Intrusion Transceiver Module: Description
An Intrusion Transceiver Module (ITM) is part of the Export premium version of the Vehicle Theft Alarm (VTA) in the Vehicle Theft Security System (VTSS). The Export premium version of the VTA is only available in vehicles built for certain markets, where the additional features offered by this system are required. The ITM is located in the passenger compartment, on the lower surface of the headliner near the center of the vehicle. This component is designed to provide interior motion detection, and serve as an interface between the Body Control Module (BCM) and the alarm siren module.
The ITM is concealed beneath a molded plastic trim cover that approximates the size and shape of a typical dome lamp housing. Rather than a lens, the ITM features three sets of louvered openings. Each of the louvered openings is covered on the inside by a single molded black plastic sight shield that extends the length of the center rib for appearance. The module is secured to a molded plastic mounting bracket above the headliner. Besides the ITM, the trim cover also conceals two plastic pins integral to the mounting bracket that are used to secure the bracket to the headliner with two stamped nuts that are installed from below. An adhesive-backed foam pad is installed above the ITM bracket between the headliner and the roof panel to provide additional headliner stabilization and support for the ITM mounting. Two small notch-like service holes on the rear edge of the trim cover afford access to the two integral rear latches of the ITM for service removal.
Concealed within the housing is the electronic circuitry of the ITM which includes a microprocessor, and an ultrasonic receive transducer. A molded plastic connector containing six terminal pins that is soldered to a small circuit board and extends through a clearance hole in the left front corner of the ITM housing, and an ultrasonic transmit transducer housing extends from the center of the right side of the ITM housing. Both the transmit transducer on the right side of the module and the receive transducer on the ITM circuit board are aimed through two small round holes in the sight shield of the trim cover. The ITM is connected to the vehicle electrical system by a wire harness that is integral to the headliner.
The ITM unit cannot be adjusted or repaired and, if faulty or damaged, must be replaced.