Mini Cabrio Overheating and Coolant Leak

Overheating and coolant loss on your Mini Cabrio sounds concerning. When the check engine light came on, did you notice any changes in how the car was running, like rough idling or loss of power? Is the coolant spill constant, or does it only happen after driving?

Given the coolant spill only happens after driving and the engine overheating, the excessive pressure in the cooling system points towards a problem linked to the engine's temperature regulation. A control unit communication fault can definitely cause this. The wiring issue could be anywhere along the harness that connects to the engine control module. Without proper diagnostic tools, locating the fault can be tricky. I recommend taking it to a workshop.

The engine seems to run normally apart from the overheating. The coolant spill is only after driving and seems related to the engine getting hot. Where exactly should I be checking for a wiring issue? Is there a common spot for these control unit communication faults in the diesel Mini?

Just wanted to provide an update. Took the Mini Cabrio to the shop, and you were right. They found a control module connectivity issue and some frayed wires. The communication fault was indeed the root cause. Repair came out to 95€ – thanks for your input.