INTRUSION SENSOR

DESCRIPTION

Intrusion sensor microwave transducers are part of the premium version of the Vehicle Theft Alarm (VTA) in the Vehicle Theft Security System (VTSS). The premium version of the VTA is only available in vehicles built for certain markets, where the additional features offered by this system are required. There are two (two-door vehicles) or three (four-door vehicles) sensors used in each vehicle. These units are designed to provide interior motion detection inputs to the intrusion module, which serves as the interface between the Front Control Module (FCM), the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) and the alarm siren.

The sensors are each located within the passenger compartment of the vehicle, concealed behind the interior trim components. A sensor located in the lower center stack of the instrument panel monitors the front seating area of the vehicle. This sensor is concealed behind a lower center trim panel below the instrument panel switch pod. A second sensor is located within the swing gate and monitors the cargo area of all vehicles as well as the second row seating area of two-door vehicles. This sensor is concealed behind a molded plastic grille near the left end of the swing gate inner panel.

A third sensor is used only on four-door vehicles. This sensor is located within the center floor console to monitor the second row seating area of four-door vehicles. This sensor is concealed behind the rear trim cover of the console on the back of the console bin.

Concealed within the molded plastic sensor housing is the circuitry of the sensor which includes the microwave send and receive transducer. The housings each include integral mounting provisions dedicated to the intended sensor mounting location. Each sensor is connected through either an integral connector receptacle or an integral pigtail wire to the vehicle electrical system.

An intrusion sensor microwave transducer cannot be adjusted or repaired and, if ineffective or damaged, it must be replaced.

OPERATION

The intrusion sensor microwave transducers operate only when they are energized by the intrusion module. The sensors transmit microwave signals throughout the vehicle cabin through a transducer. The sensor then listens to the returned microwave signals as they bounce off of objects in the vehicle interior and provide input signals to the intrusion module. If an object is moving in the interior, a detection circuit in the intrusion module senses this movement through the modulation of the returning signals that occur due to the Doppler effect. The intrusion module monitors the current draw of the sensor circuits to determine the condition of the sensors and, if the draw is too high or too low, it will store a Diagnostic Trouble Code (DTC) for any fault that is detected.

The hard wired circuits for the intrusion sensor microwave transducers 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 intrusion sensors or the electronic controls and communication between other modules and devices that provide some features of the VTA system. The most reliable, efficient, and accurate means to diagnose the intrusion sensor or the electronic controls and communication related to intrusion sensor operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.