TPM not reliable
 

I have found on my car a 2007 X5 that the Runflat TPM is not at all reliable in fact downright flaky. I had a puncture in the tire and was running it until a new tire was available.. I checked pressure and it was at 19psi... the runflat monitor did not go off... I pumped up the tire and recalibarated and the same thing 2 days later , no alarm and 19psi... I'll be taking it to the dealer shortly to have it checked out but I can safely say that it is not to be relied upon to tell you.. I now do a visual check of tires evry now and then .. it would be much better if it was a pressure monitor rather than a basic revolution monitor.. I wonder if BMW will ever change that .. on a car that costs this $ it should be standard...:confused:

huh, i find quite the opposite in my e60, has saved me many times. Take it to the dealer, it may be a sw issue. post results please...gl

BMW has gone to actual tire pressure monitoring. I have it on my 2008 535i, with pressure transmitters in each tire.

I had the wheel-speed sensing system on previous BMW models, and never had a problem. It detected 3-4 psi drops, generally. May be something wrong with your vehicle.

Could be a bad sensor....also keep in mind that it takes into account the other tire readings as well. It will trigger with about a 5 psi difference when detected. So check the pressure of your other tires. If all of them are low, that's why you are not getting the alert........Phil

Thanks.. all the other tires were ok and I reclaibrated.. one thing I did notice is that the recalibration took a very short time to go active....I'm not convinced that the TPM works well at speeds less than 60 km/h which is what i travel in the city mostly... I'll get it checked out...

I don't quite trust mine either after a couple were 5 below the others when it was near new, but I have yet to do the simple test of deflating it and seeing if it alerts me. Also make sure it is reset after you pump it.

what did the dealer say>?

Haven't been there yet.. I'm going to book it in for Wheel alignment , get the foggginess inside my headlights checked , rear hatch springs looked at and TPM checked out at the same time..I did get a software update last time... the TPM did work well before...the latest software update has also slowed the response time when using my USB ipod quite considerably....