gear range will improve performance and extend transmis-
sion life by reducing excessive shifting and heat buildup.
If the transmission temperature exceeds normal operating
limits, the powertrain controller will modify the transmis-
sion shift schedule and expand the range of torque con-
verter clutch engagement. This is done to prevent trans-
mission damage due to overheating.
If the transmission becomes extremely hot or is in danger
of overheating, the “Transmission Temperature Warning
Light” may illuminate and the transmission may operate
differently until the transmission cools down.
NOTE:Use caution when operating a heavily loaded
vehicle at low speeds (such as towing a trailer up a steep
grade, or in stop-and-go traffic) during hot weather. In
these conditions, torque converter slip can impose a sig-
nificant additional heat load on the cooling system. Down-
shifting the transmission to the lowest possible gear (when
climbing a grade), or shifting to NEUTRAL (when stopped
in heavy traffic) can help to reduce this excess heat
generation. During cold temperatures, transmission operation may be
modified depending on engine and transmission tempera-
ture as well as vehicle speed. This feature improves warm
up time of the engine and transmission to achieve maxi-
mum efficiency. Engagement of both the torque converter
clutch and the top overdrive gear are inhibited until the
transmission fluid is warm (refer to the “Note” under
“Torque Converter Clutch” in this section). During ex-
tremely cold temperatures (-16°F [-27°C] or below), opera-
tion may briefly be limited to first and direct gears only.
Normal operation will resume once the transmission tem-
perature has risen to a suitable level.
Transmission Limp Home Mode
Transmission function is monitored electronically for ab-
normal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in fourth gear regardless of which forward gear is selected.
PARK, REVERSE, and NEUTRAL will continue to operate.
The Malfunction Indicator Light (MIL) may be illuminated.
Limp Home Mode allows the vehicle to be driven to an
authorized dealer for service without damaging the trans-
mission.
5
STARTING AND OPERATING 409
Overdrive Operation
The automatic transmission includes an electronically con-
trolled Overdrive (fifth and sixth gears). The transmission
will automatically shift into Overdrive if the following
conditions are present:
•The gear selector is in the DRIVE position.
• The transmission fluid has reached an adequate tem-
perature.
• The engine coolant has reached an adequate tempera-
ture.
• Vehicle speed is sufficiently high.
• The TOW/HAUL switch has not been activated.
• The driver is not heavily pressing the accelerator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting occurs,
push the TOW/HAUL switch to activate TOW/HAUL
mode. This will improve performance and reduce the
potential for transmission overheating or failure due to
excessive shifting. When operating in TOW/HAUL mode,
transmission upshifts are delayed, and the transmission will automatically downshift (for engine braking) when the
throttle is closed and/or during steady braking maneu-
vers.
The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode has
been activated. Pushing the switch a second time restores
normal operation. Normal operation is always the default
at engine start-up. If TOW/HAUL mode is desired, the
switch must be pushed each time the engine is started.
TOW/HAUL Switch
412 STARTING AND OPERATING
Materials Added To Fuel
Besides using unleaded gasoline with the proper octane
rating, gasolines that contain detergents, corrosion, and
stability additives are recommended. Using gasolines that
have these additives will help improve fuel economy,
reduce emissions, and maintain vehicle performance.Designated TOP TIER Detergent Gaso-
line contains a higher level of detergents
to further aide in minimizing engine
and fuel system deposits. When avail-
able, the usage of Top Tier Detergent
gasoline is recommended. Visit
www.toptiergas.com for a list of TOP
TIER Detergent Gasoline Retailers.
Indiscriminate use of fuel system cleaning agents should be
avoided. Many of these materials intended for gum and
varnish removal may contain active solvents or similar
ingredients. These can harm fuel system gasket and dia-
phragm materials.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
• The use of leaded gasoline is prohibited by Federal
law. Using leaded gasoline can impair engine perfor-
mance and damage the emissions control system.
• An out-of-tune engine or certain fuel or ignition
malfunctions can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your authorized dealer for service assistance.
• The use of fuel additives, which are now being sold
as octane enhancers, is not recommended. Most of
these products contain high concentrations of metha-
nol. Fuel system damage or vehicle performance
problems resulting from the use of such fuels or
additives is not the responsibility of the manufac-
turer and may void or not be covered under the New
Vehicle Limited Warranty.
544 STARTING AND OPERATING
Towing Tips
Before setting out on a trip, practice turning, stopping and
backing the trailer up in an area away from heavy traffic.
Automatic Transmission
The DRIVE range can be selected when towing. The
transmission controls include a drive strategy to avoid
frequent shifting when towing. However, if frequent shift-
ing does occur while in DRIVE, select TOW/HAUL mode
or select a lower gear range (using the Electronic Range
Select (ERS) shift control).
NOTE:Using TOW/HAUL mode or selecting a lower
gear range (using the ERS shift control) while operating the
vehicle under heavy loading conditions will improve per-
formance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
When towing a loaded trailer up steep grades at low
speeds (20 mph [32 km/h] or below), holding your vehicle
in first gear (using the ERS shift control) can help to avoid
transmission overheating. If you regularly tow a trailer for more than 45 minutes of
continuous operation, then change the automatic transmis-
sion fluid and filter(s) as specified for
police, taxi, fleet, or
frequent trailer towing. Refer to the “Maintenance Sched-
ule” for the proper maintenance intervals.
NOTE: Check the automatic transmission fluid level be-
fore towing (6-speed automatic only).
Tow/Haul Mode
To reduce potential for automatic transmission overheat-
ing, activate TOW/HAUL mode when driving in hilly
areas, or select a lower gear range (using the Electronic
Range Select (ERS) shift control) on more severe grades.
Electronic Speed Control — If Equipped
• Do not 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.
5
STARTING AND OPERATING 567
Cooling System
To reduce potential for engine and transmission overheat-
ing, take the following actions:
City Driving
When stopped for short periods of time, shift the transmis-
sion into NEUTRAL and increase engine idle speed.
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
Air Suspension System
To aid in attaching/detaching the trailer from the vehicle,
the air suspension system can be used. Refer to “Air
Suspension System” in “Starting And Operating” for fur-
ther information.
NOTE:The vehicle must remain in the engine running
position while attaching a trailer for proper leveling of the
air suspension system.
SNOWPLOW
1500 Models Only
NOTE: Do not use this model vehicle for snowplow
applications.
WARNING!
Snowplows and other aftermarket equipment should
not be added to the front end of your vehicle. The
airbag crash sensors may be affected by the change in
the front end structure. The airbags could deploy
unexpectedly or could fail to deploy during a collision
resulting in serious injury or death.
CAUTION!
Using this vehicle for snowplow applications can
cause damage to the vehicle.
568 STARTING AND OPERATING
Operating Tips
Under ideal snow plowing conditions, 20 mph (32 km/h)
should be maximum operating speed. The operator should
be familiar with the area and surface to be cleaned. Reduce
speed and use extreme caution when plowing unfamiliar
areas or under poor visibility.
General Maintenance
Snowplows should be maintained in accordance with the
plow manufacturer’s instructions.
Keep all snowplow electrical connections and battery ter-
minals clean and free of corrosion.When plowing snow, to avoid transmission and drivetrain
damage, the following precautions should be observed.
•
Operate with transfer case in 4LO when plowing small
or congested areas where speeds are not likely to exceed
15 mph (24 km/h). At higher speeds operate in 4HI.
• Vehicles with automatic transmissions should use 4LO
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 while shifting the
transmission.
5
STARTING AND OPERATING 571
WHAT TO DO IN EMERGENCIES
CONTENTS
HAZARD WARNING FLASHERS ............580
IF YOUR ENGINE OVERHEATS .............580
WHEEL AND TIRE TORQUE
SPECIFICATIONS ...................... .581
▫ Torque Specifications ....................581
JACKING AND TIRE CHANGING ............583
▫ Jacking And Tire Changing
1500 Series Trucks ..................... .583
▫ Jacking And Tire Changing
2500 And 3500 Series Trucks ...............600
HOISTING ........................... .618
JUMP-STARTING PROCEDURES ............618
▫ Preparations For Jump-Start ...............618
▫ Jump-Starting Procedure ..................620
FREEING A STUCK VEHICLE ..............621
EMERGENCY TOW HOOKS — IF EQUIPPED . . . .623
GEAR SELECTOR OVERRIDE — 6-SPEED
TRANSMISSION ....................... .623
▫ Column Shifter — If Equipped .............623
▫ Center Console Shifter — If Equipped ........624
MANUAL PARK RELEASE — 8 SPEED
TRANSMISSION ....................... .625
TOWING A DISABLED VEHICLE ............626
▫ Two-Wheel Drive Models .................628
▫ Four-Wheel Drive Models .................629
ENHANCED ACCIDENT RESPONSE SYSTEM
(EARS) .............................. .630
EVENT DATA RECORDER (EDR) ............630
6
HAZARD WARNING FLASHERS
The Hazard Warning flasher switch is located on the upper
switch bank just below the radio.Push the switch to turn on the Hazard Warning
flasher. When the switch is activated, all directional
turn signals will flash on and off to warn oncoming traffic
of an emergency. Push the switch a second time to turn off
the Hazard Warning flashers.
This is an emergency warning system and it should not be
used when the vehicle is in motion. Use it when your
vehicle is disabled and it is creating a safety hazard for
other motorists.
When you must leave the vehicle to seek assistance, the
Hazard Warning flashers will continue to operate even
though the ignition is placed in the OFF position.
NOTE: With extended use the Hazard Warning flashers
may wear down your battery.
IF YOUR ENGINE OVERHEATS
In any of the following situations, you can reduce the
potential for overheating by taking the appropriate action.
• On the highways — slow down.
• In city traffic — while stopped, place the transmission in
NEUTRAL, but do not increase the engine idle speed
while preventing vehicle motion with the brakes.
NOTE: There are steps that you can take to slow down an
impending overheat condition:
• If your air conditioner (A/C) is on, turn it off. The A/C
system adds heat to the engine cooling system and
turning the A/C off can help remove this heat.
• You can also turn the temperature control to maximum
heat, the mode control to floor and the blower control to
high. This allows the heater core to act as a supplement
to the radiator and aids in removing heat from the
engine cooling system.
580 WHAT TO DO IN EMERGENCIES