Hi, new guy here. For some time now the radiator fan on my 2015 diesel VRS has been coming on before the engine has even reached half way to normal temp and never goes off. Been to 2 different garages who are unable to fix this issue. (According to their diagnostic equipment there are no faults so nothing to fix). I am fairly certain that it is not due to the re-gen, and it is not the air con at fault. I was thinking that maybe the fan sensor is faulty but have no clue where to start looking for this assuming this is the problem. I am also using about 25% more fuel which I put down to the fact that the fan is on. I have had the car from 6k miles, now at 143k so safe to say I know something is not right. Thanks in advance for help.

We need a code scan done.  Please find a local user with either VCDS (genuine) or ODBEleven, do a full code scan and post your output here.

No fault codes present

I'm not an expert when it comes to diesels with dpf but there are a lot of parameters that can be checked even without a fault code to check the dpf management is as expected.

 

It could be fan controller has gone and stuck on. Normally a code would be stored.

 

Need to get a garage who will properly diagnose for a fee. Or get your hands dirty and a full scan tool for parameters. Also on diesels there maybe a secondary app required for dpf control. Someone else will buzz in I'm sure as I don't really do diesel stuff myself 

On 28/12/2024 at 14:52, pringle_monster said:

No fault codes present

What did you scan it with?

Done a scan. History attached. Means nothing to me!😂

I know about the Gearstick switch problem and the Air distribution flap motor problem.

Skoda history.txt

Mm that seems to be at least a back up file having all existing coding in case you need to recode something or so. Good to have.

 

Long file, I didnt read all in hope to find stored faults. Perhaps they are there. Maybe filter the faults and post them in a message.

 

About the original fault description, radiator fan always on, idk if there is a relay to send power to fan? Stuck relay could cause that. Electric diagrams could tell if there is. Otherwise I wud guess some temperature gauge is giving false reading (too high all the time) and therefore asking for the fan to run. Perhaps a temp sensor at radiator outlet. Probably some diagrams would tell how the fan is controlled. The car dont necessary recognize sensor to be faulty if it gives a reading that is in normal measuring range of the sensor.

 

Edit.

With a scan tool and cold car you cud check all temperature sensor readings.

 

Edited 17 January, 20251 yr by RattleWagon

RattleWagon. Just to clarify the fan isn't on at cold but kicks in at about 1/2 way to normal on dash temp gauge. My feeling is that it is some sort of sensor. Did look at some circuit diagrams but they don't tell me the physical locations of all the sensors.