Cold Ambient Protection (Cap) - Navistar MaxxForce 7 Operation And Maintenance Manual

Operation (cont.)
COLD WEATHER OPERATION (cont.)
• Correct coolant and cooling system level
• Recommended oil grade
2. At the end of each daily operation do the following:
• Fill the fuel tank with correct fuel.
• Drain water from the fuel filter housing.
• Check oil level.
• Clean external surfaces of the engine and accessories
to prevent dirt or snow buildup.
• Clean outside and in between radiators to prevent dirt
or snow buildup.

COLD AMBIENT PROTECTION (CAP)

CAP safeguards the engine from damage caused by prolonged
idle at no load during cold weather. This feature should only be
disabled for specialized applications. Engine damage may occur
if CAP is disabled.
CAP maintains engine coolant temperature by increasing engine
rpm to a programmed value when ambient air temperature is
below 32°F ( 0°C), coolant temperature is below 167°F (75°C),
and engine has been idling at no load for over five minutes.
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SECTION 4 – ENGINE OPERATION
The engine speed continues to increase or decrease to maintain
a coolant temperature of 194°F (90°C) until the following occurs:
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Engine load is greater than 45%.
Brake pedal is applied or brake switch fault is detected.
Clutch pedal is pressed or clutch pedal switch fault is
detected (manual transmissions, if equipped with a clutch
switch).
Shift selector is moved
transmissions). Shift selector must be in neutral for CAP
to work.
Power Takeoff (PTO) switch, also used for electronic hand
throttle, is turned on and actively controls engine speed.
Accelerator pedal is pressed or Accelerator Pedal Position
(APP) fault is detected.
IST is enabled (2010 and 2011 vehicles only).
Engine Coolant Temperature (ECT) sensor fault is detected.
Intake Air Temperature (IAT) ambient temperature sensor
fault is detected.
from neutral (automatic