Code C2100 on the 2022 Subaru Forester indicates a malfunction in the Lane Keep Assist motor system. This feature uses the electric power steering motor to provide gentle steering corrections that help keep the vehicle centered in its lane when EyeSight detects lane departure.
Lane Keep Assist Integration
Subaru's Lane Keep Assist works through the EPS motor - when the EyeSight cameras detect the vehicle drifting toward a lane marking, the system applies small steering corrections via the electric power steering motor. This requires precise control of the EPS motor beyond normal assist functions, so motor or control system issues can trigger this specific code.
Warning Signs
With C2100 present, the Lane Keep Assist warning light activates and a message appears in the multi-information display. The feature becomes unavailable, though basic power steering assist continues normally. Other EyeSight features like adaptive cruise control and pre-collision braking may still function depending on the specific fault.
Diagnostic Direction
This code points to the EPS motor's ability to provide the precise control needed for lane keeping rather than basic steering assist. Check EPS system health first - motor codes, torque sensor issues, or communication faults between EyeSight and EPS can trigger C2100. The EyeSight system must communicate steering commands to the EPS, so network issues can also be responsible.
Repair Path
Address any underlying EPS system faults. If the EPS motor is degraded to the point it can't provide the fine control needed for lane assist, EPS assembly replacement may be necessary. After repairs, calibration of both EPS and EyeSight systems ensures proper integration and lane keeping function.