RADIATOR & FAN GP 3774468 - Caterpillar

Illustration 1 g02303515
Schematic for the Cat Data Link
This diagnostic code is recorded when the Transmission/Chassis ECM (Tractor) is unable to communicate with the Caterpillar Monitoring System ECM through the Cat Data Link. There is no response from the ECM or the response is incorrect.System Response:This failure results in events that are logged against an ECM that cannot be explained. The Transmission/Chassis ECM (Tractor) cannot communicate with this ECM or the ECM appears to work intermittently.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 Transmission/Chassis ECM (Tractor)
The part number of the flash software for the Caterpillar Monitoring System ECM
The part number of the Transmission/Chassis ECM (Tractor)
The part number of the Caterpillar Monitoring System 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 Transmission/Chassis ECM (Tractor) or the Caterpillar Monitoring System ECM have the wrong part number or the incorrect flash software is installed. Replace the incorrect Transmission/Chassis ECM (Tractor) or the Caterpillar Monitoring System ECM with a module that has the correct part number. Flash the correct software. See the Testing and Adjusting, "Electronic Control Module (ECM) - Flash Program" section for additional information.STOPTest Step 2. INSPECT THE HARNESS CONNECTIONS.
Turn the disconnect switch and the key start 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:
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 TO GROUND.
The disconnect switch and the key start switch remain in the OFF position.
Disconnect the machine harness connectors from all electronic control modules that use the Cat Data Link.
At the machine harness for the Transmission/Chassis ECM (Tractor), measure the resistance between frame ground and connector contacts J1-7 (wire 892-BR(Brown)) and J1-8 (wire 893-GN(Green)) of the Cat Data Link circuit. Expected Result:The resistance is greater