Intrusion Sensor: Operation: Transmitter

The intrusion sensor transmitter operates only when it is energized by the intrusion module. The transmitter generates ultrasonic signals into the vehicle cabin through a transmit transducer. Then the intrusion sensor receiver listens to the returning signals as they bounce off of objects in the vehicle interior and provides 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 transmitter circuits to determine the condition of the transmitter 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 transmitter may be diagnosed and tested using conventional diagnostic tools and procedures. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the intrusion module, the Controller Area Network (CAN) data bus, or the electronic message inputs to and outputs from the intrusion module. The most reliable, efficient, and accurate means to diagnose the intrusion sensor transmitter, the intrusion module, the CAN data bus and the message inputs to and outputs from the intrusion module requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.