ROD ASSEM. 8N1726 - Caterpillar

Use this procedure to troubleshoot a problem with the data link system. Also, use this procedure if one of the following diagnostic codes is active or easily repeated.
Table 1
J1939 Code and Description CDL Code and Description Comments
639-9
J1939 Network #1 : Abnormal Update Rate 247-9
SAE J1939 Data Link : Abnormal Update Rate Communication has been lost to one or more of the devices on the datalink. If multiple devices are not communicating, there is likely a problem with the data link wiring, power, or ground circuits.
639-14
J1939 Network #1 : Special Instruction 247-14
SAE J1939 Data Link : Special Instruction The affected Electronic Control Module (ECM) is missing expected parameters. If the Cat® Electronic Technician (ET) will not communicate with the ECM, refer to Troubleshooting, "Electronic Service Tool Does Not Communicate" before you begin this procedure. The procedure verifies that electrical power is being supplied to the ECM and to the service tool connector.The Systems Communication Status is located under the diagnostics tab in Cat ET. Click the "System Communication Status" option. Once the screen opens up, the information will automatically be loaded from the ECM. If there is an issue with the data link and the data link is repaired, the "Load from ECM" button will have to be clicked again to see the updated status. If there are communication issues between multiple modules, each module can be selected individually to determine which components are having communication issues. If the problem is intermittent, the "View History" button can be clicked to see all the communication faults that have previously logged.
Table 2
Cat® ET Diagnostic Code Cross Reference to Wiring Schematic
Code Description Data Link
J1939 Network #1 Can A (Global)
Illustration 1 g03885380-9 Detected Problems:Device 1 is unable to communicate on the data link.
Device 1 cannot communicate with other devices on the data link, but can communicate with the service tool, indicating a problem with the data link wiring.Device 1 is unable to communicate with Device 2 on the data link.
Device 1 cannot communicate with Device 2, indicating a problem with the data link wiring, power or ground circuit, or Device 2.-14 Detected Problems:Device 1 is unable to obtain a network address on the data link.
Device 1 is trying to claim the same address as another Device. An example of this is 2 devices being configured the same.Device 1 detects a failed address claim from Device 2 on the data link.
Device 1 detects that Device 2 is trying to claim the same address as another device.Device 1 is not receiving all expected parameters from Device 2 on the data link.
A component is configured as installed in the device, but is not installed on the application.
The incorrect component is installed.
The incorrect software file has been installed.
Table 3
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Look for active codes that are associated with the system for the diagnostic code.
Codes
Result: An associated code is active.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: An associated diagnostic trouble