p0472 is the code for the torque converter clutch release switch in the valve body of your transmission. it could be numerous things and a transmission shop is definately the way to go. if that switch is failing it would produce the issues you described in your first post.

P1554 is related to your cruise control system. and i would once again reccomend a transmission shop to have a look.

wasnt able to find any info on the third code.