2006 B7 A4 radiator Fans question

[Eddy Jo]

what would cause the fans to go on and drain the battery when the car is not running? Had to have a new battery put in today by AAA cause the car was deader than a doornail- when they tested it , the fans for cooling came on as soon as the tech hooked up the new one (and they go off when you open the door, interesting!) Past history, we have had a lot of rain in the past day or so and maybe something shorted out when I went thru some puddles? Is there a relay that is easily tested? Phil? any ideas?[headbang]

[fly300kts]

Relay might me stuck but tough to test due to internal condensators
How many miles on the car?
I would replace it

Phil

[Eddy Jo]

Phil, this is why I mention your name- thanks Pal! Car has about 210k on it and the relay has never been replaced- The quick fix (temporarily) is to pull # 4 fuse so it does not run while sitting idle (not running) - how you making out with all that rain- heard it rained 24" in 24 hours- Fla is going to sink!

[fly300kts]

Not a drop of rain here in the Miami area

Phil

[jarocki]

Go figure, this is EXACTLY what happened to my 2008 A4 2.0T today. Will keep checking back if anyone chimes in with a fix. From the limited reading I've done (just started searching now), most signs point to the ran control module needing to be replaced, or the relays under the ECU being fried from water entering the housing.

**Edit** It has rained pretty consistently for the past week or so... Just picked the car up 2 weeks ago with 74k on the clock

[Inked]

Not a drop of rain here in the Miami area

Phil

It's been pouring up here for 3 days

[blackie-b7]

I had this issue about a year ago. The ECU box tends to puddle up with water since is it right under the wiper cowl and the cooling fan relay shorts out. Its not easy to get to but I am 90% sure that is your problem. I bought a new one although after taking the old relay apart, I could have probably got away with just cleaning it. I didn't have anymore drained battery issues until about two months later when it snowed. The ECU box had water in it again. I was fed up with it so I drill a tiny hole at the bottom of the ECU box and haven't had any issue ever again.

[80sGuy]

Could be the thermostat too.

[fly300kts]

I need to stop replying to these threads [headbang]:

While installing the brakes yesterday, I serviced the AC and my fans were acting weird
Quick scan:

001152 - Coolant Fan Control Circuit 1
P0480 - 002 - Electrical Malfunction - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 0
Fault Frequency: 2
Reset counter: 255
Mileage: 241941 km
Time Indication: 0

Freeze Frame:
RPM: 2965 /min
Load: 55.7 %
Speed: 139.0 km/h
Temperature: 92.0°C
Temperature: 33.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.335 V

$350 later, this will be the second time I am replacing the fan module, 2 years apart
I really think the internal design is weak and does not support the heat generated in that area

Phil

[kegobeer]

That sucks, Phil. I think I was lucky that my P0480 was just a bad fan and not the controller. Maybe the fan is causing the controller to continually fail?

[fly300kts]

No because the fans are passive the way the system is designed (no feedback sent to the controller)
The behavior is different this time:

When AC selected ON but not LO, for fans start at really low speed for about 8 seconds and then stop.
What is scary is the system pressure, close to 110 psi

Phil

[jarocki]

Just an update on my car:

I won't have a place/time to go under the ECU till next week, but for the last two days the fan issue has stopped. The only thing I know I have done "differently" is turn the HVAC to a temp above 70* and turn it off before removing the key.

Maybe it's just coincidental, but after I did this the car has been behaving fine...

[Dondbg]

No because the fans are passive the way the system is designed (no feedback sent to the controller)
The behavior is different this time:

When AC selected ON but not LO, for fans start at really low speed for about 8 seconds and then stop.
What is scary is the system pressure, close to 110 psi

Phil


Hello. I having exactly the same issue. "" When AC selected ON but not LO, for fans start at really low speed for about 8 seconds and then stop."" By any chance do you remember what was the issue ?
Relay, FCM,

[pezgoon]

Hello. I having exactly the same issue. "" When AC selected ON but not LO, for fans start at really low speed for about 8 seconds and then stop."" By any chance do you remember what was the issue ?
Relay, FCM,

He said in two posts above that it was the FCM

Also I read your other thread and what those replying to it said, they said the a dying fan can kill the FCM but Phil says above that it will not, take your pick if you wanna replace the fans or FCM but if there's no feedback then I'd probably replace the FCM
You might have good luck with a used one, many part outs going on *hint hint*


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[Dondbg]

I just done couple of more test via VCDS and noted the following :
If I test fan from engine controller Both run 0-100% but if I ran it from HVAC controller nothing moves. .... noted that the aux fan is a bit noisy.
starting the engine cold and aircon on both fans run and live data Radiator Fan (V7) - Requested Value is almost equal to actual value but once the coolant temp reaches ~76 more or less both shuts and I can see the pressure of refrigerant starts to build up and air cooling starts to degrade inside the cabin , the fans will kick in and spins full shortly and shut...
Looking at the live data I see Radiator Fan (V7) - Requested Value is 0 and actual is some reading which is not accurate.

Temp of coolant reached 95 and fan didn't start.

aftermarket FCM ?
Any good ? I'm have sourced a used one will see.


Audi A4 B7 avant 2.0T Quattro 2008.

[pezgoon]

I just done couple of more test via VCDS and noted the following :
If I test fan from engine controller Both run 0-100% but if I ran it from HVAC controller nothing moves. .... noted that the aux fan is a bit noisy.
starting the engine cold and aircon on both fans run and live data Radiator Fan (V7) - Requested Value is almost equal to actual value but once the coolant temp reaches ~76 more or less both shuts and I can see the pressure of refrigerant starts to build up and air cooling starts to degrade inside the cabin , the fans will kick in and spins full shortly and shut...
Looking at the live data I see Radiator Fan (V7) - Requested Value is 0 and actual is some reading which is not accurate.

Temp of coolant reached 95 and fan didn't start.

aftermarket FCM ?
Any good ? I'm have sourced a used one will see.


Audi A4 B7 avant 2.0T Quattro 2008.

Ya I'd try FCM, since you tested them and they worked fine under vag com that points to the "brain" being at fault


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[wriscolf]

Just out of curiosity. Do you know the threshold for the fans to kick in? My coworkers Civic threshold for fans are ridiculously high but its normal for those cars.

[jadedj]

I had this exact same issue with my B7 Avant and after replacing the battery and reading all about the causes, it was water in the ECU. As someone else on an Audi blog wrote, "99% of the time, it's water in the ECU." I took the cover off, removed all the relays, dried the bottom out by leaving it in the garage for a few days, replaced the relay ($25), sealed the small crack along the back of the cover and VIOLA, the car runs great. I was almost ready to bring it to the stealership too!

[Dondbg]

I had this exact same issue with my B7 Avant and after replacing the battery and reading all about the causes, it was water in the ECU. As someone else on an Audi blog wrote, "99% of the time, it's water in the ECU." I took the cover off, removed all the relays, dried the bottom out by leaving it in the garage for a few days, replaced the relay ($25), sealed the small crack along the back of the cover and VIOLA, the car runs great. I was almost ready to bring it to the stealership too!

Tried to get to ecu box but the damn wiper arms , couldn't take them offfff


Audi A4 B7 avant 2.0T Quattro 2008.

[pezgoon]

Tried to get to ecu box but the damn wiper arms , couldn't take them offfff


Audi A4 B7 avant 2.0T Quattro 2008.

You can atleast pry the side up and inspect in there


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[Dondbg]

You can atleast pry the side up and inspect in there


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I ordered a jaw puller so I can take the wiper arms. tried to pry box from the side but was worried I'm might bend or deform it.


Audi A4 B7 avant 2.0T Quattro 2008.

[Okedokey]

Penetrating oil. Use it. You are supposed to re grease them regularly anyway.

[Dondbg]

Penetrating oil. Use it. You are supposed to re grease them regularly anyway.

Tried that and left to soak overnight and it didn't move.


Audi A4 B7 avant 2.0T Quattro 2008.

[pezgoon]

Tried that and left to soak overnight and it didn't move.


Audi A4 B7 avant 2.0T Quattro 2008.

Ya didn't help me either, nor did a hammer, I was prying so hard the whole car was shaking

You need a wiper arm puller hah which is what the proper procedure says too


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[Dondbg]

Ya didn't help me either, nor did a hammer, I was prying so hard the whole car was shaking

You need a wiper arm puller hah which is what the proper procedure says too


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I've see videos where they use a jaw puller , if that what you mean then it's on the way.
This fu$& b1tch is stuck.


Audi A4 B7 avant 2.0T Quattro 2008.

[pezgoon]

I've see videos where they use a jaw puller , if that what you mean then it's on the way.
This fu$& b1tch is stuck.


Audi A4 B7 avant 2.0T Quattro 2008.

Hahaha yep, I knew it would be [:p]

Yes a jaw puller/windshield arm puller, it is actually a tool I found out! I'm guessing it's a more common problem than I had known before

Here is the one AutoZone sells and is relatively simple

http://m.autozone.com/test-scan-and-specialty-tools/wiper-arm-tool/oem-windshield-wiper-arm-puller/191681_0_0

buuuut here's one from summit racing which is a jaw puller style

https://m.summitracing.com/parts/lil-54150?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-lisle&gclid=CL-wivnIl9MCFYiKswod3DoKuA


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[Dondbg]

Hahaha yep, I knew it would be [:p]

Yes a jaw puller/windshield arm puller, it is actually a tool I found out! I'm guessing it's a more common problem than I had known before

Here is the one AutoZone sells and is relatively simple

http://m.autozone.com/test-scan-and-specialty-tools/wiper-arm-tool/oem-windshield-wiper-arm-puller/191681_0_0

buuuut here's one from summit racing which is a jaw puller style

https://m.summitracing.com/parts/lil-54150?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-lisle&gclid=CL-wivnIl9MCFYiKswod3DoKuA


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Thanks.


Audi A4 B7 avant 2.0T Quattro 2008.

[jadedj]

Ya it's definitely not easy. I jiggled the wiper arm a bit and it came right off. That's the easy part, getting the box top off is hard, required some prying and twisting

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[pezgoon]

Ya it's definitely not easy. I jiggled the wiper arm a bit and it came right off. That's the easy part, getting the box top off is hard, required some prying and twisting

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Lol we were talking about the difficulties of getting the wiper arm off [>_<]


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[Dondbg]

Lol we were talking about the difficulties of getting the wiper arm off [>_<]


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Let me get to the box first :)


Audi A4 B7 avant 2.0T Quattro 2008.

[pezgoon]

Let me get to the box first :)


Audi A4 B7 avant 2.0T Quattro 2008.

Haha agreed, but I just noticed your in New Zealand so you may have an easier time because of the what and no salt usage, I dread the day I have to get mine off [mad] north east coast USA


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[snatchman]

Can someone point me in the direction of where the fan control module is located and a correct part number? I am having the same issues and would like to start there.

[fly300kts]

Above the fans, right side of the hood latch

Phil

[pezgoon]

Can someone point me in the direction of where the fan control module is located and a correct part number? I am having the same issues and would like to start there.

https://www.ecstuning.com/b-genuine-volkswagen-audi-parts/radiator-fan-control-module-600w/8e0959501ag/


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[Dondbg]

Can someone point me in the direction of where the fan control module is located and a correct part number? I am having the same issues and would like to start there.

I've just fixed mine, looks like the module was faulty , anyway I replaced the whole thing and used a second hand part.
My advise just swap the whole thing as replacing only the module will involve splicing wires which personally I'm not in favour of doing that.




-------------------------------------
Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

[dalmation53]

It's been pouring up here for 3 days

yeah it has and is been gloomy too.