In the past I’ve successfully added (programmed) new keys using 2 existing working keys using the “self add” method of inserting/turning/removing etc.

My most recent attempt at adding a new key has been unsuccessful.

questions:

is there a maximum number of keys that can be programmed?

if max is already programmed and you attempt to add a new key (by user add method) what would happen? (Would it bump an older key out OR would it simply not add the new key you’re trying to add?)

any suggestions on what else I should try?

 

Seems that 8 keys are the limit of programmed to PATS system. As I use Ford's IDS system to diagnose ALL my pre 2018 Ford models, I just erase all keys and reprogram clients keys so they can add more at their convenience. I'm sure there is a manual way to find out how many are programmed to ECM, but I never practiced that basic.

Good luck and im sure a more knowledgeable veteran will have a better answer.

 

You'd need to use a capable scan tool or comparable (Windows-based Forscan w/extended license and an OBD interface) to dig deeper into the PATS system.

It is correct that the max number of keys is 8 for the 04-08 F150s. The scan tool/software can read the number of keys programmed. There isn't any other way to determine exactly how many keys are already programmed into the PCM's memory. If the maximum has been reached, it's necessary to erase all and reprogram current keys. Two unique and non-defective keys are necessary to do this, clones do not count. Do not erase all keys without having the needed keys in hand or you'll have a 4-wheeled brick until you get it right.