If I buy new tires and put them(new tires and wheels) on the same position they came off from,will the TPMS have to be reprogrammed? If so ,why? If they are run w/o reprogramming,will any harm be done? Thanks

 

I assume you will take the existing sensors out of your old wheels and mount them in the new wheels.

The TPMS computer in the car can hold 4 sensor ID#s. It knows which sensor is on which corner of the car due to the order in which they are programmed during the sensor relearn procedure.

Your current sensors are logged into the TPMS memory and the TPMS knows which one is on which corner of the car.

If you use the current sensors in your new wheels, if they are put back on the same corner of the car they came off from, then nothing at all will need to be done.

If they get mixed up and end up on different corners of the car, they'll still work and the DIC will display pressures, but the DIC reported position won't correspond with actual position, i.e., if the DIC says "Left Front 23 psi" it might be talking about the Right Rear if that's where the sensor that was in the LF is now located.

If you put new sensors in and run them without programming of course you won't know if you lose pressure in a tire, and you'll probably have problems putting the AH into Comp mode or turning it off completely.

With runflats, you really need sensors. The stiff sidewalls just don't give the handling feedback when flat that you get when a normal tire loses pressure - at least while going straight down the highway. If your runflat loses pressure and you don't know it, you can completely lose control if you try to take a corner in a spirited manner.

Bob

 

Each sensor has a unique ID which the on board computer recognizes. As long as you're careful to insure that the sensors go into the new wheels & are mounted at the same corner, you'll be OK. The programming of the C6 sensors requires a special Dealer instrument, but it's a 10 minute job which most Service Managers seems willing to do gratis if you ask nicely in case you do get them mixed up.

 

If I read your post correctly, it seems you are only changing your tires on existing rims. All of the above is correct, however just changing tires is easy and keep the tpms on the same corner of the car they came off of.