Engine fans draining battery...

[the cueball]

Morning all...

well I've had 2 great months of trouble free RS6 driving... surely some sort of record for me! lol

everything was great up until last night when I noticed the fans coming on really early and staying on a long time after I shut the car off....

so after I came out the gym, it was very hard to start, and just made it... went a quick run then nipped in for a curry..

came back out and totally dead.... just the dreaded 'click, click, click' noise...

got it jumped started - starts and drives no problem, no issues with the car (to me) while driving...

turn it off... fans still going mental...

car won't start again...

tried this morning just in case.... nope... completely dead...

I had a quick google about, but can't find anything specific to the RS6, but could be something like a control module???

Anyone had this happen to then? or can help?

[seaneb]

Somebody had this exact same problem not long ago. Have a search.

[seaneb]

Think it was this:

http://forum.rs246.com/viewtopic.php?f= ... hilit=Fans

[the cueball]

thanks, i saw that, but doesn't seem to be the same issue to me?

I don't have any issues with the a/c nor was his battery being drained by his issue??

I'm sure... but just scanned the car and got these errors:

2 Faults Found:
18308 - Coolant Fan Control 2
P1900 - 004 - Open or Short to Ground - Intermittent
18080 - Coolant Fan Control 1
P1672 - 004 - Open or Short to Ground

Everything else is correct with no errors. (well except ones caused by the battery drain of course)

[imacool]

It look like it's related to Audis in general. My 3.0 TDI has got similar issue, in my case the coolant fan control 1. Luckily for me the fan stays on only for 10-15 sec after ignition is switched off and only does it in wet and cold weather.
Some people from vwaudiforum.co.uk have had similar issues, one guy managed to sort it with just cleaning the fan connectors.
So it looks like some wiring loom problem.
I tried to clean the fan connector, no success, but the fan is behaving now as it is dry and warm outside. VCDS shows the same fault as in your case, my indie guy is going to scan the car with his diagnostic software, which I was told works like the audi original one, more thorough scanning with some suggested procedures to locate where the problem is.
So finger crossed he'll be able to find out what's wrong.

[mik15]

could be the coolant temperature sensor sending the wrong information...i had a similar issue where both fans would start running even though AC was off and was cold outside and they kept running for a few minutes after i would shut it off, they didn't ran out the battery, but the problem was sorted once the timing belt was done, so it must've been either the T-stat or the coolant temperature sensor in my case...

[RustyBucket]

I think that error - P1900 - 004 - Open or Short to Ground - Intermittent - is to do with the g65 sensor, easy diy fix. Although the sympotms are different it's talked about here http://forum.rs246.com/viewtopic.php?f= ... ch#p645208 and I had symptoms similar to yours with the fans running constantly. If you turn the aircon on, is econ light on and won't switch off? My battery never drained but it maybe that your battery is coming to the end of its life to so can't take the hammering.

[the cueball]

cheers for the help guys...I'll have another look at the aircon...

[the cueball]

just to finish this off in case anyone else gets the same issues...

the problem was traced to a nick/cut/break in the wire which in turn had corroded all the wiring to the fan controller/fan unit.

of course, having my luck, the wire just can't be replaced, so it's a new wire/controller/fan unit... and the front end has to come back off to fix it.

Double bad luck that the part is on back order from Audi... so will take at least a week to get here...

so that's another grand down...