Maybe this will help a little. I attended camp freightliner years ago, and we learned that the coach builder locates the vdc (shipped temporarily strapped to the chassis from Freightliner).
On the Holiday Rambler DP we had, the VDC and Transmission computer were in the upper portion of one of the storage bins...mounted up high in the bin with a plastic cover over it.
It will likely be near the engine.
Have you tried posting your question on the Freightliner Owners group on IRV2? Or try the Owners Group for Fleetwood Products on IRV2.
Good luck with your search.
Fred
Fred & Vicki
St. Augustine, Florida