I have a problem with my car that I cannot fix...
As soon as I turn the inition, even before starting the car, the fan starts running and keeps staying on until I turn off my car and the turbo timer countdown finished and turns the engine off.

I replaced the fan motor, didn't work.
I replaced the fan switch, didn't work.
It sometimes goes to normal and won't turn on but %80 of the time, I get this problem

What might the problem be??

 

same problem here, but idc bc it keeps my car cool

 

I think this is a malfunction of the ECU or the fan control module, I don't know which. The ECU gets info from the speed sensor, engine coolant sensor and A/C system to obtain the needed fan rpm. It then operates the fan control module. The fan control module contains a temperature sensor so it must have some control too. I guess I would try a new fan control module first, it is the cheaper part.

 

I did change the fan control module but didn't work
We looked at the calibration on the ecu since the the previous owner got the tune done and we thought the problem might be there, everything seems to be normal there too

 

I was experiencing this problem as well when I had my O2 dump, as soon as I got rid of it, fan never stayed on, but does when cooling like usual. Your problem sounds like a thermostat piece going bad or the switch for it. GL

 

It does sound like the thermostat, a family member of mine had the exact same issue in her mitsubishi. Don't let it go on for too long otherwise you might burn out something else with the fan running all of the time (also happened to her).

 

What's the temp gauge on the dash doing? When you unplug the coolant sensor close to the thermostat, two things happen, the temp gauge shoots up, and the fans stay on.

This sensoris really cheap, I would change it and see if that is the problem. Also, make sure you have a grounding kit on there, even a home made one. That sensor gets a bad signal from the stock ground sometimes.

 

Just throwing it out there. But if have the AC button engaged it will always run the fan for the condenser.

 

No it will not. The fans do not run continuously, even with the AC on.

 

UPDATE!!

Like I said before, the fan switch and the fan module are fine
When I remove the relay from the fusebox, the fans stop
So after I removed the relay, I checked the female side (the part that is on the fusebox where the relay is plugged into), and it is getting a consistent ground
How can a grounding kit fix this?? As far as I know, the grounding kit connects to the + and - on the battery and the other grounds connect to the engine block, fuel rail and intake manifold...

 

I will try the thermostat...


The temp gauge is normal just below the middle

 

Could be a stuck fan relay?

 

Sure it does. It's the AC compressor that cycles not the fans. As long as the computer sees input that AC is on it runs fans continuously. Turn key on but don't start. No fans. Now turn AC on car not running. Fans kick on and stay on.

If you have a dvom or test light this would be easier. At the relay test and see if it recieving a signal from ecu. If its not then the relay is stuck closed completing the circuit.

Thermostat doesn't control fans. Only controls coolant flow. Temp sensor controls fans. You should have a 5V reference voltage coming into that sensor and a good ground on the other. You can also ohm out the sensor.

 

UPDATE!!!

I have changed the thermostat, fan switch, fan motor and the relay but still have the problem
When I bought the car, it already had a tune on the stock ECU. We thought that might be the problem so we changed the ECU with a Motec M800 and turned the fan off, it is still working???

 

i had this problem on a evo 8, it turned out to be water getting into the passenger footwell there was 2 wiring plugs with corroded pins.