Seat Cordoba Diesel Overheating

Sounds like a CAN bus issue. It's like the car's nervous system, relaying messages between the electronic control units. A problem with the data link can cause weird symptoms. Overheating and warning lights are consistent with a control unit communication error. Does the check engine light stay on, or does it blink? Any other electrical issues?

The check engine light is solid. Nothing obvious comes to mind regarding other electrical issues. If it's a CAN bus thing, can I check it myself, or should I take it to a mechanic to check the control unit?

A solid check engine light still indicates a communication problem. You might visually inspect the cable and plug connections for damage, but CAN bus issues can be tricky. It's like a chain of lights – one faulty bulb can knock out the whole string. You'd need specialized car diagnostics tools to pinpoint the break in the data link and test the control module. Given the overheating, it's best to get it checked by a professional. Driving it could cause more damage.

Just a heads up, the issue is resolved. It was a faulty connection, like I thought. The garage used car diagnostics to find it, cleaned the data link connection, and now it runs. Cost me 95€.