Hello and welcome to JustAnswer!
P1491 is for the a/c condensor fan relay's control circuit. This isn't an uncommon code to set. Find the condensor fan fuse in the fuse box, I believe it's fuse 39 (but could be wrong). You should find that the fuse has blown. If it has, you'll need to have the fan assembly replaced. All parts of the fan have been revised a few times along the way. The shroud and blade have been changed to stop water accumulation at the bottom, and the motor itself has gone through changes to make it last longer.
do you happen to know approximately what the parts would cost?
No, this isn't related to the engine cooling system at all. This is an electrical problem with the a/c condensor fan's relay.