Why does my fan turn on after the engine has been turned off?

On most modern vehicles the engine cooling fans are electric. These fans are thermostatically controlled and will continue to run even after the vehicle is turned off and until the engine cools down. If you feel the fan is running an excessively long time after you turn off the vehicle, I would recommend you have it looked at by the dealer.
Good luck.

depending on the engine temperature the fan is supposed to remain on after you turn the engine off, until the engine reaches a preset cooler temperature. when it reaches cooler temperature usually within 5 minutes or so it should cut off... if you cut it off and it is running 30 minutes later.. then there is a problem with the fan relay or temperature sending unit.

if engine at long stand still,the engine temperature will rise about 190 degrees the cooling fan suppose to automaticaly turn on when coolant temperature sensor get hot it cause its resistance decrease causing pcm to send power to coolant fan relays and cooling fans, when you turn on AC the cooling fans suppose to turn on to cool down AC CONDENSOR, IF NOT AC WONT WORK COOLING FAN COOLS DOWN REFRIGERANT SO IT CAN RECYCLE THROUGH THE SYSTEM AGAIN.your cooling is suppose to turn on when engine at a sit still if vechicle not moving as coolant temperature rises at a set point the cooling fans will turn on cool down engine.cooling fans dont turn on when you first cold stsrt vechicle unless you have AC SWITCH ON.if cooling fans dont turn on when vechicle at a long stand still or moving along slow traffic.if coolant temperature sensor been replaced and fuses and relays okay have dealership check see if pcm driver circuit working faulty pcm will cause cooling fans not to turn on.

Would turn the key on no need to start it and unplug the ect engine coolant temp sensor. If fans come on then suspect a faulty etc which may not turn on the engine light. Which engine is in the vehicle so I can help locate the ect which is usually by the thermostat housing.

You may have one conventional belt-driven fan with a thermal clutch and the other electric or, both could be electric on your car.
The cooling fan that operates during non-AC operation (just a running engine) if electric, will be controlled by a thermal switch in the lower radiator tank and may not turn on at all unless the engine is warmed up. The belt-driven fan should be turning at some speed all the time if the engine is running and at much higher speed with a hot engine.
The fan that cools mostly when the AC is operating won't run under normal operation but may turn on in hot weather (or when the engine is under heavier loads) even without the AC operating.
Checking them would require having a warmed-up engine and the AC turned on. Both fans regardless of type should be turning then.

If you are having a problem with overheating then I would be worried about it I have worked on these types vehicles alot and most the time when you turn on the vehicle the fans dont normally kick in until the teperature rises then they will kick in just long enough to cool the engine down then they will turn off then the cycle begains again over and over so you see it is always that when you turn on the vehicle that the fans should turn on. Yes the ets or ects does send the signal to have the fans turned on but if the vehicle does not need to be cooled then they will not turn on. Try idling the vehicle long enough to heat the engine up to a temperature hot enough to turn the fans on you will see they come on then off DO NOT OVER HEAT THE ENGINE THOUGH.

automatically. even if the motor is off.

will try to help. the fan you replaced, was it the air conditioner fan? if so. then you need to check your primary fan. the one that does come on when the engine reaches operating temperature. make sure by starting engine, let the motor run and the temperature guage reaches the normal operating temperature.if the main engine cooling fan does'nt come on, then you'll need to check the fuse box under the hood. relays are black square plug in's they are marked and will[fan relays] tick when you turn the key on] if main engine fan does not come on when engine overheats, #1 fuse blown #2 relay bad #3 main cooling engine fan bad. note; the air conditioning fan will come on with engine running,when air conditioniing is turned on. when the a/c is turned off, the a/c fan will not be turning. hope this helps and as always, thank you for choosing fixya.com

The cooling fans won't run until either the engine coolant temperature reaches about 218 degrees or the air conditioner/defroster are on. Once the engine reaches appx 218 degrees the fan will come on and run until the coolant temperature drops a few degrees and will then turn back off. If either the a/c or defrost are turned on then the cooling fan will begin to run to remove the heat from the a/c system and should stay on until either is turned off. If the engine is overheating in slow or stop and go traffic then the fan may not be working at all due to a bad fan motor or blown fuse.

Likely the fan(s) not turning on when engine gets hot. Is the check engine light on? Read the code(s) and repair as needed. Check (when cold) the fan(s) for free turning--if seem bound or hard to turn, replace the ailing fan. Check the radiator and reservoir fluid level. Watch the fans as the engine heats up. Feel the radiator area where the upper engine hose connects. It will suddenly turn hot when the thermostat opens. The fan assembly should activate somewhat after. Hopefully, the engine code recognized a defective temp sensor and was replaced.