heating DODGE RAM 2500 DIESEL 2006 3.G User Guide

Operating Precautions
Avoid Overheating The Engine
The temperature of the coolant (a mixture of 50%
ethylene-glycol and 50% water) must not exceed the
normal range of the temperature gauge (240°F/116°C)
with a 16 psi (110 kPa) radiator cap.
Usually the coolant temperature indicated during opera-
tion will be to the left of center in the normal range of the
gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low coolant temperature below
the normal range on the gauge (140°F/60°C) can be
harmful to the engine. Low coolant 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.
Cooling System Tips — Automatic Transmission
To reduce potential for engine and transmission over-
heating in high ambient temperature conditions, take the
following actions:
•City Driving —
when stopped, put transmission in neutral and increase
engine idle speed.
•Highway Driving —
reduce your speed.
•Up Steep Hills —
select a lower transmission gear, but try and keep the
torque converter locked.
•Air Conditioning —
turn it off temporarily.
264 STARTING AND OPERATING

reduce the potential for transmission overheating or
failure due to excessive shifting. When operating in
“TOW HAUL” mode, 5th gear (if equipped) is disabled
and 2-3 and 3-4 shift patterns are modified. Shifts into
Overdrive (4th gear) are allowed during steady cruise
(for improved fuel economy) and automatic closed-
throttle downshifts to 3rd gear (for improved braking)
will occur during steady braking. Pressing the “TOW
HAUL O/D OFF” button a second time to select O/D
OFF will disable 4th and 5th gear completely, which
should eliminate any excessive transmission shifting.
The “TOW HAUL” or “O/D OFF” light will illuminate in
the instrument cluster to indicate when the switch has
been activated. Pressing the switch a third time restores
normal operation. If the “TOW HAUL” or “O/D OFF”
modes are desired, the button must be pressed each time
the engine is started.When To Lock Out Overdrive
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent 4–3–4 transmission shifting
occurs, press the “TOW/HAUL” button. This will im-
prove performance and reduce the potential for transmis-
sion overheating or failure due to excessive shifting.
Torque Converter Clutch
A feature, designed to improve fuel economy, has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at calibrated speeds. This may result in a slightly
different feeling or response during normal operation in
high gear. When the vehicle speed drops or during
acceleration when the transmission downshifts to second
gear, the clutch automatically disengages.
NOTE:The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1-3 miles (1.6 - 4.8 km) of driving]. Because
270 STARTING AND OPERATING

WARNING!
•Always fully apply the parking brake when leav-
ing your vehicle, or it may roll and cause damage
or injury. Also be certain to leave an automatic
transmission in Park, a manual transmission in
Reverse or first gear. Failure to do so may allow
the vehicle to roll and cause damage or injury.
•Leaving children in a vehicle unattended is dan-
gerous for a number of reasons. A child or others
could be injured. Children should be warned not
to touch the parking brake or the gear selector
lever. Don’t leave the keys in the ignition. A child
could operate power windows, other controls, or
move the vehicle.
•Be sure the parking brake is fully disengaged
before driving, failure to do so can lead to brake
problems due to excessive heating of the rear
brakes.
When parking on a hill, turn the front wheels toward the
curb on a downhill grade and away from the curb on an
uphill grade.
The parking brake should always be applied whenever
the driver is not in the vehicle.
BRAKE SYSTEM
If power assist is lost for any reason (for example,
repeated brake applications with the engine off), the
brakes will still function. However, you will experience a
substantial increase in braking effort to stop the vehicle.
If either the front or rear hydraulic systems lose normal
capability, the remaining system will still function with
some loss of overall braking effectiveness. This will be
evident by increased pedal travel during application,
greater pedal force required to slow or stop, and activa-
tion of the BRAKE warning lamp and the ABS lamp (if
equipped) during brake use.
STARTING AND OPERATING 287
5

NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips — Tow/Haul (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the “TOW HAUL OD/OFF” feature ON when
driving in hilly areas or shift the transmission to Drive
position 2 on more severe grades.
Towing Tips — Electronic Speed Control (If
Equipped)

Don’t use in hilly terrain or with heavy loads.
When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
Use speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips — Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
City Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
refer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
STARTING AND OPERATING 333
5

•Operate with transfer case in 4L when plowing small
or congested areas where speeds are not likely to
exceed 15 mph (24 km/h). At higher speeds operate in
4H.
•Vehicles with 48RE transmissions should use 4L range
when plowing deep or heavy snow for extended
periods of time to avoid transmission overheating.
•Do not shift the transmission unless the engine has
returned to idle and wheels have stopped. Make a
practice of stepping on the brake pedal before shifting
the transmission.
RECREATIONAL TOWING (BEHIND
MOTORHOME, ETC.)
Recreational Towing – 2 Wheel Drive Models
Recreational towing 2 Wheel Drive is not allowed.
Towing with the rear wheels on the ground can result in
severe transmission damage.
Recreational Towing – 4 Wheel Drive Models
CAUTION!
Failure to follow these requirements can cause se-
vere damage to the transmission and/or transfer case.
STARTING AND OPERATING 339
5

not freeing the vehicle, may lead to transmission over-
heating and failure. Allow the engine to idle with the
transmission selector in NEUTRAL for at least one
minute after every five rocking-motion cycles. This will
minimize overheating and reduce the risk of transmis-
sion failure during prolonged efforts to free a stuck
vehicle.
EMERGENCY TOW HOOKS — IF EQUIPPED
Your vehicle may be equipped with emergency tow
hooks.
WARNING!
Chains are not recommended for freeing a stuck
vehicle. Chains may break, causing serious injury or
death.
WARNING!
Stand clear of vehicles when pulling with tow
hooks. Tow straps and chains may break, causing
serious injury.
CAUTION!
Tow hooks are for emergency use only, to rescue a
vehicle stranded off road. Do not use tow hooks for
tow truck hookup or highway towing. You could
damage your vehicle.
WHAT TO DO IN EMERGENCIES 367
6

Extremely cold ambient temperature may require the
addition of a “winter front” for effective operation of the
cab heating/cooling system. Make certain that a percent-
age of the radiator is exposed for adequate air flow
through the charge air cooler and automatic transmission
oil cooler. The percentage of opening must be increased
with the increasing ambient air temperature and/or
engine load. If the cooling fan can be heard cycling
frequently, increase the size of the opening in the winter
front.
Coolant bottle level check
The coolant reserve system provides a quick visual
method of determining that the coolant level is adequate.
With the engine idling, and warmed to the normal
operating temperature, the level of the coolant on the
coolant bottle should be between the fluid level marks.
Check the coolant level whenever the hood is raised.The radiator normally remains completely full, so there is
no longer a need to remove the coolant pressure cap
except for checking coolant freeze point or replacement
with new antifreeze coolant.
WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool overheated engine! The coolant is under pres-
sure and severe scalding could result.
Drain, Flush And Refill
At intervals shown on the Maintenance Schedules, the
system should be drained, flushed and refilled. Refer to
your dealer or consult a service manual for proper
procedures.
398 MAINTAINING YOUR VEHICLE