Circuit/System Description
WARNING: This page is about a different car, the 2017 Chevrolet Spark. However, it is still accessible from the selected car via links, so may be relevant.
The transmission fluid sensor is a negative coefficient thermistor mounted to the Control Solenoid Valve Assembly which has no serviceable parts.
The transmission control module supplies a 2.6 V reference signal circuit and a low reference circuit to the transmission fluid sensor. When the transmission fluid is cold, the sensor resistance is high and the transmission control module senses a high signal voltage. As the transmission fluid warms, the sensor resistance lowers and the transmission control module senses lower voltage. The transmission control module uses the transmission fluid sensor reading in order to control the torque converter clutch, line pressure adjustments and temperature compensated shifts.