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The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere. |
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Probable Causes
- Diagnostic codes
- Event codes
- Programmable parameters
- Cold mode
- Altitude derate
- Throttle signal
- "Fuel Position" and/or "FRC Fuel Limit"
- Boost pressure sensor
- Fuel supply
- Air inlet and exhaust system
- Accessory equipment
Recommended Actions
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 logged codes. Troubleshoot any codes that are present before continuing with this procedure.
Programmable Parameters
Check the values of the following parameters on Cat ET:
- "Throttle Position Sensor"
- "Direct Fuel Control Mode"
Determine the type of throttle that is used in the application. Program the parameters to match the type of throttle that is used. Refer to Troubleshooting, "Throttle Position Sensor Circuit - Test" for more information.
Note: The engine will have poor performance if the parameters are not programmed correctly.
Cold Mode
Use Cat ET to verify that the engine has exited cold mode. A status indicator will appear if the engine is operating in cold mode. This may limit engine speed.
Altitude Derate
The engine may be derated due to high elevation. Use Cat ET to check for an active engine derate on the status screens.
Note: There are no event codes that are associated with the altitude derate.
Throttle Signal
View the status for the throttle position on the status screen of Cat ET. Operate the throttle from the LOW IDLE position to the HIGH IDLE position. The status should be approximately 0 percent at low idle and the status should be approximately 100 percent at high idle. If either indication is incorrect, refer to Troubleshooting, "Throttle Position Sensor - Calibrate".
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.
Boost Pressure Sensor, "Fuel Position", and/or "FRC Fuel Limit"
- With the engine at full load, monitor "Fuel Position" and "Rated Fuel Limit" on the status screen. If "Fuel Position" does not equal "Rated Fuel Limit" then check the inlet manifold air pressure.
- Verify that there are no active diagnostic codes that are associated with the boost pressure sensor or with the atmospheric pressure sensor.
- Monitor boost pressure and atmospheric pressure on the status screen for normal operation.
Note: Atmospheric pressure is not a default parameter on a status screen. You must manually select the parameter for the atmospheric pressure in order to monitor the atmospheric pressure sensor.
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 which may block the fuel supply.
- Check for air in the fuel. Refer to Systems Operation/Testing and Adjusting, "Air in Fuel - Test".
- Purge trapped air from the fuel system. Refer to Operation and Maintenance Manual, "Fuel System - Prime" for the correct procedure.
- 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. Refer to Systems Operation/Testing and Adjusting, "Fuel System Pressure - Test". 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.
Air Inlet and Exhaust System
- Clean plugged air filters or replace plugged air filters. Refer to the Operation and Maintenance Manual for instructions.
- Check the air inlet and exhaust system for restrictions and/or for leaks. Refer to Systems Operation/Testing and Adjusting, "Air Inlet and Exhaust System".
Accessory Equipment
Check all accessory equipment for problems that may create excessive load on the engine. Repair any damaged components or replace any damaged components.