BODY 4M9685 - Caterpillar

Illustration 1 g03426211
Schematic of the Cat Data Link
This diagnostic code is caused by abnormal communications between the Machine ECM and the Monitor Display module through the Data Link. The update rate is not correct. Check for diagnostic codes that are related to the data link circuits. Check in the "Machine ECM" and in the Monitor Display module. If diagnostic codes are present, correct the related diagnostic codes first.For machines equipped with the E-Fence feature, reference Troubleshooting, "E-Ceiling and Cab Avoidance - Troubleshoot"A possible cause of this diagnostic code is that the Machine ECM is operating intermittently.The Data Link is an input and output of all electronic control modules. The Data Link is designed to carry communications between the electronic control modules. The Data Link is not a visible component. The Data Link consists of internal control circuits and the connecting harness wiring between the components. System Response:This failure results in events that are logged against a Machine ECM that cannot be explained directly. The Machine ECM cannot communicate with the Monitor Display module or the Machine ECM appears to communicate intermittently with the Monitor Display module. 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 flash software for the Monitor Display ECM.
The part number of the Machine ECM.
The part number of the Monitor Display ECM.Note: 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 or the Monitor Display ECM have the wrong part number or the incorrect flash software is installed. Replace the incorrect Machine ECM or the Monitor Display 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 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