make sure battery is fully charged before trying the procedure posted, a low battery is what caused the system to get locked in the first place. try re-programming the key again then followed posted unlocking procedure. the 708 should do it, procedures are all over the forum just do a search. if there is any other trouble codes besides system locked, post it here. if none of that works we need to talk to your kid I may have a job for him/her locking up vehicles.