Switch, Hood Ajar: Operation

The standard equipment hood latch mounted hood ajar switch is actuated by the hood latch mechanism and the hood latch striker. When the hood is closed and properly latched, the latch mounted hood ajar switch is an open circuit. When the hood is open or only partially latched, the hood ajar switch is a closed circuit. The switch has a 1 kilohm diagnostic resistor connected in parallel to the switch contacts located between the two switch terminals. The hood ajar switch is hardwired in series between a return circuit and a signal circuit of the Body Control Module (BCM).

The BCM reads the hardwired hood ajar switch input through an internal pull-up resistor, then uses this input to control other electronic functions and features of the vehicle. Some of these features may include the remote start system and the Vehicle Theft Alarm (VTA). The BCM may also send electronic hood ajar switch status  messages to other electronic modules in the vehicle over the Controller Area Network (CAN) data bus.

The latch mounted hood ajar switch as well as the hardwired inputs and outputs of the switch may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information.