BMW M5 Forum and M6 Forums banner
1 - 10 of 10 Posts

·
Registered
Joined
·
53 Posts
Discussion Starter · #1 ·
How does this work?

I had a rear tyre replaced last week due to a puncture, and when the wheel was off I could see no sensor on rim. Just curious.

By the way tyre shop did a good job of removing and replacing tyre without damaging rim. Looked hard to do. Also guy explained that Michelins are easier than Dunlops as they are a lot softer - so look out all those owners running on Dunlops when it comes to time to change!

Steve
 

·
Registered
Joined
·
907 Posts
I believe that the tire pressure warning system works by a revolution calculation after it learns your set tire pressure when you push the "set button". It can tell when the wheel revolution is greatly changed from significant air loss from one of the tires. There is no actual air pressure (PSI) reading system. I think the revolution-sensor might be built into the ABS unit.
 

·
Registered
Joined
·
352 Posts
Yup, it uses the wheel RPM.

I had a screw in a tire not long ago (in one of the second set that got stolen) and the low-pressure warning came on at 34 lbs vs
the 44 I had set it at (read tire).

Brutus.
 

·
Registered
Joined
·
14 Posts
I too recently had a problem but the warning message said "Tire Defect". I looked in the manual and found "low tire pressure" (or something like that) rather than the tire defect message. My question is whether there are actually two problem messages or whether tire defect is the same as the low tire pressure message referred to in the manual?

Thanx in advance,

Burg Hound
 

·
Registered
Joined
·
3,144 Posts
Same thing confused me at first too. Turns out that tire defect is the warning you get when you havea loss of tire pressure. Mine came on ar 32 psi, whebn i had set it at 45.

--Dan
 

·
Registered
Joined
·
15 Posts
Mine is "system inactive", when i push the button. I tried setting it the way the manual mentioned, but to no avail...any tips???
 

·
Registered
Joined
·
21 Posts
Mine also says system inactive. When I try to reset it according to the directions it still won't work! Going for my 1200 mile service Thursday. Lets see what happens.
 

·
Registered
Joined
·
1,461 Posts
The problem with the system is that it never gives you confirmation that it is active or set; but if you follow the directions, it will set the pressures correctly and you don't have to worry. The big point is to NOT hit the button again after you have the the necessary driving, because that will inactivate it, thus showing the message on the OBC. You just gotta have faith.
 

·
Registered
Joined
·
3,144 Posts
If I remember correctly, the way to set it is to (after filling your tires appropriately), you turn the key to pos 2, hold down the button for 20s, and it should give you a confirmation. after that, if you press it it disables it for that car ride i think, because i hit the button tons of times not knowing and it still detected my "tire defect" properly.

--Dan
 
1 - 10 of 10 Posts
Top