Car won't start after getting the PCM refurbished

If the battery wasn't disconnected before removing or re-installing the PCM, the PATS (Passive Anti-Theft System) might've kicked in. To reset it first try the reset procedure. If that doesn't help, perform a hard battery reset. Anti-Theft Reset:

 

Turn the key on, disconnect the battery, and wait one minute. With the key still on, reconnect the battery and then start the vehicle.

 

Hard Battery Reset: