hold the TPS button until the yellow light comes on. Then drive and after about 10 seconds it will go out. The system should now be calibrated for your current pressures
There is no sensor as such for tyre pressures. The ABS/DSC system notices that one wheel is going faster than the others because a deflated wheel has a smaller diameter than normal. The system Kabal describes works for me. Although I only did it to see if it worked. I have never had the flat tyre warning come on and it should only come on if one wheel is going at a different speed to the opposite side (going flat or under inflated). I suppose if you have a new tyre on one side and old on teh other it might pick up the difference in remaining tread?
bryden, its not the 19's that setting the sensors off.
Make sure that you are using the correct size tyres, if the profiles are the wrong size, they will trigger the tpm!