You need to establish, if the engine is getting that hot or the reading is wrong, a stuck thermostat could make it that hot, but the fans should still come on before then.
Most likely on yours they are ecu controlled, and don't use a seperate switch for the fans.
On balance it is most likely a duff sender, bear in mind the gauge one and the ecu are two seperates senders(so do correct one).
tabetha