132 STARTING AND OPERATING
Idle Shutdown
This feature can be enabled so that the truck will automati-
cally shutdown when the truck has been idling for a set
period of time when the engine is at operating tempera-
ture. Idle time can be set in 5 minute increments between 5
and 60 minutes. See your local authorized dealer to enable
this feature.
NOTE: The idle shut down timer is disabled while the PTO
is active.
Programmable Maximum Vehicle Speed
(Chassis Cab Only)
This feature allows the owner to set a maximum vehicle
speed for the vehicle. The 3500 Series maximum vehicle
speed can be set between 40 mph (64 km/h) and 87 mph
(140 km/h). The 4500/5500 Series maximum vehicle speed
can be set between 40 mph (64 km/h) and 85 mph (136
km/h). See your local authorized dealer to enable this
feature.
NOTE: DO NOT set the maximum vehicle speed to a value
greater than what the vehicle tires are rated for.
Operating Precautions
Avoid Overheating The Engine
The temperature of the engine coolant (antifreeze) (a mix-
ture of 50% ethylene-glycol and 50% water) must not
exceed the normal range of the temperature gauge 240°F
(116°C) with a 21 psi (145 kPa) coolant pressure cap.
Usually the engine coolant (antifreeze) temperature indi-
cated during operation will be to the left of center in the
normal range of the gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low engine coolant (antifreeze)
temperature below the normal range on the gauge 140°F
(60°C) can be harmful to the engine. Low engine coolant
(antifreeze) temperature can cause incomplete combustion
which allows carbon and varnish to form on piston rings
and injector nozzles. Also, the unburned fuel can enter the
crankcase, diluting the lubricating oil and causing rapid
wear to the engine.