Engine Speed Surges at Low or High Idle

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF for fault code troubleshooting.

Fuel level is low in the tank

Fill the supply tank. Refer to the OEM service manual.

Fuel inlet restriction

Check for fuel inlet restriction. Refer to Procedure 006-020 in the Troubleshooting and Repair Manual N14 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666142, or the Troubleshooting and Repair Manual M11 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666139.

Air in the fuel system

Check for air in the fuel system. Refer to Procedure 006-003 in the Troubleshooting and Repair Manual N14 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666142, or the Troubleshooting and Repair Manual M11 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666139.

Moisture in the wiring harness connectors

Dry the connectors with Cummins electronic cleaner, Part Number 3824510.

Engine position sensor (EPS) or circuit is malfunctioning

Check the engine position sensor and circuit. Refer to Procedures 019-038 and 019-039.

Vehicle speed sensor (VSS) or circuit is malfunctioning

Check the vehicle speed sensor and circuit. Refer to Procedures 019-090, 019-091, and 019-093.

Alternator is malfunctioning

Temporarily disconnect the alternator and run the engine. Replace the alternator if necessary. Refer to the OEM service manual.

Vehicle ground circuit has an intermittent open circuit

Check the ground circuit for loose or broken connections. Refer to the OEM service manual.

Fuel pump is malfunctioning

Check the fuel pump output pressure, pulsation damper, and pressure regulator. Replace the fuel pump if necessary. Refer to Procedures 005-016, and 005-031 in the Troubleshooting and Repair Manual N14 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666142, or the Troubleshooting and Repair Manual M11 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666139.

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 Click here to see ecm_calibration_rev_history.xls

on QuickServe® Online or the INCAL™ CD-ROM. Compare the calibration stored in the ECM with the engine rating and Control Parts List (CPL), Bulletin 4021326 or 4021327. If necessary, recalibrate the ECM. Refer to the appropriate electronic service tool manual and Procedure 019-032.

Idling with excessive load

Use the PTO feature for loaded conditions at low engine speeds. Refer to in the Operation and Maintenance Manual N14 Plus Series Engines, Bulletin 3666136 or the Operation and Maintenance Manual M11 Plus Series Engines, Bulletin 3666143.

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 Click here to see ecm_calibration_rev_history.xls

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 4021326 or 4021327. If necessary, recalibrate the ECM. Refer to the appropriate electronic service tool manual and Procedure 019-032.

Camshaft end clearance is excessive

Check the camshaft end clearance. Refer to Procedure 001-008 or 001-065 in the Troubleshooting and Repair Manual N14 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666142, or the Troubleshooting and Repair Manual M11 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666139.

Injector is malfunctioning

Perform the automated cylinder performance test. Replace injectors as necessary. Refer to Procedure 006-026 in the Troubleshooting and Repair Manual N14 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666142, or the Troubleshooting and Repair Manual M11 Series Engines (STC, CELECT™, CELECT™ Plus Models), Bulletin 3666139.