Fail Safe Cooling

The fail-safe cooling system allows limited engine operation in the event of excessive engine temperature. The fail-safe cooling mode is entered when engine temperature exceeds approximately 124°C (255°F) as measured by the cylinder head temperature (CHT) sensor.

During fail-safe cooling mode the:

• Engine coolant temperature gauge (10883) pegs to hot (H).
• Thermometer symbol will illuminate.
• Malfunction indicator lamp (MIL) (CHECK ENGINE) will illuminate.
• Powertrain control module (PCM) will disable four of the eight cylinders by turning their respective fuel injectors off. This reduced performance allows the engine (6007) to cool down.

When the engine temperature reaches approximately 166°C (330°F) the:

• Engine coolant temperature gauge remains pegged hot (H).
• Thermometer symbol will flash.
• Malfunction indicator lamp (MIL) (CHECK ENGINE) remains illuminated.
• Powertrain control module will disable all eight cylinders by turning their respective fuel injectors off, resulting in engine shutdown.