Communication For Initializing Impossible: Trouble Symptom

WARNING: This page is about a different car, the 2015 Subaru Outback and 2015 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.

Communication is impossible between the power steering control module and Subaru Select Monitor.
After starting the engine, the STEERING warning light does not illuminate but steering effort is heavy.