GSchlice

Hi guys, I have a 2007 Q7 v6 and the both radiator fans come on when the car is turned off. They turn off when I open the door but turn right back on when I close the door. I tried starting the car and turning it back off but the problem still exists. They have pretty much drained my battery. I have unplugged both fans to keep them from draining the battery anymore. Please HELP

Gage

smith2010Q7

The one on the Radiator is G83 (ECT/Engine Coolant Temp). This goes directly to J623 (ECM/Engine Control Module) at connector T 94/pin 15 via a white wire with a yellow tracer. (white with a yellow stripe)

The one at the back of the cylinder heads on the water pipe is G62 (ECT/Engine Coolant Temp). This also goes directly to J623 (ECM) at connector T 60/pin 10 via an orange wire with a red tracer. (orange with a red stripe)

The Coolant Fans are run by the ECM via the Coolant Fan Control (FC) COntrol Module 1 and Control Module 2. They are located directly on the fan motors. (FC) Control Module 1 is the big fan, (FC) Control Module 2 is the smaller fan.


Sounds like your fan control module went bad.
You have 2 of them. Need to scan to find out which one or both. very expensive.(1400) plus a bad ground.
check your seniors. less expensive to do 1st. cost less to replace both than two fans. Do the rad 1st which will drain some coolant, then the second one on the rear of the engine. Then refill coolant. reset codes.


vw.7l.cl.g62_32l senor.pdf
Q7 Cooling System.pdf
Q7 Engine Coolant Temperature on engine.pdf
Q7 Engine Coolant Temperature Se.pdf
Q7 J623 #2 ground.pdf

GSchlice

Thank you so much smith2010Q7. I appreciate all the info. Looks like I got some work to do.

Maui19

I had this happen to my '07 4.2. It was very intermittent. I think the dealer replaced a relay and it hasn't happened since.

smith2010Q7

I had a hard time looking for the relay. The relay is less money to do 1st then Coolant senors. I want to say by your fans come on when you open the door gives me toward the relay, cause opening the door turns on your computer from sleep mode.

Maui any idea where it might be located? Under the dash? Then I will start looking in my manual.

smith2010Q7

GSchlice

I think I have found the fuse and relay. In the engine fuse & relay box. looking at a 60A or 40A/60A and a 5A.

Q7 FAN fuse].pdf

Hope this helps

bobnel

Hi all,

This EXACT radiator power drain started with me yesterday. 07 Q7 4.2

I've taken out the 3 fuses from the last post, fans are not running now and I'm recharging the battery (hopefully).

Many relays are in this box.....which one is it ?

smith2010Q7

I have look and look and cannot fine the relays in the manual. I only could fine the fuse. I hope someone else knows the info?

Sorry.

Santorin Drm pig pal

Any update guys? I just had this happen to me today. I was at a stop light and smelled an electrical burning smell. Then when I got home the fan started racing and never shut off. I pulled open the plenum fuse box and pulled the 5 Amp fuse and the 40 Amp fuse for fan control module 2 and it stopped. I left the 60 amp fuse for fan control module 1 in place. Anyone figure out where the relay is?

Maui, any chance you could ask your dealer which relay and where it was located?

Is it safe to drive the car with these fuses pulled? If Fan Control Module 1 is running, is that sufficient?