SENSOR GP-GROUND SPEED 2091280 - Caterpillar

Illustration 1 g01029309
Schematic of the CAT Data Link circuit.This diagnostic code is associated with the information sent from the Engine ECM to the Power Train ECM. The information is sent via the CAT Data Link. The CAT Data Link is connected to two inputs of the Power Train ECM. The FMI 12 means that the Power Train ECM has not received expected information from the Engine ECM.The possible causes of this diagnostic code are listed below:
The wires for the CAT Data Link to the Engine ECM are open or the wires are shorted.
The wrong software is installed on an ECM.Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0590 FMI 12 is active before performing this procedure.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 Engine ECM
The part number of the Engine ECM
The part number of the flash software for the Power Train ECM
The part number of the Power Train ECMNote: Consult your Caterpillar Dealer for the correct part numbers of the flash software.Expected Result:All the part numbers are correct.Results:
OK - All the part numbers are correct. Proceed to Test Step 2.
NOT OK - Any or all the part numbers are NOT correct. Repair: The installed Engine ECM or the Power Train ECM have the wrong part number or the incorrect software is installed. Replace the ECM with a module that has the correct part number. Refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train) - Replace" for the machine that is being serviced. Stop.Test 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 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 and/or the connector or replace the machine harness and/or the connector. Stop.Test Step 3. CHECK FOR SHORTS TO GROUND
The disconnect switch remains in the OFF position.
Disconnect the