2003 MCS
I got a flat yesterday in one of the stock run flat (car has under 13k miles).

The stinkin' tire pressure monitor never came on. The way I figured it out was that the car seemed to follow grooves in the pavement more than normal and I had the windows open, so I heard a little more tire roar than normal. When I checked the pressure, it was at zero...

Anyway, how can I test the tire pressure monitor to figure out why it didn't come on?

Thanks,

John S.

 

It doesn't have a tyre sensor in the wheel. Mini's use the wheel speed sensors used by the AbS system to detect the slight change in the rolling circumferance of the tyre wheel combo when the tyres are underinflated. To check the system hit the brakes hard to activate the ABS, if the ABS kicks in the system is working

 

Thanks...

The ABS is definitely working.

How much time at low inflation (like pretty close to 0 psi) does it take for the ABS to decide a tire is deflated rather than you're just turning? I went about 4 or 5 miles with the tire very flat and the light never came on. It does come on with the ignition at start up, so it's not burned out.

Thanks

 

This system cannot detect a blow out or a very slow leak.... small design flaw. Could be the reason the light never came on. Is it possible the light was never reset a previous time when air was added to the tires?

 

How do you reset the system? When I drove the car, after the tire repair, I checked all of the pressures (40 front 30 rear) and the DSC light and the TPWS lights were both on...

I pressed the reset and nothing happened, but then after letting the car sit again, now everything is back to normal (no DSC light unless I turn it off and no TPWS light)...

John S.

 

Hey there,

You need to press and hold the reset button ( in front of the E-brake handle on the base of the rear console ) for a few seconds ( untill the tire press. light stays on ) - then drive the car for a bit.

My system does not trigger untill I have a tire at least 10 psi lower than the rest. I still check my tire press. once a week and reset the system whenever I add air.

Good luck

 

OK, thanks, that's what I did, but I was expecting the light to go out immediately. So basically, I shoul reset the system on some sort of regular basis...

Thanks for the help

 

I would suggest resetting after you check tire pressures and they are okay. The owner's manual says to reset the system after filling the tires with air. Unfortunately, this type of flat detection system has limitations and cannot provide instant warning of a flat.

 

I wish the MINI had the direct system mounted on the inside of each rim. I bet the tire needed to be flat like when the rim's touching tarmac, before the TPMS ligth would come on. This kind of system also doesn't tell you the psi per tire. I am considering upgrading to aftermarket TPMS system with a sensor inside. Have anyone done that?

 

That's not true. I have had my tire light come on when there differential is about 8-10psi. The system works but as discussed it's not instant on. My guess is that the system was properly initialised and hence it had to run almost flat to record the difference.

 

Ours worked when one front was 27 psi and the other tires were all 32-33 psi. This system does work, and is much less expensive than actual tire pressure sensors. It isn't, however, perfect.
It is OK (to me) considering we're running run-flats and they can be driven with NO air. You should be able to feel the difference though.
A tire pressure gauge is still the right thing to use to monitor tire pressures, IMO.
Jim