Check the Subaru's Connection

Note the harness connectors in driver side door mirror.
| Photo Credit: Mitchell 1This bulletin applies to 2007-2019 Subaru Forester vehicles. A “small number” of field reports have been received with a concern involving the DMS system being inoperative.
One of these reports stated a DTC U0156 for lost communication was stored in multiple modules. In addition, the seat memory feature was also found to be inoperative.

After performing extensive electrical diagnostics, the root cause was traced to a loose harness connector located behind the lower exterior trim cover of the driver’s door mirror assembly. After re-seating the connector and making sure it was locked in place, all systems returned to normal function.