Centinel System – Repair Manual – Engine Brake – Low Retarding Power or Slow to Activate

Interview the operator to verify the complaint

Refer to 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 forms before continuing with this tree.

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the Troubleshooting and Repair Manual, CM870 Electronic Control System, Signature™ and ISX Engines, Bulletin 4021334, or Troubleshooting and Repair Manual, Electronic Control System Signature™, ISX, and QSX15 Engines Bulletin 3666259, or Troubleshooting and Repair Manual, Power Generation Control Systems QSX15, QSK23, QSK45, QSK60, QSK78, and QST30 Engines, Bulletin 4021419 for fault code troubleshooting.

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 electronic service tool manual.

Engine is cold

Allow the engine to warm to operating temperature. If the engine will not reach operating temperature, refer to the Coolant Temperature Below Normal symptom tree in Section TS.

Engine brake adjustment is not correct

Adjust the engine brakes. Refer to Procedure 020-004 in Section 20.

Engine brake on/off switch or circuit is malfunctioning

Check the engine brake on/off switch and circuit. Refer to Procedure 019-034 in Section 19. Procedure 019-035 in Section 19. These procedures are found in the Signature™ and ISX CM870 Electronic Control System, Troubleshooting and Repair Manual, Bulletin 4021334. Procedure 019-034 in Section 19. Procedure 019-035 in Section 19. These procedures are found in the Signature™, ISX and QSX15 Electronic Control System, Troubleshooting and Repair Manual, Bulletin 3666259. Procedure 020-012 in Section 20. Procedure 020-015 in Section 20.

Engine brake solenoid, harness or connectors are loose, broken or have an open circuit

Check the engine brake circuit, solenoid, and harness connectors. Check the engine brake harness, solenoids, and grounding for continuity. Refer to Procedure 019-136 in Section 19. This procedure is found in the ISX and ISM CM871 and CM876 Electronic Control Systems Troubleshooting and Repair Manual Bulletin 4021560. Procedure 020-004 in Section 20. Procedure 020-012 in Section 20. Procedure 020-015 in Section 20.

Engine electrical ground is malfunctioning

Check for poor battery and chassis grounds. Check ground wires or cables for loose connections. Check the following grounds, make sure they are secure, clean, and on a non-painted surface: engine block ground, chassis (or frame rail) grounds, ECM grounds, alternator and starter negative posts. Disconnect and clean battery cable connections.

Air in the lubricating oil system

Check the oil level. If the level is high, contact a Cummins® Authorized Repair Location.

Lubricating oil leak (internal)

Check the engine brake control valve and the engine brake piston. Refer to Procedure 020-017 in Section 20 and Procedure 020-019 in Section 20.

Engine brake solenoid(s) is malfunctioning

Refer to
Procedure 020-012 in Section 20.

Engine brake control valve(s) is malfunctioning

Check the engine brake control valve(s). Replace the engine brake control valve(s) if necessary. Refer to
Procedure 020-017 in Section 20.

Engine brake lubricating oil passage is restricted

Check the engine brake assembly for restriction. Refer to Procedure 020-004 in Section 20.

Turbocharger is malfunctioning

Perform diagnostics to determine if the turbocharger has failed. Replace the turbocharger as necessary. Refer to Bulletin 4021334, for ISX CM870, Section TT, 70-t02-1001, Guided Step 6. For ISX CM871 refer to Bulletin 4021560, Section TT, 16-t02-1001a, Guided Step 6.