e90 TPMS

Optimus Prime · 08-12-2009, 01:03 AM

It's my understanding that with the e90 generation there are no longer bands around the wheels that send the pressure info to the car. Instead the ABS rings report specific rotation speed and that when one tire gets low, the rotation speed increases due to circumference change.

Is this correct?

SARAFIL · 08-12-2009, 01:10 AM

Quote:

Originally Posted by Optimus Prime

It's my understanding that with the e90 generation there are no longer bands around the wheels that send the pressure info to the car. Instead the ABS rings report specific rotation speed and that when one tire gets low, the rotation speed increases due to circumference change.

Is this correct?

No, I think you have it backwards. They used to use the rotation speed of the wheels, but now due to more strict regulations they have actual tire pressure sensors mounted inside each wheel, they are on the inside of the wheel directly vehicle the valve stems. They communicate the pressure to the computer.

JST · 08-12-2009, 06:36 AM

Depends on the year. My 2007 335 had a rotation speed sensing system; my 2008 M3 has a direct sensing system like the one Sarafil describes. I know this because I had to get sensors for the M3's snow tires, and didn't have to for the 335.

TD · 08-12-2009, 07:04 AM

No sensors in my former '06.

equ · 08-12-2009, 07:05 AM

My two 2006 e90's did not have TPMS, just the rotation counter to alert...

SARAFIL · 08-12-2009, 10:36 AM

I was not sure when they changed over, but it looks like it was sometime during the 2007 model year or possibly at the beginning of 2008 based on the responses above. All new BMWs/MINIs (any model) and probably many other cars on the market these days will have a "direct" TPMS which requires a sensor in each wheel.

Optimus Prime · 08-12-2009, 11:36 AM

Quote:

Originally Posted by SARAFIL

I was not sure when they changed over, but it looks like it was sometime during the 2007 model year or possibly at the beginning of 2008 based on the responses above. All new BMWs/MINIs (any model) and probably many other cars on the market these days will have a "direct" TPMS which requires a sensor in each wheel.

Are these a different sensor than the band that used to be around the inside of the wheels? I thought that's what they had originally, then switched to using the ABS rings. Maybe they've again switched that and they have a sensor on the inside of the valve.

Terri Kennedy · 08-12-2009, 11:53 AM

Quote:

Originally Posted by Optimus Prime

Maybe they've again switched that and they have a sensor on the inside of the valve.

That's what it looks like. I just checked the BMWUSA configurator (stock 328i) and it comes with Style 282 wheels. The ETK page for that wheel shows a transmitter in the valve stem. See attached PDF.

SARAFIL · 08-12-2009, 11:56 AM

These are the actual sensors that they use.

Terri Kennedy · 08-12-2009, 12:08 PM

Quote:

Originally Posted by SARAFIL

These are the actual sensors that they use.

Yikes! $79.14 each? And that's just for the electronics module; doesn't even come with the funky valve stem, which is another $13.90!

Any idea why that part has a note that says "Important! Limited storage life: Please observe expiry date on parts label."?

08-12-2009, 01:03 AM	#1
Optimus Prime Carmudgeon Join Date: Apr 2005 Carmudgeonly Ride: Golf TDi Location: Peoria, IL Posts: 3,283	e90 TPMS It's my understanding that with the e90 generation there are no longer bands around the wheels that send the pressure info to the car. Instead the ABS rings report specific rotation speed and that when one tire gets low, the rotation speed increases due to circumference change. Is this correct? __________________ Jason

08-12-2009, 10:36 AM	#6
SARAFIL I like BMWs Join Date: Oct 2003 Carmudgeonly Ride: X5 M50 / M550 Location: Boston, MA Posts: 5,789	I was not sure when they changed over, but it looks like it was sometime during the 2007 model year or possibly at the beginning of 2008 based on the responses above. All new BMWs/MINIs (any model) and probably many other cars on the market these days will have a "direct" TPMS which requires a sensor in each wheel. __________________ 2020 X5 M50i -- Alpine White / Coffee Leather 2020 M550i -- Carbon Black / Beige Leather

08-12-2009, 11:56 AM	#9
SARAFIL I like BMWs Join Date: Oct 2003 Carmudgeonly Ride: X5 M50 / M550 Location: Boston, MA Posts: 5,789	These are the actual sensors that they use. Attached Thumbnails __________________ 2020 X5 M50i -- Alpine White / Coffee Leather 2020 M550i -- Carbon Black / Beige Leather

08-12-2009, 06:36 AM	#3
JST 195 Join Date: Oct 2003 Posts: 24,614	Depends on the year. My 2007 335 had a rotation speed sensing system; my 2008 M3 has a direct sensing system like the one Sarafil describes. I know this because I had to get sensors for the M3's snow tires, and didn't have to for the 335.

08-12-2009, 07:04 AM	#4
TD Founder emeritus Join Date: Oct 2003 Location: Maryland Posts: 21,007	No sensors in my former '06.

08-12-2009, 07:05 AM	#5
equ Alphanumeric Join Date: Aug 2005 Carmudgeonly Ride: 981S, 340i Posts: 9,584	My two 2006 e90's did not have TPMS, just the rotation counter to alert...