BRACKET 3904997 - Caterpillar

SAE J1922 Data Link - Abnormal Update Rate
Illustration 1 g03326541
Schematic of the CAN A Data Link circuit
The CID 0247 diagnostic code is associated with the SAE J1939 Data Link. The FMI 09 diagnostic code is recorded when the power train ECM stops receiving information on the "CAN data Link".Note: The resistance of the wires for the "CAN A" circuit should measure approximately 120 ohms between circuit components.Test Step 1. INSPECT THE HARNESS CONNECTIONS.Refer to Troubleshooting, "Electrical Connector - Inspect ".
Turn the disconnect switch to the OFF position.
Inspect all harness connections that are related to the "CAN Data Link". Make sure that the connectors are clean and tight.
Check the connectors for proper mating. Ensure that all the seals are present and in place.
Check the harness for signs of damage or abrasion.
Check the wires at the connector. Ensure that the wires are secured tightly into the connector. Take care not to pull the wire out of the connector.
Check the exposed wires at the connectors for nicks or signs of abrasion.
Check for moisture inside the connector.
Check the connectors for dirty contacts or corroded contacts.
Check each pin and each socket of the machine harness connectors. Ensure that the contacts are properly installed. The contacts should mate correctly when the two pieces of the connector are placed together.
Check the 120 ohm terminating resistor connector for the following:
Moisture
Corrosion
Damaged terminals
Loose connectionsExpected Result:The machine harness connectors are tight and free of corrosion. Results:
OK - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 2.
NOT OK - The machine harness connectors are in need of repair.Repair: Repair the machine harness or replace the machine harness. STOPTest Step 2. CHECK FOR SHORTS TO GROUND
The disconnect switch remains in the OFF position.
Disconnect the machine harness connectors from all ECMs that use the CAN data link.
At the machine harness for the power train ECM, measure the resistance between frame ground and connector contacts J2-67 (wire F711-GN(Green)) and J2-68 (wire F712-GY(Grey)) of the data link circuit. Expected Result:The resistance