Tire Pressure Sensors
 

I have OE Pirelli 255/40R19 tires on my 2006 A8. For winter driving I replaces them with an 18" set of chrome wheels and 235/50R18 Nokian Hap. The Nokian tires are great for Quebec winter driving. Unfortunately I don't have tire pressure monitoring sensors on the winter wheels...thus the annoying sensor warning. My dealers don't know how to turn it off. Any advice/comment would be much appreciated.
Cheers

Re: Tire Pressure Sensors
 

Well you can get some tire pressure monitoring sensors on the winter wheels.

Re: Tire Pressure Sensors
 

That's because you can't turn a safety feature off in the normal fashion. VCDS Can disable it because of what you need to do. Wheels with TPMS can be setup on the existing system and adapted easily using your MMI. Read the book.

What you should be aware of is this. Measure the circumference of your original tires and match the new setup with something very close. If you don't, expect the speedo to read incorrectly and the ABS controller to do the same.

Re: Tire Pressure Sensors
 

If you have direct TPMS then you will need 4 sensors/valves for your winter wheels. I ordered 4 from Tire Rack for my other car.
Wheel diameter only applies to indirect TPMS.

Re: Tire Pressure Sensors
 

Measure the circumference of your original tires and match the new setup with something very close. If you don't, expect the speedo to read incorrectly and the ABS controller to do the same.

Here's an English calculation.

The formula relating road speed and engine rpm is

mph = (rpm X cir) / (gear X final X Eighty Eight)

where rpm = engine rpm
cir = tire circumference, in feet
gear = gear ratio of your car
final = final drive ratio of your car
88 = combines several conversion factors

For example, an Audi 90 Quattro. Its tires are 195/60VR-14, so the calculated circumference works out to be 72.92 inches or 6.08 feet. Its final drive is 4.11:1, its 5th gear is 0.79:1, so their product is 3.25 and the rest is a quick calculation away:

mph = (rpm X 6.Zero Eight) / (3.25 X Eighty Eight) = 0.0213 rpm

Ie: the Audi will do 21.3 mph for every 1000 rpm in 5th gear.

To work the equation the other way and to find engine rpm for a given road speed, you want to solve for rpm:

rpm = (mph X gear X final X Eighty Eight) / circumference

At 60 mph, the Audi is revving a calculated 2822 rpm, within a few percent of the computer's calculated 2750 rpm.

Re: Tire Pressure Sensors
 

I think the 2006 A8 has direct pressure sensors inside the wheels, so no need for calculations. Red G8R is correct in assessing that for direct pressure read sensors, all you may need is additional, newly installed sensors that radio transmit the pressure reading. These sensors will need to be compatible with the TPMS receiver so that will neeed to be examined. Older systems measured pressures by counting tire revolutions/rotations compared with other wheels. Low pressure meant more rotations so an alarm was generated. No exact pressure reading was provided. That was how indirect systems operated. Direct pressure reading systems circumvent all of these problems. I'd order the OEM pressure sensors to ensure compatibility with the MMI/TPMS system in your A8. Ask dealer but check around for aftermarket parts as well.

Re: Tire Pressure Sensors
 

You might want to check the Audi World dot com Forums site. One the A8 D3 pages, an owner by the name of Brozee has show how to eliminate the TPS system on the MMI using the Ross-Tech VAG software, connector, and a laptop. I haven't done it, but it looks simple!

I'd post a link, but I haven't yet had 5 posts on this Audi Canada site!

Send me a Private Message or an e-mail if you have trouble, and I'll send you the link.

Gary--

Re: Tire Pressure Sensors
 

Gary,
I hope you did take note that the original post was from 10-05-2008, 04:12 PM no sense in responding to resolved issues 4 years ago

Re: Tire Pressure Sensors
 

1Move,

Well, I didn't see that. BUT the post is there for anyone who might do a search on lowering an A8 in the future. New guy trying to be helpful, old eyes didn't look for or see the posted date!!!

Gary-

Exactly Gary! Its valuable information for the archive, even though this one is for those annoying TPMS sensors. :P

I'm still shocked at how unbusy this forum is though, lol.

Re: Tire Pressure Sensors
 

I checked out another A8 today. I was playing around with the MMI and noticed you can disable them. Ha! Sweet! XD

Re: Tire Pressure Sensors
 

Sorry for reviving an old topic:

2013 B8 S4, in the MMI, TMPS doesn't exist, however I know with vag-com you can activate it (I did it on my 2011 S4) but with the 2013 I keep getting an error message.

Question is whether or not perhaps the car doesn't even have the sensors in the ABS and this is why the code keeps throwing errors.

On my 2011 S4, I was able to activate TPMS but once when I got a flat tire the TPMS light never went on - quite odd.

Can anyone comment?

Re: Tire Pressure Sensors
 

I activated the TPMS through Vag Com with my 2013 S4. Everything seemed to work well, but I actually haven't tested it yet. I set the program to accept the current tires pressures (after checking them) but I never let out air to ensure it was working. I should do that this weekend ;)

Re: Tire Pressure Sensors
 

Can you share with me the code you used?

Re: Tire Pressure Sensors
 

I followed the 3G instructions here:

AudiEnthusiasts Master

Re: Tire Pressure Sensors
 

Pretty odd. I used the same instructions.

I'll try again. Funny thing was on my 2011 S4 I successfully enabled TPMS, then I blew a tire over a pot hole, continued driving for 5 more minutes yet the TMPS light never went on.

I am starting to think S4s are not shipped from factory with sensors in the ABS.

Re: Tire Pressure Sensors
 

I know that you have to have the right abs code

If you have 1AT on your options code sticker your good to go activating the tpms


If your option code shows 1AS then it won't work :(

Re: Tire Pressure Sensors
 

That's an excellent point.

Do you know the diff between the two codes and why would one car have one and another car have a different code?

Re: Tire Pressure Sensors
 

I'm not sure why the two or what's different. I got lucky with both of my B8 S4s and had the 1AT code and had no problem activating my tpms it worked perfectly. We did it on a buddies A4 and it didn't work, that's when I noticed his code was 1AS.

After doing a little (very little) research I found out about the two codes and the issue with the 1AS one.

Which one do you have listed on your option sticker in your service manual?