Radiator fan staying on

[aidan b]

Hello all. I'm here looking to see if I can get some help on a 2013 avensis with the 1adftv engine. The radiator fans come after going for a drive and will stay on when idle for about 15 minutes. Looking at the diagnostic data stream I am getting coolant temp at 100°C but the dash guage is at normal temp. I have replaced the coolant temp sensor on the side of the engine and swapped out the fans for a known good set and still the fans stay on. Is there a resistor that controls the fans? I also replaced the fan relays

[Guest]

Mine stays on longer than any other car I've owned as well, it's a 2018 BMW engine diesel Avensis T27.  I think it seems to be normal for these cars. Walked past a few older mid 2000s Avensis in towns with the fan on too, not sure the cause. 

[aidan b]

S 1500 I don't think this is the case. We have 2 of them here running as taxis and the issue has never been there. It has only come in to it in the last month. 

[APS]

Your fans clearly work. No need to replace them. 

Have you measured the temp sensor you replaced? I don't know the values but presumably it is a resistive sensor where resistance varies with the temperature. Check that the two sensors, new and old, read roughly the same.

Since the fans are not on when cold (?) that would indicate that it does read the temperature but incorrectly. This could either be the sensor itself (which you have eliminated) or possibly a poor earth connection that increases resistance.

Someone else might know if that engine has more than one temp sensors that can trigger the fans.