Hi i need help with my 16 mustang , my key fob remote Suddenly not start up the engine from far .. but its lock/unlock doors .. after that the key fob remote sometimes start engin and sometimes not!!

and i check the computer of the car in Dealer.. they said :no thing wrong..

And i buy new key fob remote also.. its same problem !
what can i do ?

 

I was going to suggest replacing the battery in the key/fob as the first simple trouble-shooting step, but if you already replaced the entire key/fob, then that is not it

what did the dealer say about the key problem?

 

They dont know .. They kept the car and trying to find solution. :/

 

It might be a reciever problem with the car. That would be my guess