V-MAC Co-Pilot Operator's Manual 67 Idle Cooldown This feature provides a means of cooling down the engine and turbocharger. If the idle cooldown option is enabled using VCADS software and the system senses that the turbocharger may be hot, the engine will not shut down when the vehicle stops, the parking brake is set and the ignition key is turned to the OFF position. This feature allows the driver to lock the truck and walk away while still providing adequate cooldown. All switched accessories will then turn off once the engine has stopped. If this option is set, the engine can be shut down immediately by cycling the ignition key or by pressing the shutdown override switch. The idle cooldown timer is set to 3.5 minutes as soon as the engine load exceeds 25%, provided that the engine has been running at least 60 seconds. After the load drops below 25% (the lowest trigger is 35% for 2 minutes), the timer begins counting down. If the key switch is turned off before the timer expires, the engine will continue to run until the timer reaches zero. If a pyrometer is installed, the idle cooldown function will use the pyrometer reading, shutting the engine down when the temperature drops below 232°C (450°F), or after 3.5 minutes, whichever comes first. The default for this option is set at OFF from the factory. Note: The parking brake must be on for the idle cooldown function to work.
Fan Control The ON/OFF fan clutch (when equipped) can be controlled by vehicle management and control (V-MAC) IV. The following options for ON/OFF fan control are available and can be programmed using the personal computer running VCADS software:
• Minimum fan ON time for high-freon pressure while vehicle is parked • Enable optional fan override with override switch while vehicle is parked • Enable optional fan override with override switch while vehicle is moving • Optional fan override time while vehicle is moving • Optional fan engagement while a power takeoff (PTO) is engaged (not available for all software levels) Both electronic viscous and HDMS fans provide constant variable fan speed for optimum cooling. The optional engagements and overrides available with the ON/OFF fan control are also available with the electronic viscous fan.
