Seat Mii Heavy Steering Issue

Sounds like a faulty steering angle sensor. Have you checked the electronic stability program (ESP) and traction control system? Those are often linked. Sometimes, a simple reset can fix it, but if it's a sensor issue, replacement might be necessary.

Thanks for the quick response! By 'reset', do you mean disconnecting the battery for a bit? Or is there something more involved? Also, how difficult is the sensor replacement? I've done some basic automotive sensor work before.

By reset, I meant a diagnostic reset using an OBD2 scanner. But given the symptoms, I suspect the coding is indeed off, causing the issues with the electronic stability. Sensor replacement can be tricky; it often requires recalibration and a wheel alignment afterwards. Best to get it checked at a workshop to be sure.

Took the Mii to a workshop, and you were right. It was the steering angle sensor coding. They recoded it, did a wheel alignment, and now it's driving like new. Cost me 195€, which is annoying, but at least it's sorted. Thanks again for the help!