Vehicle Theft Security Hood Ajar Switch - Operation

OPERATION

The standalone swich is a normally closed switch that is held open as the spring-loaded switch plunger is depressed by the striker on the inner hood panel. When the hood is opened, the spring-loaded switch plunger extends from the switch body and the switch contacts are closed.

The hood latch mounted switch is a normally open switch that is held open by the spring loaded plunger when the hood is fully latched. When the hood is opened the latch lever depresses the spring loaded plunger into the switch body and the switch contacts are closed.

The hood latch mounted switch has no adjustment but the standalone switch has a self-adjustment feature that includes an integral stop on the shaft of the plunger and a ribbed, ratcheting sleeve-like retainer ring at the top of the switch body from which the plunger extends. With the switch mounting collar secured in its mounting bracket, the plunger is depressed by the striker on the hood inner reinforcement as the hood is closed. As the plunger is depressed, the plunger stop contacts the top of the retainer ring and it is driven downward, ratcheting through the switch mounting collar until the hood is fully closed and latched. The ribs on the retainer ring are engaged within the mounting collar to maintain this adjusted position.

The hood ajar switches as well as the hard wired circuits between the switches and the TIPM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls or communication between modules and other devices related to hood ajar switch operation that provide some features of the export vehicle theft or domestic remote starter systems. The most reliable, efficient, and accurate means to diagnose the electronic controls and communication related to hood ajar switch operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.