Thread: Electric fan on from start up

Hi, is it still on with aircon switched off?
1. if no the ambient air temp sensor(behind the front grill) is fubar'd and it sends an above 28*C reading
2. if yes you need to plug in a tester and clear the engine temperature/sensor related fault code(s) logged in the ECM
3. if you observe that the temp gauge reads more than normal it's possible that the coolant temp sensor is fubar'd and must be replaced

be aware that if the aircon is switched on and there are more than 25*C outside the fan will be on too... and if the engine is hot even at lower ambient temps cos the sensor gets some warm from the radiator too

if non of the above helps there is some other possibilities but more complicated... i'll tell you if it's the case

Thanks, good, brief, to the point, I have just found mine doing the same thing.

If I disconnect the air temp sensor will that cause another problem, will disconnecting it just to prove the point be OK?

Cheers

Mike

Hi, you dont have to bother and remove the grill to disconnect the air temp sensor to check it cos the open circuit will keep the fan on anyway... if you suspect it push the TEMP button on the aircon controll and compare the displayed temp with the real one.... if that reading is completely strange that's it. ... also you can run that diagnostic check with the unit's protocoll too(attached), the temp sensors are covered for open/short circuit

Originally Posted by sierrafery

Hi, is it still on with aircon switched off? 1. if no the ambient air temp sensor(behind the front grill) is fubar'd and it sends an above 28*C reading 2. if yes you need to plug in a tester and clear the engine temperature/sensor related fault code(s) logged in the ECM 3. if you observe that the temp gauge reads more than normal it's possible that the coolant temp sensor is fubar'd and must be replaced be aware that if the aircon is switched on and there are more than 25*C outside the fan will be on too... and if the engine is hot even at lower ambient temps cos the sensor gets some warm from the radiator too if non of the above helps there is some other possibilities but more complicated... i'll tell you if it's the case

Hi Sierrafery

Mine is also doing the same thing. How do you check the ambient air temp sensor is ok or not. I dont have a nanocom unfortunately.

The temp gauge is ok so I can say the coolant temp sensor is ok.

Thanks
Gus

Originally Posted by dearot

Hi Sierrafery

Mine is also doing the same thing. How do you check the ambient air temp sensor is ok or not. I dont have a nanocom unfortunately.

The temp gauge is ok so I can say the coolant temp sensor is ok.

Thanks
Gus

hi, you misssed my post above yours

Originally Posted by sierrafery

hi, you misssed my post above yours

😃



I just tried as your attached documents and show code 21 and 22. It says No Solar heating correction. What does that mean?

if the car was in the garage or there's no sun outside you'll get this fault code...it's to be worried about it only if you get this fault code when the sun shines to that sensor(that button kind of thing in the middle of the dash near the bottom of the windscreen)

also the diagnostic covers only open/short circuit of the temp sensors not erratic readings

Originally Posted by Joseph

Good morning. Up to my second post now. Working through a 2001 td5 auto I have had for a few weeks now. I have noticed that the electric cooling fan in front of they radiator comes on from when you immediately start the car. I have had a dig around and from what I can tell it's not supposed to. Any suggestions appreciated.

Cheers
Joe

Its also worth checking, because its not a new vehicle, that a previous owner hasn't "hot wired " the fan to run all the time because of a previous issue they may have had.


Just a thought.