Theory Of Operation
WARNING: This page is about a different car, the 2020 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The Brake Transmission Safety Interlock (BTSI) is a safety feature that prohibits movement of the shift lever out of park unless certain conditions are met. The Radio Frequency Hub (RF-Hub) controls the BTSI solenoid. The RF-Hub module will engage the BTSI solenoid when the shifter is in Park, the module detects the depression of the brake pedal and the ignition position is in Run or Start, thus allowing the transmission shift lever to move from the park position to any other position.