DRV8829: DRV8829 with linear actuator

Part Number:DRV8829

Hello Good day,

I have a DRV8829 setup like the typical application page in the datasheet, i am trying to drive a 12V, 0.5A typical linear actuator (it becomes open when it reaches one end). 

I notice that the fault pin goes LOW when the linear actuator reaches one end indicating that the protection was activated. It can't be over-temperature because nothing goes hot,

it can't be under voltage because voltage supplied to VM is constant (12V), so it must be overcurrent, but i dont understand why since my linear actuator only reaches up to 0.5 A.