I assume that it's has never worked and that's why you need to sync it. If that's the case maybe someone with the same unit will have found theirs.
There have been reports of the receiver being in the passthru behind a wall. Some have been found near the power panel/converter. Others are behind a screwed in panel. Ours is behind a screwed in panel under the oven.
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!