The pass seat heater module gets its signal from the pass door control module, so I would begin by looking at the connectors for the door module first. I would be surprised if this problem had anything to do with the seat module or elements. I would check the grounds first in the door, and that the components are securely fastened to the door structure. The system uses a data link system so a lot of it is not user serviceable. That does not mean diagnosis is easier. Just more expensive........LOL.