Cooling Fan Not Working - P0481 Error
 

Hi,

My cooling fan doesn't work. It's the type with a silver resistor but doesn't work on either low or high speed, so the car (facelift 2.5 Auto) overheats when stationary (only done to test).

TOAF gives me:
P0481 - Cooling fan 2 control circuit malfunction
- short to ground
- no signal detected
- sporadic error
- fault present

Does that mean I need to replace the fan unit, or might there be errors in the wiring before the current gets there? I have a few other "short to ground" errors as well affecting other components (e.g. K bus). Just not sure where to start looking now.

Toaf checks all three speeds as per original spec, the 2 speed came later. Odd that even your high speed isn't working - have you moved the slider within the Toaf checking process to roughly halfway?

Try the demist check too.

Regards

Thanks - I hadn't noticed that within TOAF - will give it a go. Is it possible it's reporting an error for the speed I don't have?
I've tried both the demist/ECON method for low speed and the "let the temp get up to 115C" method for high speed - neither gets the fan going.

Yes, quite possible, others have reported the same. If moving the slider doesn't help then you probably need a new fan but usually 2 speed fans don't suffer from the same brush wear of the 3 sp fans and most owners just need to fit a better type of resistor (gold, available at DMGRS).

Good luck

ps Check your VIS motors too, if you don't know how just ask.

Funnily enough, the next error was
P1472 - Variable intake manifold actuator 2 - valve always open
- short to ground
- sporadic error

Could that be related at all?

Not generally related - best thing is to open the bonnet, start Toaf, same menu as the fan, select VIS balance / power, press the start button and listen: you should hear four distinct sweeps of each motor in turn. No sweeps or just a click - contact Stocktake on here who renovates these motors to a standard better than new.

Regards

TOAF is set up for the original three speed fan. The three speed fan is low, medium and high, two speed fan if low and high. Because TOAF can't get a response from the medium speed in a two speed fan it sees it as a fault.

Hello Richard,

If you are DIY-minded and are willing to have a go with a multimeter, we can find out what's wrong with your 2 speed fan.

What's your car's mileage?

Simon

Hi Simon,

Yes, I have a multimeter and will give anything a go - mileage is 116k.

That's great Richard.

116k is a high mileage so it may be that brush wear is responsible for your loss of all speeds, particularly if the air conditioning has been run continuously during the car's life. To find out we will need access to the fan control box which means taking off the front bumper assembly. This isn't as daunting as it might seem and Arctic's pictorial guides cannot be bettered! As you'll need lots of room to manoeuvre, the weather forecast is good over the next week for working outside. :}

Let me know when you've done that and you never know, you might discover something simple like a broken wire. ;) But if everything is intact we'll get started on some electrical measurements.

Simon