Hi guys,

My 99 mazda 626 4 cyl with automatic transmission has the following issue:

when driving under 40 miles/hours everything is fine. when you push the car on the freeway to reach the 60 miles/hours the transmissions the car act like you are in neutral, so when push the accelerator it's like in neutral.
So when the speed come down you can drive normally again.
This is like when the car go push the 4th gear it jump to neutral.

Anybody has an ideal what's going on? is it the transmission range sensor(neutral safety switch)? or the transmission by himself need too to replaced?
thanks for your answer...