Volvo s80 cooling fan problem

Ro74

I have a 2010 Volvo S80 1.6 drive diesel and the cooling fan seems to come on even when engine cold , I have topped up air conditioning and changed fan switch , thinking now it might be a fan module itself which is very expensive as whole fan and module is one unit €420
Anyone else come across this fault, it's only annoying as the fuel consumption is ridiculous while fan runs
Thank you

Atlantic Dawn

Have you checked coolant level? Does it happen if AC is turned off?

Ro74

Atlantic Dawn wrote: »

Have you checked coolant level? Does it happen if AC is turned off?

Yes of coarse I'm a mechanic myself , a/c off and it still comes on , that's why it's annoying me so much
Thank you

Autochange

is the fan funning at low or high speed?

Ro74

Autochange wrote: »

is the fan funning at low or high speed?

It's running high, didn't come on all day yesterday and I drive 80 km , this morning when it was -2 Celsius out side the fan came on after 5 mins and the car temperature was only 62 degrees

The Red Ace

looking at a Volvo wiring diagram it looks like the fan module is fed from the (ecm) engine control management module, I would think from looking at the diagram it is more likely the ecm, with a meter you should be able to establish if the fan module is constantly powered or otherwise, if not to me it would suggest the ecm, if you cant identify the problem could you fit a regular rad stat and feed the fan motor via the extra stat

Ro74

The Red Ace wrote: »

looking at a Volvo wiring diagram it looks like the fan module is fed from the (ecm) engine control management module, I would think from looking at the diagram it is more likely the ecm, with a meter you should be able to establish if the fan module is constantly powered or otherwise, if not to me it would suggest the ecm, if you cant identify the problem could you fit a regular rad stat and feed the fan motor via the extra stat

Yes that's correct , tried rewiring but as soon as I started tampering the engine management light comes on and car goes into low power mode , I asked Volvo to reprogram the Ecu/ecm and they said it wasn't necessary, don't think they know what they are even doing down there

Ro74

Ro74 wrote: »

Yes that's correct , tried rewiring but as soon as I started tampering the engine management light comes on and car goes into low power mode , I asked Volvo to reprogram the Ecu/ecm and they said it wasn't necessary, don't think they know what they are even doing down there[/quotes
It does have two constant powers to it I believe , I will check for sure tomorrow

Blahfool

Had some fan craziness with an s40. Very similar symptoms. Does the engine run cool? Change of a stuck thermostat cured mine. Not particularly logical but worked. At less than a tenner thought I'd mention it.

Ro74

Blahfool wrote: »

Had some fan craziness with an s40. Very similar symptoms. Does the engine run cool? Change of a stuck thermostat cured mine. Not particularly logical but worked. At less than a tenner thought I'd mention it.

It doesn't run cool but they do heat up very fast, actually heard that before that a stuck thermostat could cause the problem, I will actually pull it out and test it, thanks for your input
Much appreciated