Nictrix said:
B21 said:
TPMS would / could do that as the puter knows the exact pressure directly..
TPMS wasn’t fitted to E89s till at least MY 2013..my 2011 and 2012 E89s have the earlier ABS sensor based version.
Owners manual refers…it’s called Flat Tyre Monitor and the idrive refers the FTM rather than TPMS..
I maybe used the wrong terminology for the earlier tyre monitoring system.
My X6s monitoring system seems to be the same as the earlier Z4s system without the valve sensors, so as you say probably ABS sensor based.
Still threw up a bong as soon as the tyre deflated.
So maybe the system had not been set properly in the OPs car.
That’s very possible..not properly initialised, different makes / construction, incorrect relative sizes etc.
I know I’ve had some weird effects when I inadvertently ran significantly varied front and rear rolling radius tyres from the DSC unit which is what works this out.
As I said I collected a bolt hole through a front tyre and I smelt hot rubber and mushy steering before the warning system went bong..
Does seem best on slow leaks, caught 3 such ones on the XC70 with the same system.
Glad it worked for you but I guess you already knew you had a problem?
Must have been an unpleasant experience.
As an aside one of the reasons they changed the steering geometry from positive scrub radius to negative as it means in the case of a blow out or split circuit braking failure the car tends still to track straight.