PUMP GP-AUXILIARY 3N8561 - Caterpillar

Probable Causes
Diagnostic codes
Event codes
Throttle signal
Electrical connectors
Fuel supplyRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Check for Diagnostic and Event Codes
A. Certain diagnostic codes and/or event codes may cause poor performance. Connect the Caterpillar Electronic Technician (ET) and check for active codes and logged codes.
Codes
Result: There are no active or logged codes.
Proceed to Test Step 2.
Result: There are active or logged codes.
Repair: Troubleshoot any codes that are present before continuing with this procedure.
2. Check the Throttle Signal
A. Connect Cat™ ET to the service tool connector. View the status for the throttle position on the status screen. Operate the throttle from the low idle position to the high idle position. The status should be 0 percent at low idle and the status should be 100 percent at high idle.
Note: Diagnostic codes that are related to the J1939 data link will prevent correct operation of the throttle if the throttle position is transmitted over the data link. If there is a problem with the data link, the engine will remain at low idle until the data link is repaired.
Throttle Signal
Result: The status of the throttle signal is OK.
Proceed to Test Step 3.
Result: The status of the throttle signal is NOT OK.
Repair: Refer to Troubleshooting, "Throttle Position Sensor - Calibrate" for the correct repair procedure.
3. Check the Electrical Connectors
A. Inspect the battery wires from the Electronic Control Module (ECM) back to the battery compartment. Refer to the Electrical System Schematic.
B. Inspect the wires and the power relay. Check the power and ground connections to the ECM.
C. Refer to the diagnostic functional test Troubleshooting, "Electrical Power Supply Circuit - Test" for more information.
Electrical Connectors
Result: The electrical connectors are OK.
Proceed to Test Step 4.
Result: The electrical connectors are NOT OK.
Repair: Repair or replace any worn or damaged components.
4. Check the Fuel Supply
A. Check the fuel lines for the following problems: restrictions, collapsed lines, and pinched lines. If problems are found with the fuel lines, repair the lines and/or replace the lines.
B. Check the fuel tank for foreign objects which may block the fuel supply.
C. Prime the fuel system if any of the following procedures have been performed:
• Replacement of the fuel filters
• Service on the low-pressure fuel supply circuit
• Replacement of unit injectors
Note: A sight glass in the low-pressure supply line is helpful in diagnosing air in the fuel. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for more information.
D. Cold weather adversely affects the characteristics of the fuel. Refer to the Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation.
E. Check the fuel pressure after the fuel filter while the engine is being cranked. Refer to Systems Operation/Testing and Adjusting, "Fuel System Pressure - Test" for the correct pressure values. If the fuel pressure is low, replace the fuel filters. If the fuel pressure is still low, check the following items: fuel transfer pump, fuel transfer pump coupling, and fuel pressure regulating valve. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for additional information.
Fuel Supply
Result: The fuel