Position Sensor
WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
The lumbar vertical position sensor is a potentiometer, which is attached directly to the lumbar vertical motor. The memory seat module (MSM) supplies a 5 volt reference voltage through the 5 volt reference circuit and ground through the low reference circuit to the sensor. When the motor rotates, the resistance of the potentiometer varies, changing the feed back voltage of the sensor signal to the MSM. This voltage varies from 0.25 volts to 4.75 volts. The MSM monitors this voltage to determine the vertical position of the lumbar support. When the massage function is turned OFF or canceled, the MSM will stop massage movement at the original starting position.