How do I fix the transmission of my Ford S-Max?

I have been experiencing issues with my Ford S-Max's transmission, where it gets stuck in a specific gear and won't shift. What could be causing this and how can I fix it?

It sounds like your transmission fluid may have become contaminated or depleted. Try checking the fluid level and condition, and if necessary, bring it to a mechanic for a flush and refill.

Another possible reason could be faulty solenoids or sensors within the transmission. I recommend taking your car to a reputable mechanic for a diagnostic test to identify the exact issue.

It could also be an issue with your clutch or clutch assembly. If you notice any shuddering or slipping while driving, it's best to get it checked out by a professional.