Seat Toledo turn signal issue

Did you check the flasher relay? I had something similar happen on my old car. Worth a look before you start swapping bulbs. Does the error say which signal is acting up?

The flasher relay looks okay. The error is pretty vague, just says 'turn signal problem'. Any other thoughts before I start taking things apart?

Okay. With a vague error and your checks, a bad cable or plug connection is likely. Cleaning the contacts might help, but honestly, those symptoms suggest a workshop visit.

Right. It was a bad plug connection, just like you thought. Cost me 95€, but it's sorted. Thanks for the advice.