A P0554 code on your 2020 Subaru Forester indicates intermittent signal from the power steering pressure sensor—the signal is present sometimes but drops out or fluctuates unexpectedly.
Intermittent Signal Characteristics
P0554 indicates the sensor works but the signal is unreliable. It may work fine sometimes then fail momentarily, creating gaps in the data the ECM needs for idle compensation.
Forester Steering System
The 2020 Subaru Forester uses electric power steering, which doesn't have a traditional hydraulic pressure sensor. Verify this code's applicability to your specific vehicle using Subaru Select Monitor.
Understanding Electric Power Steering
Subaru's EPS system uses motor current sensing to determine steering effort, not a pressure sensor. If P0554 appears, it may relate to EPS motor or torque sensor issues rather than a hydraulic pressure sensor.
Diagnostic Approach
Use Subaru SSM to verify the actual fault code and system affected. If the code relates to EPS components, monitor torque sensor and motor data during operation. Look for intermittent connection issues in the EPS system. Check for loose connectors or damaged wiring.