RENR5042-02 29 Troubleshooting Section Rated fuel position and/or FRC fuel position Throttle Signal Boost pressure sensor 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. If the status can not operate in the full range, refer to Troubleshooting, “Throttle Position Sensor - Calibrate”.
Fuel supply Air inlet and exhaust system Accessory equipment Recommended Actions 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. 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.
Boost Pressure Sensor, Rated Fuel Position and/or FRC Fuel Position Programmable Parameters 1. 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 air inlet manifold pressure. Check the following parameters on Cat ET: “Throttle Position Sensor” 2. Verify that there are no active diagnostic codes that are associated with the boost pressure sensor or with the atmospheric pressure sensor. “Desired Speed Input Configuration” “Direct Fuel Control Mode” 3. Monitor boost pressure and atmospheric pressure on the status screen for normal operation.
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: 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. Note: The engine will have poor performance if the parameters are not programmed correctly. Fuel Supply Cold Mode 1. 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. Use the electronic service tool to verify that the engine has exited cold mode. A status flag will appear if the engine is operating in cold mode. This may limit engine speed. 2. Check the fuel tank for foreign objects which may block the fuel supply. Altitude Derate 3. Check for air in the low pressure fuel supply system if any of the following procedures have been performed: The engine may be derated due to high elevation. Connect Cat ET to the service tool connector. Check for an active engine derate on the status screens. Replacement of the fuel filters Note:
There are no event codes that are associated with the altitude derate. Service on the low pressure fuel supply circuit Replacement of unit injectors 4. Purge air from the low pressure fuel supply circuit. Refer to Operation and Maintenance Manual, “Fuel System - Prime” for the correct procedure.