XC60 Reduced Engine Power Warning

The symptoms you describe, specifically reduced engine power coupled with an error code pointing to the engine control unit (ECU), are certainly indicative of a potential ECU malfunction. It's plausible that a defective main relay could be the culprit. The main relay is responsible for providing power to the ECU, and if it's failing, it can cause intermittent or complete loss of power, leading to the errors you're seeing. Have you checked the relay itself for any signs of corrosion or damage? Did you perform any car diagnostics to confirm the issue?

Thanks for the quick reply! I did check the relay visually, and it looks okay, no obvious corrosion. As for car diagnostics, I just used a basic OBD2 reader to pull the error code. Is there something more in-depth I should be doing? I'm not really sure where to go from here. Is it worth trying to replace the relay myself, or am I potentially opening a can of worms?

Given that the visual inspection of the relay didn't reveal any obvious issues, and you're only using a basic OBD2 reader, it would be prudent to seek a professional car diagnostic assessment. While replacing the relay might seem like a straightforward fix, it's essential to confirm that it is indeed the root cause of the problem. Furthermore, the error stored in the error memory regarding the engine control unit could suggest more complex issues within the ECU itself, or perhaps even the vehicle electronics connected to it. Considering the potential for further complications and the sensitive nature of engine performance in a hybrid vehicle, I strongly recommend consulting a qualified workshop for proper car diagnostics.

Thanks a lot for the advice. I took it to a local shop, and you were spot on – it was indeed the main relay causing the ECU issues. They replaced it, and the 'Reduced Engine Power' warning is gone, and the error is cleared. Total cost was around 120€ Appreciate the help!