TRACK AR 2429644 - Caterpillar

Illustration 1 g03426396
Schematic of the CAN Data Link CircuitThis diagnostic code is recorded when the machine ECM does not receive expected information from the Switch Panel. The possible causes of this diagnostic code are listed:
The wires for the CAN Data Link to the Machine ECM are open or the wires are shorted.
The wrong software is installed on an ECM.Test Step 1. VERIFY THE HARDWARE AND THE SOFTWARE PART NUMBERS.
Verify that the following information is correct:
The part number of the flash software for the machine ECM
The part number of the machine ECMNote: Consult your Caterpillar Dealer for the correct part numbers of the flash software.Expected Result:All of the part numbers are correct.Results:
OK - All of the part numbers are correct. Proceed to Test Step 2.
NOT OK - All of the part numbers are not correct. Repair: The installed Machine ECM has the wrong part number or the incorrect flash software is installed. Replace with the machine ECM that is incorrect. Replace the ECM with a module that has the correct part number. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace" for additional information.Flash the correct software. See Testing and Adjusting, "Electronic Control Module (ECM) - Flash Program" for additional information.STOPTest Step 2. INSPECT THE HARNESS CONNECTIONS.
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.Expected 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 3.
NOT OK - The machine harness connectors are in need of repair.Repair: Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK FOR SHORTS
The disconnect switch remains in the OFF position.
Disconnect the machine harness connectors from all electronic control modules that use the CAN Data Link.
At the machine harness connector for the machine ECM, measure the resistance between connector contact J2-50 (wire 251-YL) and all of the contacts that are used in the machine harness connector for the ECM. Perform the same measurements for J2-51 (wire 261-GN).Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each of the resistance measurements is greater than 5000 ohms. The harness circuit resistance is correct. Proceed to Test Step 4.
NOT OK - One of the resistance measurements is less than 5000 ohms. The machine