Just bought the car. Dashboard says, "Tire Pressure System Needs Service." All 4 tires have the proper pressure. How can I tell if a rim does not have a sensor on it. One rim has a rubber valve stem. The other three have a chrome valve stem. Could the one with the rubber stem NOT have a sensor on it? Also I did try the "reset" button on the turn signal stem.

 

The one with the rubber valve stem sounds like it doesn't have a sensor.

 

what brand sensor should I get? Volvo OEM or will an aftermarket one do the job?

 

TPSMs have transponder frequencies. you just need to match the Volvo spec (I think its 433Mhz ). You should be able to find an after market. I know FCPEURO sells both OEM and aftermarket as does Tire Rack. Figure $60-70 for the unit, some require a stem kit to match.

 

thanks for the information mt6127