hi all, I have a 52 plare freelander t4. ive recently started to have trailer lessons with it, and noticed when we picked up speed the hill decent light came on the dashboard with the exclamation mark? The horse trailer was empty, but unsure why it came on. when back at the yard I turned the engine off and restarted it and the light hasnt appeared since. is this the norm or could there be a problem. didnt notice a diffrence in towing when the light came on? thanks xx