Skoda Octavia Diesel Overheating Issue

Overheating on a 2002 Octavia diesel is concerning. The check engine light and coolant spill definitely point towards a serious issue. A control unit communication error, especially with those symptoms, often does involve wiring or connector problems, as you suspect. Have you checked the coolant temperature sensor wiring? Also, are there any other modules throwing communication fault codes on the CAN bus? It is difficult to diagnose without detailed car diagnostics. Also, when was the last time you inspected or replaced the thermostat?

Thanks for the quick reply! I haven't specifically checked the coolant temperature sensor wiring, but I did visually inspect the main wiring harness for any obvious damage. As for the CAN bus, is there an easy way to check which other modules might be throwing codes without having to take it to a shop right away? Thermostat was replaced 3 years ago.

Given the symptoms and the age of the vehicle, a connectivity issue within the CAN bus system is plausible. While a thorough car diagnostics scan is ideal, without proper equipment, pinpointing the exact module at fault can be difficult. Based on your description, I would strongly advise against continued operation of the vehicle in its current state. The risk of further engine damage is significant. It's advisable to have a qualified technician perform a comprehensive car diagnostics and address the wiring issue. It sounds like a wiring issue is highly possible, but it's best to leave it to experts.

Just wanted to let you know, it turned out to be exactly as you suspected, a wiring issue! The car diagnostics pointed to a connectivity issue with the CAN bus. The total repair cost was 95€, a defective cable was the culprit. Thanks for your insights!