Chysler alarm system by pass

Chysler Sebring Conv V6 auto trans, will not start, my mechanic tells me the alarm system has me locked out and he can not by pass it even with the alarm button on key change, he advised me to take it to the dealer, any iteas out there.

How did he make this determination? If he’s correct, it may be that only the dealer can reset it. You didn’t mention what year, which would affect what type of system is installed.