Electronic Control System Gas Plus Engines – Coolant Temperature Above Normal – Gradual Overheat

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF for fault code troubleshooting.

Coolant temperature gauge or sensor is malfunctioning

Test the gauge and the sensor. Repair or replace, if necessary. Refer to Procedure 019-153.

Cold weather radiator cover or winterfront is closed

Open the cold weather radiator cover or the winterfront. Maintain a minimum of 784 cm² [122 in²] or approximately 28 x 28 cm [11 x 11 in] of opening at all times. Refer to Cold Weather Starting, Winterfronts and Shutters, Procedure 101-004 in the Operation and Maintenance Manual , C8.3G and C Gas Plus Engines, Bulletin 3666183, the Operation and Maintenance Manual , B5.9G, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666112 and in the Owners Manual C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 4021387.

Coolant level is below specification

Inspect the engine and cooling system for external coolant leaks. Repair if necessary. Add coolant. Refer to Procedure 008-018 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-018 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Lubricating oil level is above or below specification

Check the oil level. Add or drain oil, if necessary. Refer to Procedure 007-009 and 007-025 in the in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 007-009 and 007-025 in the in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Supplemental coolant additive (SCA) level is above specification or the coolant is overconcentrated with antifreeze

Check the SCA level. Verify the antifreeze concentration. Refer to Cummins Coolant Recommendations and Maintenance, Bulletin 3666162.

Charge air cooler fins, radiator fins, or air conditioner condenser fins are damaged or obstructed with debris

Inspect the charge air cooler, air conditioner condenser, and radiator fins. Clean, if necessary. Refer to Procedure 010-027 and 008-042 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 010-027 and 008-042 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Fan drive belt is loose

Check the belt tension and tighten if necessary. Refer to Procedure 008-002 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-002 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Thermostat is not correct or is malfunctioning

Check the thermostat for the correct part number and for correct operation. Refer to Procedure 008-013 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-013 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Water pump is malfunctioning

Check the water pump for correct operation. Replace the water pump if necessary. Refer to Procedure 008-062 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-062 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Cooling system hose is collapsed, restricted, or leaking

Inspect the hoses. Refer to Procedure 008-045 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-045 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Fill line or vent lines are restricted, obstructed, or not routed correctly

Check the vent lines and the fill line for correct routing and for restriction. Refer to the OEM specifications.

Radiator cap is not correct, is malfunctioning, or has low-pressure rating

Check the radiator pressure cap. Refer to Procedure 008-047 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-047 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Intake manifold air temperature is above specification

Check intake air temperature. Refer to the Intake Manifold Air Temperature Above Specification symptom tree in Section TS of the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206.

Fan drive or fan controls are malfunctioning

Check the fan drive and controls. Refer to Procedure 019-381 or Procedures 008-026 or 008-028 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedures 008-026 or 008-028 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Fan shroud is damaged or missing or the air recirculation baffles are damaged or missing

Inspect the shroud and the recirculation baffles. Repair, replace, or install, if necessary. Refer to Procedure 008-038 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-038 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Cooling system is contaminated with dirt, scale, or sludge

Clean the cooling system. Rod the radiator if necessary. Refer to Procedure 008-018 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-018 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Coolant is contaminated with lubricating oil

Refer to Procedure 008-018 and 007-003 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-018 and 007-003 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Air or combustion gases are entering the cooling system

Check for air or combustion gases in the cooling system. Refer to Procedure 008-019 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-019 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Radiator core is internally obstructed or damaged, or the check valve or J-tube is malfunctioning

Inspect the radiator and clean if necessary. Refer to Procedure 008-042 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-042 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Cooling system has insufficient capacity

Refer to the OEM service manual.

Vehicle cooling system is not adequate

Verify that the engine and vehicle cooling systems are using the correct components. Refer to Procedure 008-999 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 008-999 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.

Engine is overfueled

Check the engine fuel rate. Refer to Procedure 005-061 in the Troubleshooting and Repair Manual, C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 or Procedure 005-061 in the Troubleshooting and Repair Manual, B5.9LPG, B Gas Plus, and B LPG Plus Engines, Bulletin 3666164.