Gateway Module - Operation
OPERATION
The Hybrid Gateway Module (HGM) provides a communication interface between the electronic control modules (nodes) in the vehicle, as well as with the diagnostic scan tool connected to the Controller Area Network (CAN) data bus system and the nodes connected to the Hybrid Local Area Network (H-LAN) data bus system. The HGM is the central gateway that processes and transfers messages between the different bus systems. In addition, the HGM is Local Interface Network (LIN) bus compatible. It receives a direct input over the LIN bus from a humidity sensor secured to the inside rear view mirror mount on the inside of the windshield glass, which it then transmits over the CAN data bus to other electronic modules in the vehicle.
The microprocessor-based HGM also provides input and output circuitry that responds to both digital and analog inputs and provides electronically controlled higher current load outputs through lower current relay drivers. The HGM uses On-Board Diagnostics (OBD). If the HGM detects a monitored system fault, it sets a Diagnostic Trouble Code (DTC) that can be retrieved with a diagnostic scan tool through the 16-way data link connector located on the driver side lower edge of the instrument panel. The HGM connects directly to a fused battery current input and to ground, so that it remains capable of operating, regardless of the ignition switch position.
The hardwired inputs and outputs for the HGM 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 HGM, the electronic controls or communication between other modules and devices that provide features of the Hybrid Electric Vehicle (HEV) control system. The most reliable, efficient and accurate means to diagnose the HGM, the electronic controls and communication related to HGM operation, requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.