This is a typical tire pressure sensor on GM
vehicles. This is used on TPM systems in your
Chevrolet, Buick, Pontiac, Cadillac, GMC and
Oldsmobile cars and trucks.
There a differences between this part depending on
model and year. Other sensors have a black stem.
These must be pulled through the rim with the tire
The picture above is the type with the nut on the
outside of the rim. The tire still needs to be removed
from the rim to replace.
Tire Pressure Monitor System (TPM)