SPIDER AS-FAN 3546444 - Caterpillar

Probable Causes
Diagnostic codes
Event codes
Throttle signal
Power supply for the Electronic Control Module (ECM)
Fuel supplyRecommended Actions
Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine speed, full load and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.Diagnostic Codes and Event Codes
Certain diagnostic codes and/or event codes may cause poor performance. Connect the Caterpillar Electronic Technician (ET) and check for active codes and/or for logged codes. Troubleshoot any codes that are present before continuing with this procedure.Throttle Signal
Monitor the status for "Throttle Position" on Cat ET. Verify that the status for "Throttle Position" is stable and that the engine is able to reach high idle engine speed. Refer to Troubleshooting, "Throttle Position Sensor Circuit - Test" for information that is related to troubleshooting the circuit for the throttle signal.ECM Power Supply
Inspect the circuit between the ECM and the batteries. Refer to the Electrical System Schematic. Inspect the wires, the connectors, and the components in the circuit. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test" for more information.
Inspect the circuit between the ECM and the keyswitch. Refer to the Electrical System Schematic. Inspect the wires, the connectors, and the components in the circuit. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test" for more information. Fuel Supply
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.
Check the fuel tank for foreign objects and debris which may block the fuel supply.
Prime the fuel system if any of the following components have been serviced recently:
Fuel filters
Low pressure fuel supply circuit
Unit injectorsNote: A sight glass in the low pressure supply line is helpful in diagnosing air in the fuel. For more information, refer to Systems Operation/Testing and Adjusting, "Air in Fuel - Test".
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.
Check the fuel pressure while the engine is being cranked. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for the correct test procedure. If the fuel pressure is below the specification, replace the fuel filters. If the fuel pressure remains below the specification, check the following items: fuel transfer pump, fuel pressure relief valve and fuel pressure regulator valve. Refer to Systems Operation/Testing and Adjusting for more information.