In the service manual for my 2005 TL it says once the belt replace to do a Crankshaft Position (CKP) Pattern Clear/CKP pattern learn procedure. For one I have no idea what this is, even when reading what needs to be done and second is this really necessary? I don't understand what changes when a belt is replace.

thanks

 

you dont need to. its just if u unplug it it will sometimes flip a code with the pcm.