Subaru Loses Communication

June 1, 2020

This bulletin applies to 2019 Subaru Forester vehicles. A small number of field reports have been received with a concern involving the DMS (driver monitoring 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 fully locked in place, all systems returned to normal operation.