Section 717 (Audio/Video/Entertainment/Connectivity (Service Information)): Operation
The Security Gateway Module (SGW) is the Controller Area Network (CAN) gateway between the radio, telematics modules, Data Link Connector (DLC) and the other vehicle CAN modules. An SGW failure could prevent the radio from powering up, telematics module from communicating or a scan tool from communicating with the vehicle. For additional information on the SGW. Refer to MODULE, SECURITY GATEWAY (SGW), DESCRIPTION .
Use of the MIT019 Multi-Media Tester may cause the radio screen to go blank.
The base audio system components are designed to provide audio entertainment and information through the reception, tuning and amplification of locally broadcast radio signals in Amplitude Modulating (AM) and Frequency Modulating (FM) commercial frequency ranges.
Some audio system components operate on battery current received through a fuse in the rear Power Distribution Center (PDC) on a fused B(+) circuit and monitor electronic ignition status message inputs received over the Controller Area Network (CAN) data bus network so that certain functions remain active regardless of the ignition status. Other components operate on battery current received through the rear PDC on a fused ignition RUN/ACC circuit so that they will only operate when the status of the ignition switch is RUN or Accessory (ACC).
Certain audio system components receive electronic message inputs over the CAN - Interior High Speed (IHS) data bus. While the Radio Receiver Module (RRM) is also connected to the CAN-Chassis (CAN-C) data bus, the RRM is not a CAN gateway. All electronic message outputs of the RRM are carried over the CAN-IHS data bus. When the RRM monitors a problem in any of the audio system circuits and components, or in any of the Bluetooth® transceiver circuits, it stores a fault code or Diagnostic Trouble Code (DTC) in its memory circuit.
The SGW is in the audio and telematics systems to provide security against certain types of attacks and threats from the scan tool, telematics and entertainment buses, which can put the rest of the vehicle's buses at risk of intrusion. The SGW lies electrically between the vehicle on one side, and the Data Link Connector (DLC), telematics and entertainment systems on the other side. The main function is to gate messages from one bus to another. The SGW monitors the B(+) Feed, switched ignition feed, CAN circuits, software and hardware for any concerns.
The hardwired circuits between components related to the audio system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds. For proper wire repair, and connector repair procedures. Refer to STANDARD PROCEDURE , REMOVAL , and INSTALLATION .
However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls and communication between modules and other devices that provide some features of the audio system. The most reliable, efficient and accurate means to diagnose the electronic controls and communication related to audio system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.