AMG GT cooling system and communication problems

That sounds rough! I have an AMG GT too. Your symptoms sound familiar to a problem I had. It ended up being a bad data link somewhere in the system causing the control unit to freak out. The car's computers weren't talking properly. I would check your wiring harness and connectors related to the engine control module. It could be a loose connection or corroded pin. Did your mechanic mention specific error codes?

Thanks for the quick reply! A data link issue sounds like it could be it. He didn't go into much detail about the error codes, just mentioned the 'control unit communication error'. I'm not super techy, so could you explain a bit more about what a 'data link' actually is? And how would I go about checking the wiring harness and connectors? Is that something I can do myself, or am I better off leaving it to a professional?

A 'data link' is basically the pathway that allows all the different computers in your car to communicate. Think of it like the internet for your car parts. If there's a break in the connection, the information can't flow correctly, and that can cause all sorts of weird issues, like your overheating and check engine light. As for checking the wiring, I'd honestly suggest having a qualified technician take a look. You could visually inspect the connectors for obvious damage or corrosion, but without the right tools and knowledge, you could potentially make things worse. Especially with a car like the AMG GT, it's best to be cautious. If your mechanic already suspects a wiring issue, it's probably worth letting them diagnose it properly. They'll have the diagnostic tools to pinpoint the exact location of the communication fault.

You were spot on! I took it back to the shop, and they confirmed it was a wiring issue – a corroded connector causing the communication fault. They replaced the connector, and everything's running smoothly now. No more overheating, the check engine light is gone, and no more coolant leaks! Thanks a bunch for your help; I really appreciate the insight!