Some 2017-2021 Ford GT vehicles may exhibit a runs rough or hard start with or without an illuminated MIL with DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306 and/or P0316. Prior to performing any diagnostics, determine if the vehicle operating conditions may have resulted in multiple cold engine start-ups without allowing the engine to reach normal operating temperature and being driven. If that operating condition is determined, inspect the spark plugs per Workshop Manual (WSM), Section 303-00 and repair as directed. If no concern with spark plugs are found, proceed with normal diagnostics per the Powertrain Controls/Emission Diagnosis (PC/ED) Manual. Upon returning the vehicle, refer the customer to the owners guide regarding proper driving cycles.
