Check for a Loose Connector on the Subaru
This bulletin applies to 2019 Subaru Forester vehicles. The DMS (driver monitoring system) may be inoperative.
DTC U0156 for lost communication may be stored in multiple modules. In addition, the seat memory feature may be inoperative. The cause may be a loose harness connector located behind the exterior trim cover of the driver’s door mirror assembly. The upper and lower covers may be carefully removed using a plastic trim tool . With the covers removed, access to this connector is much easier by removing the turn signal lamp from the mirror housing. After re-seating the connector and confirming that it is locked in place, all systems should return to normal. When removing the mirror overs, remove the lower cover first, then the upper. During re-installation, install the top first, then the lower.