Jeffscherer

My car (serial 8170) is three weeks old with 1900 miles. Everything is working perfectly so far. Tonight I was playing with the MMi in the garage and checked the tire pressure page on car setup. All the pressures and temps had --- and no reading. I have only checked it once before, about the first or second day I owned it 3 weeks ago and the pressures then were normal and temps showed up. Is the system not working or am I doing something wrong?? Thanks

Kian-S8

I drive an A6, not an A8. I am in TMPS business, and we supply our system to some car manufacturers. Our system is not on the Audi. However I am completely familiar with Audi's TPMS (www.beru.com). We have many things in common. There is an acceleration sensor inside the device that detects the rotation of the wheel. system has different modes in driving and parking conditions. For example when you are driving it checks the pressure every 3 to 4 seconds and transmits every 15 to 60 seconds (if everything looks OK) or transmits every 5 to 10 seconds if there is a problem. When you parked it goes into sleep mode and transmits every 15 to 30 minutes. All of the story is about to reduce the battery consumption and get a longer life out of the system. The system on the Audi lasts about 5 to 6 years if you drive 1 hour a day. System should show you the information (last set of data) when the vehicle is parked. It is not very up to date (like the driving condition), but there should be a set of data available. If you cannot see it, it might be a malfunction in its receiver module, or a bug in the MMI software. It does not sound normal to me, as I have access to the tire data all the times.

Jeffscherer

Thanks for the help. I may check with my dealer to see if they can help.

greenie

Jeff, my Corvette has the same system and unless you are actually driving the car it will not give you a readout. I doubt that anything is wrong with your system.


greenie 6625

04 A8L silver/sabre

ryoung

"approx. 80% of punctures are caused by inadequate tire pressure" .... I'm surprised they said this backwards and didn't catch the mistake, but even then it doesn't sound quite right. Just not correcting for dropping ambient temp seems to me to be the major cause of low tire pressure.

Kian-S8

TPMS on your Vette is from a different manufacturer which is much simpler than the one on the Audi. Their web site is: http://www.schraderelectronics.com
This system does not monitor the temperature and only reads the pressure (based on my last information), but they may have new transmitters that do). Both are tire-monitoring systems, but completely different design.

greenie

Oh! But I still believe that the system is operating correctly. No?


greenie 6625


04 A8L silver/sabre

Kian-S8

It takes a lot of testing to have a good system. It means cost, and it is difficult to get the money back on an OEM contract, even with Audi.

I am not working for Beru, so I am not advertising for these guys. They have a good system. It is very complex, pricey, difficult to install and customers are not well satisfied.
When you have low pressure, it means more deformation on the sidewalls. It causes the temperature to rise and tire gets hot. The heat can do something ugly, and it can be a sudden
tire failure without any noticeable change on the handling. As it gets hot, pressure increases and driver won't fell anything. Tire is not flat but temperature is much higher that it should be. Imagine that you are on the highway with lots of cars around. This is why that TPMS should be standard equipment on 2007 for all NA cars. Expect to see many Mickey Mouse system on new cars!

Kian-S8

I am not blaming your system. It is a great system, but just a completely different design. It is very simple compared to Beru. Let me know if you need more details about yours.
cheers

PaulW

I mean how often do you have to change your tire pressure? If you checked it once a month, that would be more than 99% of the people out there.

And these things keep alarming....you can't fill the tires while driving, can you? If you can't, why have the system? To let you know that you have a flat? You'll figure that out within a few miles anyways.

I guess I would rather not have the system given the choice if it has all of these problems. Really don't see an upside except that you don't have to carry a tire pressure gage in the car.

pw