2008 DODGE RAM 2500 GAS light

Slight changes in engine speed or power may be noticed
when the air conditioning compressor is on. This is a
normal occurrence as the compressor will cycle on and
off to maintain comfort and increase fuel economy.
The mode control (at the right of the
control panel) can be set in any of the
following positions:
NOTE:To improve your selection choices, the system
allows you to operate at intermediate positions between
the major modes. These intermediate positions are iden-
tified by the small dots.Recirculation Modes (Panel or Bi-Level)
Select the recirculation modes when
the outside air contains smoke, odors,
high humidity, or if rapid cooling is
desired. This feature allows for recir-
culation of interior air only. Air flows
through the panel only, or through
both the panel and floor vents depend-
ing on the selected mode (panel vs bi-level).
NOTE:Selecting a Recirculation Mode does not neces-
sarily consume more fuel than normal A/C mode.
Panel
Outside air flows through the outlets located in the
instrument panel.
Bi-Level
Outside air flows through the outlets located in the
instrument panel and at the floor.
262 UNDERSTANDING YOUR INSTRUMENT PANEL

Air Conditioning and Heating Operation
To turn on the Air Conditioning, set the fan control at any
speed and press the snowflake button located on the
control panel. Conditioned air will be directed through
the outlets selected by the mode control. A light in the
snowflake button shows that the air conditioning is on.
Press the button a second time to turn the air condition-
ing off.
A/C Pushbutton
With the fan control in the ON posi-
tion, pushing the A/C button turns on
the air conditioning compressor. An
indicator light on the button shows
that the Air Conditioning compressor
is on. Conditioned air is now directed
through the mode outlets selected.
Pushing the button a second time turns the compressor
OFF.
Recirculation Pushbutton
Pushing the Recirculation button al-
lows interior air to recirculate continu-
ously in any position except defrost
and defrost/floor mode for rapid cool
down of the interior. See ªFast
Cooldownº later in this section.
Mode Control
The mode control allows you to
choose from several patterns of air
distribution.
UNDERSTANDING YOUR INSTRUMENT PANEL 265
4

Window Fogging
Windows will fog on the inside when the humidity inside
the vehicle is high. This often occurs in mild or cool
temperatures when it's rainy or humid. In most cases
turning on the air conditioning (pressing the snowflake
button) will clear the fog. Adjust the temperature control,
air direction and blower speed to maintain comfort.
As the temperature gets colder it may be necessary to
direct air onto the windshield by using MIX Mode
position on the control. Adjust the temperature control
and blower speed to maintain comfort. Higher blower
speeds will reduce fogging. Interior fogging on the
windshield can be quickly removed by selecting the
defrost mode.
Regular cleaning of the inside of the windows with a
non-filming cleaning solution (vinegar and water works
very well) will help prevent contaminates (cigarettesmoke, perfumes, etc.) from sticking to the windows.
Contaminates increase the rate of window fogging.
Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. For proper coolant type,
refer to ªRecommended Fluids and Genuine Partsº in
Section 7.
When using the air conditioner in extremely heavy traffic
in hot weather, especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
NEUTRAL and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.
UNDERSTANDING YOUR INSTRUMENT PANEL 269
4

NTransfer Case Reminder Light............298
NElectronically Shifted Transfer Case Operating
Information/Precautions (5 Position Switch) Ð
If Equipped.........................298
NShifting Procedure Ð Electronically Shifted
Transfer Case........................304
NElectronically Shifted Transfer Case Operating
Information/Precautions (4 Position Switch) Ð
If Equipped.........................306
NShifting Procedure Ð Electronically Shifted
Transfer Case........................311
mLimited-Slip Differential ± If Equipped........313
mDriving On Slippery Surfaces..............314
mDriving Through Water..................315
NFlowing/Rising Water..................315mDriving Off-Road.......................317
mParking Brake.........................318
mBrake System..........................319
N3500 Dual Rear Wheel Models Only........320
NBrake Noise.........................320
NRear Wheel Anti-Lock (RWAL) Brake System Ð
If Equipped.........................320
NFour-Wheel Anti-Lock Brake System Ð
If Equipped.........................321
mPower Steering........................323
mElectronic Brake Control System
(ABS/TCS/BAS/HSA/ERM/ESP/TSC) Ð
If Equipped...........................324
NABS (Anti-Lock Brake System)............325
274 STARTING AND OPERATING

NTraction Control System (TCS)............326
NBAS (Brake Assist System)...............326
NHSA (Hill Start Assist)..................328
NElectronic Roll Mitigation (ERM)..........332
NESP (Electronic Stability Program).........333
NTSC (Trailer Sway Control)..............337
mMulti-Displacement System (MDS) Ð
5.7L Engine Only.......................338
mTire Safety Information...................339
NTire Markings........................339
NTire Loading And Tire Pressure...........343
mTires Ð General Information...............347
NTire Pressure.........................347mSupplemental Tire Pressure Information Ð
If Equipped...........................357
mTire Chains...........................357
mSnow Tires...........................359
mTire Rotation Recommendations............359
NDual Rear Wheels.....................361
mTire Pressure Monitor System (TPMS) Ð
If Equipped...........................362
NTire Pressure Monitor System (TPMS) ªLight
Loadº Reset Switch Description ±
If Equipped.........................365
NTire Pressure Monitor System Components . . . 368
NGeneral Information...................371
STARTING AND OPERATING 275
5

NTowing Tips.........................398
NTrailer Towing Mirrors Ð If Equipped......400
mSnowplow............................401
N1500 Models (Light Duty)...............401
NBefore Plowing.......................403
NSnowplow Model Prep Package Availability . . 403
NOver The Road Operation With Snowplow
Attached...........................404
NMethods For Removing Snow............404NOperating Tips.......................404
NGeneral Maintenance...................405
mRecreational Towing (Behind Motorhome, Etc.) . . 406
NRecreational Towing ±
2-Wheel Drive Models..................406
NRecreational Towing ±
4-Wheel Drive Models..................406
mEquipment Identification Plate.............413
STARTING AND OPERATING 277
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²the engine coolant has reached normal operating tem-
perature;
²vehicle speed is above approximately 30 mph (48
km/h);
²the ªTOW HAUL O/D OFFº switch has not been
activated;
²transmission has reached normal operating tempera-
ture.
NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable level. Refer also to the Note under
torque converter clutch, later in this section.If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough the TRANS TEMP light
may illuminate and the transmission may downshift out
of Overdrive until the transmission cools down. After
cooldown, the transmission will resume normal opera-
tion.
The transmission will downshift from Overdrive to Drive
if the accelerator pedal is fully depressed at vehicle
speeds above approximately 35 mph (56 km/h).
286 STARTING AND OPERATING

When To Use ªTOW HAULº and ªO/D OFFº
Modes
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the ªTOW HAUL O/D OFFº button once to
select TOW HAUL. This will improve performance andreduce the potential for transmission overheating or
failure due to excessive shifting. When operating in
ªTOW HAULº 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 are performed (for im-
proved braking) when driving conditions warrant. Press-
ing the ªTOW HAUL O/D OFFº button a second time to
select O/D OFF will disable 4th and 5th gear completely,
which should eliminate any excessive transmission shift-
ing.
The ªTOW HAULº or ªO/D OFFº 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 ªTOW HAULº or ªO/D OFFº
modes are desired, the button must be pressed each time
the engine is started.
Tow Haul O/D Off Switch
STARTING AND OPERATING 287
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