An F91 code could indicate an abnormality somewhere in the refrigeration cycle, the closed loop of refrigerant gas that the whole cooling and heating process depends on. When pressures or flow through this cycle fall outside expected parameters, the system raises the fault rather than continuing to run inefficiently or unsafely.
This is most often related to the refrigerant charge itself, but it can also stem from a blockage restricting flow through the circuit, such as a restricted valve or filter, or a fault with the three-way valve.
Send us the code and a photo of the display, and a Ford & Doonan technician will get back to you. Please don't reset the unit before you take the photo.
(08) 9331 8800