Engine Idling - Dodge 2015 RAM Owner's Manual

224 STARTING AND OPERATING

Engine Idling

Avoid prolonged idling, long periods of idling may be
harmful to your engine because combustion chamber
temperatures can drop so low that the fuel may not burn
completely. Incomplete combustion allows carbon and
varnish to form on piston rings, engine valves, and
injector nozzles. Also, the unburned fuel can enter the
crankcase, diluting the oil and causing rapid wear to the
engine.
If the engine is allowed to idle, under some conditions
the idle speed may increase to 900 RPM then return to
normal idle speed. This is normal operation.
NOTE: For EVIC/DID messages related to the vehicle's
exhaust system, refer to "Electronic Vehicle Information
Center (EVIC)" or "Driver Information Display (DID)"
for further information.
Idle-Up Feature — Automatic Transmission Only
The driver-controlled high idle speed feature will help
increase cylinder temperatures and provide additional
cab heat, however, excessive idling may still cause the
exhaust aftertreatment system to not properly regenerate.
Extended periods of idle time should be avoided.
The Idle-Up feature uses the speed control switches to
increase engine idle speed and quickly warm the vehi-
cle's interior.
1. With the transmission in PARK, the parking brake
applied, and the engine running, press the speed
control switch to the ON position, then press the SET
switch.