'connectivity issues,' I am referring to the physical connections – the plugs and wiring harnesses – that link the control unit to the various sensors and actuators throughout the engine. A loose, corroded, or damaged connector can interrupt the signals being sent and received. As for software glitches, unfortunately, without specialized diagnostic equipment, it's extremely difficult to definitively rule out a software problem. Given the symptoms and your initial thoughts, and considering the costs, I would advise that you consult with a qualified mechanic who can perform a proper diagnostic scan and inspect the wiring. It might save you a lot of time and prevent further damage.

Thanks for the advice. I took it to the shop and you were bang on the money. Turns out it was a defective plug connection to a control unit. Cost me 95€ to get it sorted. Appreciate the help.