Network Communication Status

General Information The K56 Serial Data Gateway Module has the ability to learn the diagnostic addresses list of all CAN control modules that are equipped on a vehicle. This learn will help the K56 Serial Data Gateway Module identify what CAN control modules are equipped on the vehicle and what CAN buses they are on. The Network Communication Status function in the scan tool utilizes this ability to determine the communication status of CAN control modules. When the Network Communication Status procedure is performed, the K56 Serial Data Gateway Module sends out an all node all network message to halt control module communications. Then it sends out another message to all CAN control modules on a targeted CAN bus to request their communication status on that CAN bus. The Network Communication Status application can be used to: Determine what Controller Area Network (CAN) control modules are on a particular CAN bus. Determine the communication status of CAN control modules on a CAN bus. Help locate an open/high resistance fault in the serial data circuit of a targeted CAN bus. Reference Information Special Tools EL-52100 Multiple Diagnostic Interface 2 (MDI 2) Overview The Network Communication Status application can be found in scan tool (GDS2) under Vehicle Diagnostics > Vehicle Communication Diagnostics > Network Communication Status. The Network Communication Status application has multiple CAN Bus tabs, one for each CAN bus. Depending on the vehicle network configuration, some or all of these CAN Bus tabs will be displayed on top left menu: CAN Bus 1 CAN Bus 2 CAN Bus 3 CAN Bus 4 CAN Bus 5 CAN Bus 8 CAN Bus 9 CAN Bus 10 Under each CAN Bus tab, there are 3 columns: Control Module Name, Control Module Communication Status, and CAN Bus Number. The Control Module Name column displays a list of CAN control modules equipped on the selected CAN Bus tab. The Control Module Communication Status column displays the control module status as Communicating or Not Communicating. The CAN Bus Number column is just a redundant listing of the CAN Bus being tested. How to Use

Before attempting to perform the Network Communication Status procedure, verify the following: All control modules are securely connected. The EL-52100 Multiple Diagnostic Interface 2 (MDI 2) is securely connected to the X84 Data Link Connector and works properly. The scan tool (GDS2) is equipped with the latest software. The vehicle needs to be in OFF power mode to ensure the accuracy of the Network Communication DO NOT use the Network Communication Status application for CAN bus 2. At this time, the result is not accurate. All control modules on CAN bus 2 will always be displayed as Not Communicating when there is any fault on this bus. This application CAN NOT be used to detect the location of hard faults like short to voltage, short to ground, or short together on any CAN bus. All control modules will be displayed as Not Communicating when one of those fault occurs.

Ignition ON/Vehicle in Service Mode.
Install a scan tool (GDS2). Ensure the scan tool software is up to date.
Navigate to the Vehicle Diagnostics menu.
Select the Vehicle Communication Diagnostics menu.
Ignition/Vehicle OFF.
Select the Network Communication Status menu.
Upon entry, the procedure will always run against the first CAN Bus tab. It may take up to 20 seconds for the procedure to run. All other CAN Bus tabs will be disable until the procedure is complete. If clicking on another CAN Bus tab while the procedure is running, the procedure will restart again for the current CAN bus being tested. When the procedure is complete for the current CAN bus, other CAN Bus tabs will be available for selection.
Look for Not Communicating value under Control Module Communication Status tab to determine the control module that is not communicating. If only one control module is not communicating, the possible fault can be module’s ground, power, or an open in the CAN serial data circuit between that module and the K56 Serial Data Gateway Module. If multiple control modules are not communicating, but not all, there may be an open in the CAN serial data circuit at the non communicating module closet to the K56 Serial Data Gateway Module. Use the schematic for CAN bus being tested to determine the non communicating module closest to the K56 Serial Data Gateway Module. Refer to Data Communication Schematics. If all control modules are not communicating, one of these faults can occur: – A short to voltage in a CAN serial data circuit. – A short to ground in a CAN serial data circuit. – A short together between CAN serial data circuits. – An open/high resistance in a CAN serial data circuit between the K56 Serial Data Gateway Module and the closet non communicating module if the K56 Serial Data Gateway Module is at one end of the bus.

Select the next CAN Bus tab to perform the same procedure. Repeat the same process for all other CAN Bus tabs.