Cummins N14 STC, Celect, Celect Plus – Service Manual Engine Power Output Low (CELECT™ or CELECT Plus™)

Symptom Tree  t057-155

This is symptom tree
Cause Correction

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or Section TF in the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Interview the operator to verify the complaint

Refer to the Driveability – General Information, the Driveability/Low Power Customer Complaint Form, and the Driveability Checklist at the end of Section TS. Follow the instructions on the form before continuing with this tree.

 

Electronic control module (ECM) calibration is malfunctioning

Verify the ECM calibration is correct. Check the calibration revision history for applicable fixes to the calibration stored in the ECM. Refer to the calibration history spreadsheet on QuickServe™ Online or the INCAL™ CD-ROM. Compare the calibration stored in the ECM with the engine rating and the Control Parts List (CPL), Bulletin 4021328. If necessary, calibrate the ECM. Refer to Procedure 019-032 in Section 19 of the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Programmable parameters or selected features are not correct

Check the programmable parameters and the selected features with an electronic service tool. Set the parameters and features again if necessary. Refer to the appropriate electronic service tool manual and Procedure 019-078 in Section 19 of the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Drivetrain is not correctly matched to the engine

Check for correct gearing and drivetrain components. Refer to the OEM service manual.

 

Lubricating oil level is above specification

Check the oil level. Verify the dipstick calibration and oil pan capacity. Fill the system to the specified level. Refer to Procedure 007-009 and Procedure 007-037 in Section 7.

 

Fuel grade is not correct for the application, or the fuel quality is poor

Operate the engine from a tank of known high quality fuel. Refer to Fuels for Cummins® Engines, Bulletin 3379001.

 

Air intake or exhaust leaks

Inspect the air intake and exhaust systems for air leaks. Refer to Procedure 010-024 in Section 10.

 

Fuel inlet temperature to pump is above specification

Fill the fuel tank, turn off or bypass the fuel heaters, and check the fuel cooler. Refer to the OEM service manual.

 

Air intake system restriction

Check the air intake system for restriction. Refer to Procedure 010-031 in Section 10.

 

Intake manifold air temperature is above specification

Refer to the Intake Manifold Air Temperature Above Specification troubleshooting symptom tree in Section TS.

 

Charge-air cooler is restricted or leaking

Inspect the charge-air cooler for air restrictions or leaks. Refer to Procedure 010-027 in Section 10.

 

Intake manifold pressure (boost) is below specification

Refer to the Intake Manifold Pressure (Boost) is Below Normal troubleshooting symptom tree in Section TS.

 

Throttle position sensor or circuit malfunctioning (if equipped with a throttle position sensor)

Check the throttle position sensor and circuit. Refer to the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Tachometer or speedometer is not calibrated or is malfunctioning

Compare the vehicle tachometer and speedometer readings with an electronic service tool reading. Check the calibration values for the flywheel teeth, rear axle ratio, and tire revolutions. Adjust the values if necessary. Refer to the OEM service manual.

 

Engine is operating above recommended altitude (STC engines only)

Derate the engine by 4 percent for every 300 meters [1000 feet] of altitude above 3600 meters [12,000 ft]. Refer to the Engine Data Sheet.

 

Engine protection fault code(s) inactive

Refer to Section TF in the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or Section TF in the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084. View the fault codes and the engine protection data with an electronic service tool. Refer to the appropriate electronic service tool manual.

 

Vehicle speed sensor (VSS) or circuit is malfunctioning

Refer to the appropriate electronic service tool manual. If the monitor shows speed, check the sensor and circuit. Refer to Procedure 019-090 or Procedure 019-091 in Section 19 of the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Intake manifold temperature sensor is malfunctioning

Check the intake manifold temperature sensor. Refer to Procedure 019-059 and Procedure 019-060 in Section 19 of the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or Procedure 019-059 and Procedure 019-060 in Section 19 of the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Coolant temperature sensor is malfunctioning

Check the coolant temperature sensor. Refer to the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Ambient air pressure sensor is malfunctioning (if equipped)

Check the ambient air pressure sensor. Refer to Procedure 019-134 in Section 19 of the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130.

 

Intake manifold pressure (boost) sensor or circuit is malfunctioning

Check the boost sensor and circuit. Refer to Procedure 019-061 in Section 19 of the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or Procedure 019-061 in Section 19 of the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Governor setting is not correct in the programmable parameters

Verify if the driver is accustomed to the automotive governor or the VS governor. Change the governor setting if necessary. Refer to the appropriate electronic service tool manual.

 

Fuel supply pressure is below specification

Measure the fuel supply pressure.

 

Fuel supply line restriction between the fuel pump and the injectors

Check the fuel supply line from the fuel pump to the cylinder head for sharp bends that can cause restrictions. Refer to the OEM service manual.

 

Turbocharger wheel clearance is out of specification

Check the radial bearing and axial clearances. Inspect the turbocharger. Repair or replace the turbocharger, if necessary. Refer to Procedure 010-038 and Procedure 010-047 in Section 10.

 

Engine components are not correct

Compare the Control Parts List (CPL) to the engine components. Replace components that do not meet CPL requirements. Refer to the Control Parts List, Bulletin 3379133.

 

Overhead adjustments are not correct

Check and adjust the overhead settings. Refer to Procedure 003-004 in Section 3.

 

Crankcase pressure is excessive

Check for excessive blowby. Refer to the Crankcase Gases (Blowby) Excessive troubleshooting symptom tree in Section TS.

 

Engine is operating at high ambient temperature

Use outside air to the turbocharger in hot weather.

 

Engine is operating at low ambient temperature

Check the winterfront, shutters, and under-the-hood air. Use under-the-hood intake air in cold weather. Refer to Operation of Diesel Engines in Cold Climates, Bulletin 3379009.

 

Fuel temperature is above specification

Fill the fuel tanks. Turn off or bypass the fuel heater, if equipped. Refer to the OEM service manual.

 

Fuel drillings in the cylinder head are plugged

Check for a plastic fuel passage plug blocking the fuel supply to the injectors. Refer to Procedure 002-004 in Section 2.

 

Keyswitch circuit is malfunctioning

Check the vehicle, equipment, or vessel keyswitch circuit. Refer to Procedure 019-064 in Section 19 of the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084.

 

Air in the fuel system

Check for air in the fuel system. Completely vent any air from the fuel system. Refer to Procedure 006-003 in Section 6.

 
Last Modified:  20-Mar-2012