Some 2022-2023 Explorer vehicles with 2.3L engine built on or before 20-Jul-2023 may exhibit an intermittent malfunction indicator light (MIL) with diagnostic trouble code (DTC) P1026 and/or P1299 present in the powertrain control module (PCM) and an engine over-temperature message displayed on the instrument panel cluster (IPC) after a cold engine start. The vehicle will also exhibit reduced performance when it enters fail safe cooling open loop mode. If the engine is not overheating, clear the DTCs to reset the fail safe cooling open loop mode. Start and idle the engine while viewing coolant flow at the top inner (engine side) degas bottle hose port through the semitransparent top. If there is no coolant flow, replace the L1MZ-8A365-AAD engine-to-degas bottle hose. If if there is any coolant flow, return to Workshop Manual (WSM), Section 303-03A diagnostics.
