The ECM detects the following conditions:

•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