Some 2020-2022 Explorer/Aviator vehicles may exhibit automatic transmission fluid (ATF) contamination in the engine cooling system due to the transmission cooler. If the cooling system becomes contaminated with ATF, the system must be flushed clear of the contamination after the source of the contamination has been repaired. It is generally not necessary to replace the following components due to ATF contamination in the cooling system: radiator, heater core, de-gas bottle, water pump, auxiliary water pump, coolant control valves, temperature sensors, thermostat, turbocharger, heat exchangers, tubes, gaskets/O-rings/seals (unless removed), or rubber coolant hoses (unless swollen).