Cooling fan for engine not working - 13 XC60 T6

[scot850]

A friend of mine has an issue with his car overheating and realized his engine cooling fan is not working. He bought a cheap Amazon fan controller to try it as it is the quickest way to get one. He fitted it and still nothing. Now the fan controller (dual fans) is aP3 issue I know, but is it possible the fuse could have blown? It is an 80A fuse so I thought it was unlikely, but I will check it when he limps it over in a couple of days so I can hitch up Vida to see if anything shows.

Anyone had a similar issue with the fan motors not working and found a fix other than the controller (I do have low expectations the Amazon part is good, but I would expect it to work even for a short time if it was the controller only that failed.

Thanks,

Neil.

[chrism]

You could bypass the controller and feed power directly to the motor just to make sure the motor is good.

[scot850]

That is a great idea. At least we can eliminate the fans as an issue. Thank you!

Neil.

[scot850]

The owner did this. The motors are working fine. He has now tried an Amazon and a Gates fan controller and neither worked.

Strangely, he said that after the engine was running the fan then ran when the car was switched off!?

He is bringing it over today and we will try it on Vida and see if we can make it run,

Neil.

[scot850]

So here is an update, still no luck fixing this issue. Next, off to our local friendly dealer for diagnostic check!

This is a really weird issue that I feel we are missing something with this system. We have identified:

1) Fan will run if power is taken directly to the fans. There is power to the fan controller.
2) Fan will run when engine is switched off for a short time - normal
3) Tried 2 fan controllers, one Amazon special (internally wired in reverse), a Gates one (which hopefully is the correct one as it has 2 signal pins over the one in the OE original. I'm hoping it is a 'universal' with 2 pins wired in parallel).
4) As the car has no temp gauge (how stupid is that!) the owner has monitored the temp via bluetooth dongle and an app), it registers 220 degrees before the car sends a 'reduce speed' notification, so presumably the coolant temp sensor is working correctly.
5) I tried using Vida (which I seldom need to use) to trigger the ECM to send a signal to trigger the fans. Nothing happened.

Is there another sensor that can control this system like an external air temp sensor? I think that would be crazy for that to be part of the system as you want the coolant temp to control the fans and not external ambient temperature.

Any thoughts out there? BCM/ECM issue? I'm thinking ECM or wiring possibly? Car does have random BCM related issues on relation to cabin electrical systems, but this is a new issue and as far as I can see the BCM is not in the wiring loop.

Thanks,

Neil.

[Vova585]

It is an interesting issue. Please keep us posted what dealer will find. It will be hard to say anything without wiring diagram and learning theory of operation. I think it is a 3 wire input. So logically positive, negative and a network wire(probably on can low network? Not sire what system volvo using on this year). Given the fact that system works with engine off- your power and ground are ok. Now the network is a tricky one. Theoretically it should be 1 wire from ecu or bcm that commands how fast to spin the fans(4cyl engines utilize 1 fan option). I dont remember seeing a nice coolant sensor on the radiator that would be turning the fans with engine off. So possibly there are 2 separate drivers in the ecu/bcm that control engine on and engine off operation. Would be nice to see if ecm even recognize your command with vida. It should be saying something like "command on" with your telling it to spin. If it says that it is seeing the command and commands module to work, then it is corrupted driver vs some wire issue. Once again without wiring diagram it would be hard to say anything. Logically would be to disconnect the connector at ecu and fan module and check if the network wire is not shorted to ground(test light around 200-500mA with one connector and positive battery feed and other at either end of network wire) if no short found...then likely ecu itself(cuz you already mentioned that friend was able to monitor temp on his scanner).

[scot850]

You are thinking exactly what I was thinking. You are correct, 3 wire system.

1) Power direct from battery - constant live through a 30A fuse on the battery terminal
2) Ground wire
3) Signal wire, according to the wiring diagram sent directly from the ECU.

1) & 2) are large spade type connectors and the signal connecter is a much smaller connecter set between the other 2 wires and above them.

I am not computer smart enough to be able to show the wiring diagram, but if you click on the link below and then look for XC60, then 2013 (not Supplement page) it will open the wiring diagrams.
Once the document opens if you go to the index on page 3 and click on the 6cyl cooling index it will take you to page 53 with the diagram on it.

https://volvodiag.com/ewd-online-eng/

I will update as and when the car hopefully goes to the dealer. I have sent an email to the service manager to get his opinion and ok that they will look at it. I think they like the challenges I send them as they send supervised apprentices to look at the car to keep the priced down and they can learn from some real challenges! So far the have been 100% successful on the 3 challenges I have sent them and they were all stinkers!

Worst case as the car has 336 0r is it 363kkm on it, the owner will just rig a manual wire directly to the fans and a manual switch onto the dash!

Neil.

[Vova585]

I would not do the manual option. He will loose AC and also will risk overlooking the time to engage the fans, thus will overheat.
I think i would now try to see if with AC on, the fans are engaged. It appears that fans should be controlled by CCU(climate control unit) page 168. If they work- great. Your fan control module (whatever they call it) is likely OK since it responds to the command from network wire. Now to the page 53...(hate volvo diagrams) it shows the network wire going to the ECM without showing any intermediate connectors or splices(logically there should be a splice since 1 wire to ecm and 1 wire from CCM, but at control module for fan we have only 1 network wire. ).So redrawn diagrams might help here. Just by logic, it would be necessary to find this "splice" area and examin the wire integrity between it and ECM. Examine connector at ECM for corrosion. If wire is not broken or short to ground/power, ecu is a likely issue. But if the car works great otherwise.. I am more willing to bet on wire issues

[scot850]

Ha, ha!

You again think the way I am thinking. This cannot be that hard! It is a simple circuit. I will ask him if he has had the AC on or off during this time. I don't like the suggested solution either, but the car had 336 ot 363kkm on it, and has hail damage, so has little value. In fact he has suggested if I knew someone is in need of a car h would donate it for free, but only if it can be fixed.

I have spoken to the local dealer guys I know and they are willing to take on the challenge for a diagnosis. They will limit the spend and keep in touch with the owner on progress. I totally trust them as I know many of the team there including the service manager.

I'll update if we get this figured out.

Thanks again!

Neil.

[chrism]

“…. As the car has no temp gauge (how stupid is that!) the owner has monitored the temp via bluetooth dongle and an app), it registers 220 degrees before the car sends a 'reduce speed' notification, so presumably the coolant temp sensor is working correctly…..”

How is this add-on monitor connected to the engine’s temp sensor, and could it be interrupting, or in any way affecting, the sensor’s signal to the rest of the system?