C1B00: How to Diagnose & Fix — Steering Angle Sensor Fault

NHTSA complaints include intermittent or sudden loss of power steering assist with warning messages, making the van difficult to steer at low speeds. Reports often describe the issue occurring after a restart, during parking maneuvers, or intermittently with electrical/communication faults. The Transit’s EPAS system can set steering-related DTCs and may require module diagnosis or replacement depending on root cause.

The 2012 Mk3 Focus was the first Focus with a fully electric rack-mounted power steering assist (EPAS). The torque/position sensor and motor assembly inside the rack, and the power steering control module (PSCM) integrated with it, fail intermittently - often heat-soaked on long drives or hot days. The dash shows "Power Steering Assist Fault - Service Now", the wheel goes heavy with no warning, and steering no longer self-centers. Failures are frequently intermittent at first (assist returns after a key cycle) and then become permanent. Because the assist motor is integral to the rack, Ford's repair is a complete steering gear replacement. Unlike the Fusion/Taurus/Flex family, which got NHTSA recall 15V340 for the same motor-sensor defect, the Focus was never recalled despite hundreds of NHTSA complaints, and was instead the subject of a class-action suit covering 2012-2014 Focus and Focus Electric.

Sentras equipped with Nissan's Forward Emergency Braking / Automatic Emergency Braking apply the brakes hard for non-existent obstacles ('phantom braking'). The Bosch radar module behind the front grille (sensor assembly p/n 28438-5UD0A) produces false positives, frequently triggered by overpasses, bridges, railroad tracks, parking-garage walls, and metal grates. Nissan disclosed 1,233 related consumer complaints to NHTSA for the Rogue/Rogue Sport/Sentra, including dozens of minor collisions and injury allegations, and the defect is the subject of class-action litigation.

The 12th-gen F-150 uses a belt/column electric power-assist steering (EPAS) system that replaced the old hydraulic pump. Owners report the dash lighting up with a 'Power Steering Assist Fault — Service Now' or wrench warning, after which the assist cuts out and the wheel becomes very heavy, often at low speed in parking lots or during a turn. The failure is usually an intermittent electrical connection or a failed torque/steering-angle sensor or the EPAS motor buried in the rack, sometimes triggered by low battery voltage or a software calibration fault. While the F-150 was not part of Ford's large 2011-2013 sedan EPAS recall (423k Flex/Taurus/MKS), the truck shares the failure mode and it is heavily reported on owner forums.

Multiple Bronco owners reported sudden loss of power steering assist, often accompanied by warning messages and very heavy manual steering effort at low speeds. The issue has been tied to failures in the electric power steering system and steering gear/rack assembly, and Ford issued a safety recall for certain vehicles because an internal steering gear component could fail and cause loss of steering control. Owner complaints and forum reports describe intermittent assist loss first, then complete failure requiring rack replacement.