•The engine coolant temperature is greater than 106 °C (223 °F) for the C-10 or C-12. •The engine coolant temperature is greater than 111 °C (232 °F) for the 3406E. •The engine has been running for at least 30 seconds.
Probable Causes:
1) Low coolant level 2) Improper antifreeze (Wrong mix/type) 3) Air in the cooling system 4) Fan clutch failure/malfunction 5) Coolant temperature sensor/harness 6) Radiator failure 7) Radiator filler cap failure 8) Charge air cooler failure 9) Fan, fan belt, or fan shroud failure 10) Restriction in air inlet or exhaust system 11) Water temperature regulator 12) Water pump failure 13) High outside temperature or high altitude 14) Engine being run in “lug condition”
•The engine coolant temperature is greater than 103 °C (217 °F) for the C-10 or C-12. •The engine coolant temperature is greater than 108 °C (226 °F) for the 3406E. •The engine has been running at least 30 seconds.
This is a warning code only, not an actual diagnostic code. A diagnostic code will be set if the issue is serious.
The Engine Control Module (ECM) detects the following conditions:
•The coolant level sensor indicates that the coolant level is low. •The “Coolant Level Sensor” is programmed to “4 Pin” or “2-wire Float Sensor”. •The engine has less than six hours of total operating time.
Note: This diagnostic code will only occur in the first six hours of engine operation
•The intake manifold air temperature is greater than 90 °C (194.0 °F) for more than four seconds. •The engine has been running for at least 30 seconds. •The engine coolant temperature is above 99 °C (210.0 °F).
Probable Causes
1) Coolant level low 2) Debris/low air flow through charge air cooler 3) Heavy load on engine + high ambient air temperature
•The intake manifold air temperature is greater than 109 °C (228 °F) for more than two seconds. •The engine has been running for at least 30 seconds. •The engine coolant temperature is above 99 °C (210 °F).
Probable Causes:
1) Engine coolant low 2) Debris/low air flow in the charge air cooler 3) Heavy load + high ambient air temperature