CAUTION!
When using ERS for engine braking while descend-
ing steep grades, be careful not to overspeed the
engine. Apply the brakes as needed to prevent en-
gine overspeed.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fourth and fifth gears). The trans-
mission will automatically shift into Overdrive if the
following conditions are present:
•the shift lever is in the DRIVE position,
•the transmission fluid has reached an adequate tem-
perature,
•the engine coolant (antifreeze) has reached an ad-
equate temperature,
•vehicle speed is sufficiently high,•the TOW/HAUL switch has not been activated, and
•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 oc-
curs, 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 trans-
mission will automatically downshift (for engine brak-
ing) when the throttle is closed and/or during steady
braking maneuvers.
5
STARTING AND OPERATING 509
the upper gears. When the vehicle speed drops or during
some accelerations, the clutch automatically disengages.
NOTE:
•The torque converter clutch will not engage, and the
transmission will not shift into the top overdrive gear,
until the transmission fluid and engine coolant are
warm [usually after 1 to 3 miles (2 to 5 km) of driving].
Because top gear is disabled, and the engine speed is
higher when the torque converter clutch is not en-
gaged, it may seem as if the transmission is not shifting
properly when cold. This is normal. Using the Elec-
tronic Range Select (ERS) shift control, when the
transmission is sufficiently warm, will demonstrate
that the transmission is able to shift into and out of
Overdrive.
•If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the trans-
mission into gear may seem sluggish. This is due to thefluid partially draining from the torque converter into
the transmission. This condition is normal and will not
cause damage to the transmission. The torque con-
verter will refill within five seconds after starting the
engine.
Six-Speed Automatic Transmission — 2500/3500
Models Only
The transmission gear position display (located in the
instrument cluster) indicates the transmission gear range.
The shift lever is mounted on the right side of the steering
column. You must press the brake pedal to move the shift
lever out of PARK (refer to “Brake/Transmission Shift
Interlock System” in this section for further information).
To drive, move the shift lever from PARK or NEUTRAL
to the DRIVE position. Pull the shift lever toward you
when shifting into REVERSE or PARK, or when shifting
out of PARK.5
STARTING AND OPERATING 511
CAUTION!
When using ERS for engine braking while descend-
ing steep grades, be careful not to overspeed the
engine. Apply the brakes as needed to prevent en-
gine overspeed.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fifth and sixth gears). The trans-
mission will automatically shift into Overdrive if the
following conditions are present:
•The shift lever 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 oc-
curs, 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 trans-
mission will automatically downshift (for engine brak-
ing) during steady braking maneuvers.
520 STARTING AND OPERATING
the upper gears. When the vehicle speed drops or during
some accelerations, the clutch automatically disengages.
NOTE:
•The torque converter clutch will not engage, until the
transmission fluid and engine coolant are warm [usu-
ally after 1 to 3 miles (2 to 5 km) of driving]. Because
the engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmis-
sion is not shifting into Overdrive when cold. This is
normal. Using the Electronic Range Select (ERS) shift
control, when the transmission is sufficiently warm,
will demonstrate that the transmission is able to shift
into and out of Overdrive.
•If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the trans-
mission into gear may seem sluggish. This is due to the
fluid partially draining from the torque converter into
the transmission. This condition is normal and will notcause damage to the transmission. The torque con-
verter will refill within five seconds after starting the
engine.
FOUR-WHEEL DRIVE OPERATION — IF
EQUIPPED
Four-wheel drive trucks are equipped with either a manu-
ally shifted transfer case or an electronically shifted transfer
case. Refer to the operating instructions for your transfer
case, located in this section for further information.
Manually Shifted Transfer Case — If Equipped
The transfer case provides four mode positions:
•Two-wheel drive high range (2H)
•Four-wheel drive high range (4H)
•Neutral (N)
•Four-wheel drive low range (4L)
522 STARTING AND OPERATING
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 trans-
mission fluid and filter(s) as specified forpolice, taxi,
fleet, or frequent trailer towing.Refer to the “Mainte-
nance Schedule” for the proper maintenance intervals.
NOTE:Check the automatic transmission fluid level
before 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.
Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
City Driving
When stopped for short periods of time, shift the trans-
mission into NEUTRAL and increase engine idle speed.
Highway Driving
Reduce speed.
5
STARTING AND OPERATING 709
CAUTION!
•Towing with the rear wheels on the ground will
cause severe transmission damage. Damage from
improper towing is not covered under the New
Vehicle Limited Warranty.
•Do not disconnect the driveshaft because fluid may
leak from the transmission, causing damage to
internal parts.
Recreational Towing — Four-Wheel Drive Models
NOTE:Both the manual shift and electronic shift transfer
cases must be shifted into NEUTRAL (N) for recreational
towing. Automatic transmissions must be shifted into
PARK for recreational towing. Manual transmissions
must be placed in gear (NOT in NEUTRAL) for recre-
ational towing. Refer to the following for the proper
transfer case NEUTRAL (N) shifting procedure for your
vehicle.
CAUTION!
•DO NOT dolly tow any 4WD vehicle. Towing with
only one set of wheels on the ground (front or rear)
will cause severe transmission and/or transfer case
damage. Tow with all four wheels either ON the
ground, or OFF the ground (using a vehicle trailer).
(Continued)
716 STARTING AND OPERATING
CAUTION!(Continued)
•Tow only in the forward direction. Towing this
vehicle backwards can cause severe damage to the
transfer case.
•Automatic transmissions must be placed in PARK
for recreational towing.
•Manual transmissions must be placed in gear (not
in Neutral) for recreational towing.
•Before recreational towing, perform the procedure
outlined under “Shifting Into NEUTRAL (N)” to be
certain that the transfer case is fully in NEUTRAL
(N). Otherwise, internal damage will result.
•Towing this vehicle in violation of the above re-
quirements can cause severe transmission and/or
transfer case damage. Damage from improper tow-
ing is not covered under the New Vehicle Limited
Warranty.
(Continued)
CAUTION!(Continued)
•Do not disconnect the rear driveshaft because fluid
will leak from the transfer case, causing damage to
internal parts.
•Do not use a bumper-mounted clamp-on tow bar
on your vehicle. The bumper face bar will be
damaged.
Shifting Into NEUTRAL (N)
Use the following procedure to prepare your vehicle for
recreational towing.
WARNING!
You or others could be injured or killed if you leave
the vehicle unattended with the transfer case in the
NEUTRAL (N) position without first fully engaging
(Continued)
5
STARTING AND OPERATING 717
▫Adding Washer Fluid..................811
▫Exhaust System......................812
▫Cooling System......................815
▫Brake System........................823
▫Rear Axle And 4x4 Front Driving Axle Fluid
Level..............................825
▫Transfer Case........................826
▫Automatic Transmission................826
▫Appearance Care And Protection From
Corrosion...........................830
FUSES..............................838
▫Power Distribution Center...............839
VEHICLE STORAGE....................848REPLACEMENT BULBS.................849
BULB REPLACEMENT..................850
▫Base Quad / Premium Bi-Halogen: Low Beam
Headlamp, High Beam Headlamp, Front Park
And Turn — If Equipped...............851
▫Fog Lamps — If Equipped..............853
▫Rear Tail/Stop, Turn Signal And Backup Lamps
..................................853
▫Center High-Mounted Stoplamp (CHMSL) With
Cargo Lamp.........................855
▫Cab Top Clearance Lamps — If Equipped. . . .857
▫Rear Lamp Bar ID Marker (Dual Rear Wheels) —
If Equipped..........................859
▫Side Marker Lamps (Dual Rear Wheels) — If
Equipped...........................860
786 MAINTAINING YOUR VEHICLE