DTC U0554: Invalid Data Received From Accessory Protocol Interface Module: Action
WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
CHECK for additional RCM and APIM DTCs. For RCM DTCs, RETURN to the beginning of this chart. For APIM DTCs, REFER to the APIM DTC Chart in the appropriate Information and Entertainment System - General Information article