GUARD AS 3337265 - Caterpillar

Illustration 1 g01163786
This diagnostic code is recorded when the ECM does not receive any harness code information from the Caterpillar Monitoring System.The possible causes of this diagnostic code are listed:
The data link wires in the harness are open, shorted or there is a bad connection.
The flash software that is installed is incorrect.
The Caterpillar Monitoring System has failed. This is unlikely.System Response:The machine response is listed:
All functions will be disabled if the implement ECM has never received a valid harness code.
If the ECM had previously received a valid harness code and is not receiving one now, the implements will be disabled. Note: Ensure that the diagnostic code is active.Test Step 1. VERIFY THE HARNESS CODE
Enter mode 1 in the monitoring system and verify that the harness code for your machine is correct. Refer to the monitoring system manual for a list of the harness codes.Expected Result:The harness code that is in the monitoring system is correct.Results:
OK - The correct flash software is loaded and the harness code is correct in the monitoring system. Proceed to Test Step 2.
NOT OK - The harness code is not correct. The flash software that is installed for the ECM is not the correct software.Repair: Contact your Caterpillar dealer for the correct software application for your machine. Install the correct software. Refer to Testing and Adjusting, "Electronic Control Module (ECM) - Flash Program" for more information on installing the correct software. Stop.Test Step 2. INSPECT THE DATA LINK HARNESS CONNECTIONS
Turn the disconnect switch to the OFF position.
Inspect all harness connections that are related to the Cat 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:
YES - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 3.
NO - The machine harness connectors are in need of repair.Repair: Repair the machine harness or replace the machine harness. Stop.Test Step 3. CHECK THE DATA LINK CIRCUIT FOR A SHORT TO GROUND
The disconnect switch remains in the OFF position.
Disconnect the machine harness from all electronic control modules that use the Cat Data Link.
At the machine harness for the implement ECM, measure the resistance between contacts J1-9 (wire 944-OR) and J1-3 (wire 945-BR) of the Cat Data Link and frame ground. Expected Result:The resistance is greater than 5000 ohms.Results:
YES - The resistance is greater than