STICK GP 5088448 - Caterpillar

Illustration 1 g01442621
Schematic for the Cat Data LinkThis diagnostic code is recorded when the Machine ECM is unable to communicate with the Engine ECM.The possible causes of this diagnostic code are listed below:
The data link wire between the Machine ECM and the Engine ECM has failed.
An open connection exists in the 30 amp fuse for the Engine ECM.
An open connection has occurred along wire 308-YL.System Response:The machine response is listed:
Calibrations of the implement control valve will not work due to unavailable engine speed input.
The "Pilot On/Off" solenoid valve will shut off when all the levers are in the HOLD position.Note: Ensure that the diagnostic code is active.Test Step 1. CHECK THE CONTINUITY OF THE FUSE FOR THE MACHINE ECM
The disconnect switch remains in the OFF position.
Remove the 30 amp fuse for the Machine ECM from the fuse panel. The fuse is located under the "loader" joystick. Locate the plastic panel that is secured by two Torx screws under the "loader" joystick.
Place the leads of a digital multimeter across the contacts of the fuse. Set the meter to read ohms and note the measurement.Expected Result:The resistance of the fuse is less than 5 ohms.Results:
OK - The resistance of the fuse is less than 5 ohms. The fuse is correct. Proceed to Test Step 2.
NOT OK - The resistance of the fuse is more than 5 ohms. Repair: Replace the fuse. Ensure that the fix has corrected the problem.STOPTest Step 2. CHECK THE COMPATIBILITY OF THE SOFTWARE.
For the correct software part numbers, refer to the Electronics Groups in the parts manual for the machine that is being serviced.Expected Result:The software is compatible.Results:
YES - The software is compatible. Proceed to Test Step 3.
NO - The software is not compatible.Repair: Flash the proper software to the appropriate ECM. Cycle the key start switch in order to initialize the new software. Ensure that the diagnostic code is no longer active. If this does not resolve the problem, proceed to Test Step 3.Test Step 3. CHECK THE +BATTERY CIRCUIT AT THE CONNECTORS OF THE MACHINE ECM .
Turn the disconnect switch to the OFF position.
Turn the key start switch to the OFF position.
Disconnect connector J1 from the Machine ECM.
Turn the disconnect switch and the key start switch to the ON position.
At the connector J1, measure the voltage between all possible sources of positive voltage to all possible sources of ground.Expected Result:The voltage measures 18 DCV to 35 DCV.Results:
YES - The voltage measures 18 DCV to 35 DCV. The voltage is correct. Proceed to Test Step 4.
NO - The voltage measures less than 18 DCV.Repair: Ensure that a proper ground exists. Also, check the circuit breakers. If the ground is proper, the power circuit has failed. Repair the power circuit or replace the power circuit. If this does not resolve the problem, proceed to Test Step 5.Test Step 4. CHECK FOR A DATA LINK CIRCUIT SHORT TO GROUND.
Turn the disconnect switch to the OFF position.
Turn the key start switch to the OFF position.
Inspect the harness connectors that