Brake shift interlock system
WARNING: This page is about a different car, the 2006 Dodge Grand Caravan, 2006 Dodge Caravan, and 2006 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.
The brake shift interlock solenoid receives power from both high side and low side controls inside the FCM. The high side control is on the same circuit as the EATX module power, and the low side control comes through pin 47 of the FCM connector. The solenoid is controlled by the low side driver when the brake pedal is pressed. Both circuits are continuously monitored for malfunctions.