I got this from the Alex@tirerack closed sticky thread


BMW’s indirect system will not affect the choice of switching aftermarket wheels or tires. The system runs off of the ABS/wheel-speed sensors which “count” the number of revolutions of each tire. If the right-front tire is low (25psi) it will spin faster than the left-front tire (35psi), so the ABS system will recognize this change and alert the driver with a flashing light near the gauge cluster and possibly a loud chime.


My 09 Miini with the basic tire and wheel gives me a warning when the pressure is at 35.
That seems a bit high.
I think the recommended PSI is around 37
Should I just put them all at 40?

 

Your MINI has actual sensors in the wheels. The ones Alex was talking about are for earlier MINIs.

 

A 25% loss sets off the light.

You "reset" the light to set the "current " pressure. Use the BC button to do this (gen II cars).

 

I've found the sensor version is much more sensitive than the ABS version. The sensor version can detect 4-5psi. It depends on what the pressure was when you reset it. I've had the ABS version down 10psi and not alerting. Again, it depends on the pressure when you reset it.

 

Thanks folks for all the help

Turns out my gauge is off by two pounds.
I went to Costco and set the pressure to 38 (which read 40 on my gauge)

Checked the door and the recomended cold pressure is 33.
That's probably where they were when the sensor gave it's warning.

So I'm a little confused

Am I driving around with over inflated tires?

What's a BC button? I usually reset with the Tire /Reset button on the turn signal.
I always try reseting before I put air in.
Sometimes it works sometimes it doesn't .

thanks again for all the help
bob

 

No, reset after you put air in.

I also want to mention that the current system in the MINI (as required by law) is really meant as a safety feature to give warning for preventing blowouts. The sensor reading is crude and you shouldn't rely on it to maintain optimum pressure.

 

BC stands for "Board Computer". It's what you have already been using to reset. Always reset after you air up!!

 

Sorry , I guess I wasn't clear. I always have to reset after putting in the air at service stations.
I just try to reset before to see if it sticks. Like I said, Sometimes it does, sometimes it doesn't .

Yesterday at Costco was the first time it actually reset itself.
That must be from the accurate method their air machine has that turns off after hitting the right psi.

so again.. Do you all think I'm running on too high a psi at 38 when the door says 33? Is there a way to reset to 33?

 

My door says 38. Which model/tire do you have? You can reset to whatever you want.

 

38 will give you a firmer ride... better MPG at the cost of possible increased tire wear.. (frankly, I run all my cars a little higher.. I prefer the ride..)

That 33 is based on Mini "engineering" and has nothing to do with the tire type or brand..

 

I believe its stands for "Body Control" or "Body Computer".