Theory Of Operation
WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.
The Body Control Module (BCM) provides a reference voltage on the hood ajar switch sense circuit. The Hood Ajar Switch switches the hood ajar switch sense circuit to ground when the hood is open. A diagnostic resistor internal to the switch is placed in parallel with the switch.