Transmission Range Sensor
WARNING: This page is about a different car, the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Cadillac Escalade ESV, and 2018 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
The transmission range sensor is a hall-effect that has two PWM output signal circuits. The engine control module (ECM) supplies a 5 V reference circuit and a low reference circuit to the transmission range sensor. Sensor 1 signal circuit is an input to the TCM. Sensor 2 signal circuit is an input to the ECM. Each transmission gear range position has different duty cycle values of the PWM signal. The TCM uses the information from sensor 1 signal to determine what transmission gear range the vehicle operator has selected and apply the clutches for that gear. The ECM uses the information from sensor 2 signal to determine if the transmission is in park or neutral to enable the starter motor for engine cranking.