HEAD 3749656 - Caterpillar

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.
Probable Causes
Diagnostic codes and/or event codes
Programmable parameters
Cold mode
Altitude derate
Throttle signal
Turbocharger outlet pressure sensor, rated fuel position and/or FRC fuel position
Atmospheric pressure sensor
Fuel supply
Air inlet and exhaust system
Accessory equipment
Personality moduleRecommended 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 following parameters on Cat ET:
"Throttle Position Sensor"
"Desired Speed Input Configuration"
"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: If parameters are not programmed correctly, then the engine will have poor performance.Cold Mode
Use Cat ET in order 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.Altitude Derate
The engine may be derated due to high elevation. If an altitude derate is active, the warning lamp will flash for the first 15 seconds of the derate. Connect Cat ET to the service tool connector. 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
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, "Speed Control - Test".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.Turbocharger outlet pressure sensor (intake manifold air), rated fuel position and/or FRC fuel position
With the engine at full load, monitor "Fuel Position" and "Rated Fuel Limit" on the status screen of Cat ET. If "Fuel Position" does not equal "Rated Fuel Limit" then check air inlet manifold pressure.
Verify that there are no active diagnostic codes that are associated with the turbocharger outlet pressure sensor. Monitor turbocharger outlet pressure and atmospheric pressure on the status screen for normal operation. Refer to Troubleshooting, "Analog Pressure Sensor Supply Circuit - Test".Atmospheric Pressure Sensor
Note: Atmospheric pressure is not a default parameter on the status screen. A new parameter screen must be set up in order to monitor the atmospheric pressure sensor.
Turn the Engine Control Switch (ECS) to the