Maintain your Chevrolet, Buick, GMC, or Cadillac vehicle with a Genuine GM Parts Transfer Case Range Position Sensor. Working with a motor to switch your vehicle between two-wheel drive and four wheel drive (4WD), this sensor sends a signal to the transfer case control module indicating the position of the transfer case between range changes. Only Genuine GM Parts are tested to meet GM Original Equipment standards and are designed specifically to fit your vehicle. WARNING: Cancer and Reproductive Harm