Go Back   AudiWorld Forums > Audi Models > Audi S4 / RS4 > S4 (B8 Platform) Discussion
Sign in using an external account
Register Forgot Password?


S4 (B8 Platform) Discussion Discussion forum for the B8 Audi S4 produced from 2009-present

Welcome to AudiWorld Forums!
Welcome to AudiWorld.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the AudiWorld Forums community today!


Reply
 
 
 
 
LinkBack Thread Tools Search this Thread Display Modes
Old 05-07-2012, 09:01 AM   #1
Audiworld Junior Member
Account #: 186758
 
Join Date: Jun 2010
Posts: 11
Default B8 S4 - TPMS

In my 2011 S4, the TPMS (tire pressure monitoring system) has never seemed to be accurate. When I would physically measure the tire pressure, it would be less than the recommended pressure, but the TPMS would never display anything. So I kind of would ignore it and continue measuring it manually (from time to time). About 1 month ago I replaced my tires (got only 17K miles on the original Pirellis). This morning I received a "TPMS system failure" message and so I reset the TPMS system thru the MMI. After that it seems to be fine. My one thought was that whatever was done during the new tire installation, may have become undone or something. Is this something to be concerned about though?
rags1 is offline   Reply With Quote
Old 05-07-2012, 10:09 AM   #2
AudiWorld Super User
Account #: 169140
 
NWS4Guy's Avatar
 
Join Date: Sep 2009
Location: Seattle, WA
Posts: 4,366
Send a message via MSN to NWS4Guy
Default

Quote:
Originally Posted by rags1 View Post
In my 2011 S4, the TPMS (tire pressure monitoring system) has never seemed to be accurate. When I would physically measure the tire pressure, it would be less than the recommended pressure, but the TPMS would never display anything. So I kind of would ignore it and continue measuring it manually (from time to time). About 1 month ago I replaced my tires (got only 17K miles on the original Pirellis). This morning I received a "TPMS system failure" message and so I reset the TPMS system thru the MMI. After that it seems to be fine. My one thought was that whatever was done during the new tire installation, may have become undone or something. Is this something to be concerned about though?
This system does not use pressure sensors, it uses the ABS to measure rotations of the wheels. You should ALWAYS reset it when you add or remove air from the tires and allow it to recalibrate. The system will not go off when the pressure is a couple PSI lower than whatever it was set at, it cannot detect this small a change, but will typically go off when the tire pressure has changed ~20% (so at 35PSI you would see a 7psi loss before alert, meaning you are at 28PSI and would not be in danger of anything more than loss of fuel economy prior to then.)
__________________
Like a surgeon with a scalpel, my S4 is a precision instrument, with which I carve and dissect my way through traffic.

2010 S4 Prem+, Quartz Gray, S-tronic, Sport Diff, B&O, Nav, Gray Birch
StopTech ST-60 BBK - Stratmosphere intake - APR Stage 1 + exhaust

**** Have USB HEX-CAN Vag-Com cable if you need someone local to mod you ****

NWS4Guy is offline   Reply With Quote
Old 05-08-2012, 09:17 AM   #3
Audiworld Junior Member
Account #: 216400
 
Join Date: Jun 2011
Location: NH
Posts: 51
Default Clarify more

Like was said, it uses the ABS sensors to sense wheel spin speed, rather than actual pressure. What matters is change in rotational speed. So for instance, if you get the car back from the tire shop, they most likely did not reset the system. So you need to go into the MMI and reset the base level. You should do this if you manually adjust pressures too. Then if one wheel starts spinning at a different speed, it will set off the alarm.
Hard Driver is offline   Reply With Quote
Old 05-08-2012, 11:14 AM   #4
AudiWorld Member
Account #: 226832
 
brooklyn86's Avatar
 
Join Date: Nov 2011
Location: Seattle, WA
Posts: 109
Default

Quote:
Originally Posted by NWS4Guy View Post
The system will not go off when the pressure is a couple PSI lower than whatever it was set at, it cannot detect this small a change, but will typically go off when the tire pressure has changed ~20% (so at 35PSI you would see a 7psi loss before alert, meaning you are at 28PSI and would not be in danger of anything more than loss of fuel economy prior to then.)
Is it that it can't detect it or it is programmed to ignore small changes?

I say this because temperature changes affect pressure and maybe its a way to ignore this fluctuation.
brooklyn86 is offline   Reply With Quote
Old 05-08-2012, 11:49 AM   #5
AudiWorld Super User
Account #: 169140
 
NWS4Guy's Avatar
 
Join Date: Sep 2009
Location: Seattle, WA
Posts: 4,366
Send a message via MSN to NWS4Guy
Default

Quote:
Originally Posted by brooklyn86 View Post
Is it that it can't detect it or it is programmed to ignore small changes?

I say this because temperature changes affect pressure and maybe its a way to ignore this fluctuation.
Not sure, but with enough temp changes it will detect it, I am sure there is some "slop" built in for false positives, but there has to be a substantial enough change in pressure to lower the rolling diameter of the wheel and allow the ABS to detect this.
__________________
Like a surgeon with a scalpel, my S4 is a precision instrument, with which I carve and dissect my way through traffic.

2010 S4 Prem+, Quartz Gray, S-tronic, Sport Diff, B&O, Nav, Gray Birch
StopTech ST-60 BBK - Stratmosphere intake - APR Stage 1 + exhaust

**** Have USB HEX-CAN Vag-Com cable if you need someone local to mod you ****

NWS4Guy is offline   Reply With Quote
Old 05-08-2012, 11:49 AM
AudiWorld
Audi R8




Paid Advertisement
 
 
 
Reply

Tags
2011, audi, b8, failure, location, monitor, monitoring, pressure, presure, s4, sensor, tire, tpms, wheel, working


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 01:28 AM.


Copyright 2014 AudiWorld.com Audi Enthusiast Community