Avensis temperature readings and check engine light

Sounds like a thermal management problem. Have you noticed if the radiator fan is running constantly, even when the engine is cold? Also, how's your coolant level? A low coolant level could cause those issues.

Good point about the fan! I'll check that tomorrow morning when the engine is cold. Coolant level seems fine, I topped it off a few weeks ago. If the fan is running non-stop, what does that usually indicate?

If the fan's running all the time, it could mean a faulty temperature sensor is telling the system the engine is always overheating. With those symptoms and the check engine light, I'd recommend getting it scanned by a workshop. They can pinpoint the exact problem and save you from chasing ghosts. Could be something simple, but better safe than sorry with engine cooling!

Thanks, that's solid advice. I checked the fan, and it seemed normal, so I took it to a local shop. Turns out it was just a fuse related to the cooling grille being stuck open, costing me 52€ to get it sorted. Appreciate the help!