indoor

I scanned the Auto Transmission with VCDS and got the following
2 Faults Found:
00652 - Gear Monitoring
27-00 - Implausible Signal
00526 - Brake Light Switch-F
27-00 - Implausible Signal

I changed the brake light switch with a genuine one($55 from dealer), but I might have wasted my money since after doing some research Ross Tech says:
Special Notes
FAQ 2.7. Many Automatic Transmission Control Modules will show a DTC 00526 or 17087 that indicates a faulty brake light switch. This can be ignored and will not appear if you press the brakes once before checking for Fault Codes.

Now for the 00652 code Ross Tech has a long list of possible causes(solutios)
Check Automatic Transmission Fluid (ATF) Level
Check/Clean/Replace Vehicle Speed Sensor (G68)
Check/Clean/Replace Gearbox Speed Sensor (G38)
Check/Replace Multi-Function Switch (F125)
Check/Replace Clutch and/or Valve Body

Assuming the ATF fluid is low, how do I add fluid and what type?
Where the hell is the vehicle speed sensor? Is it by the wheel? Can this sensor even do that to the transmission?
I'm assuming the gearbox speed sensor is on the transmission and I'll check it when I check the fluid?!

Any input welcome! Thanks!

GTA_Driver

The vehicle speed sensor, aka crank position sensor, is attached to the bell housing above the driver's side axle.

Check out the tech section on checking and changing the ATF.

indoor

Do I have to remove the outer axle to access the speed sensor? I'm assuming the wire going down inside the bell housing is connected to the speed sensor?!

EDIT: I found some ATF check/replace articles through google, one on a passat, and one on an a8(I thought it might be on audiworld, though)...So prolly similar on a6...Thanks!

Edit #2: I found the wheel speed sensor. It's behind the rotor looking from the front of car. I cleaned the passenger side one without removing it(pretty much just the outside part...) But how does it come out? Do I just yank it straight out?

indoor

Some updates: for the record...

I checked the TCM under passenger's foot well and it was dry.
I decided to change the transmission fluid and while I'm there check all those sensors. So far they look good, BUT it looks like the previous owner hit the bottom of the transmission oil pan. Not good... And it looks like that caused a leak right in that area of the transmission. And about 5 of the screws were loose there too. Anyway, I only drained about 3 quarts of fluid. So it was definitely low on fluid(hopefully that was just the problem and the tranny is not toast)...

And that's it for now...

indoor

After I changed the ATF and filter (I used the blauparts kit), the tranny is back to normal. It's only been a week though, but I hope it stays like this
The point of this update is that after researching the 00652 code, even though a lot of mechanics suggested buying a new (used) tranny, it's not always the case. If you can do the fluid change yourself, it's worth trying to see if the fluid level/quality is the culprit...
Good luck!

tester123

I hope you've checked the level at proper temp. with vag-com. Apparently, from what I read the level is critical for proper operation and longevity of trans. Great that you posted the update/resolution!