Overdrive Operation
The automatic transmission includes an electronically con-
trolled Overdrive (fourth and fifth 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 (antifreeze) has reached an adequate
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 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
5
STARTING AND OPERATING 403
WARNING!
Do not use the “TOW/HAUL” feature when driving in
icy or slippery conditions. The increased engine brak-
ing can cause the rear wheels to slide, and the vehicle
to swing around with the possible loss of vehicle
control, which may cause an accident possibly result-
ing in personal injury or death.
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 automatically
at calibrated speeds. This may result in a slightly different
feeling or response during normal operation in 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 sixth gear, until the
transmission fluid and engine coolant are warm [usually
after 1 to 3 miles (2 to 5 km) of driving]. Because sixth
gear is disabled, and the engine speed is higher when
the torque converter clutch is not engaged, it may seem
as if the transmission is not shifting properly 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 transmis-
sion 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 not
cause damage to the transmission. The torque converter
will refill within five seconds after starting the engine.
404 STARTING AND OPERATING
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
WARNING!
Do not use the “TOW/HAUL” feature when driving in
icy or slippery conditions. The increased engine brak-
ing can cause the rear wheels to slide, and the vehicle
to swing around with the possible loss of vehicle
control, which may cause an accident possibly result-
ing in personal injury or death.
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 automatically
at calibrated speeds. This may result in a slightly different
feeling or response during normal operation in 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 to sixth gear, until the trans-
mission fluid and engine coolant are warm [usually after
1 to 3 miles (2 to 5 km) of driving]. Because sixth gear is
disabled, and engine speed is higher when the torque
converter clutch is not engaged, it may seem as if the
transmission is not shifting properly 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 transmis-
sion 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 not
cause damage to the transmission. The torque converter
will refill within five seconds after starting the engine.
5
STARTING AND OPERATING 413
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
Recreational Towing — Two-Wheel Drive Models
DO NOT flat tow this vehicle. Damage to the drivetrain
will result.
Recreational towing (for two-wheel drive models) is al-
lowedONLY if the rear wheels are OFFthe ground. This
may be accomplished using a tow dolly or vehicle trailer. If
using a tow dolly, follow this procedure:
NOTE: If vehicle is equipped with air suspension, ensure
the vehicle is set to Normal Ride Height.
1. Properly secure the dolly to the tow vehicle, following the dolly manufacturer’s instructions.
2. Drive the rear wheels onto the tow dolly.
3. Firmly apply the parking brake. Place automatic trans- mission in PARK, manual transmission in gear (not in
NEUTRAL).
4. Properly secure the rear wheels to the dolly, following the dolly manufacturer’s instructions.
5. Turn the ignition OFF and remove the key fob.
6. Install a suitable clamping device, designed for towing, to secure the front wheels in the straight position.
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 recreational
towing. Refer to the following for the proper transfer case
NEUTRAL (N) shifting procedure for your vehicle.
5
STARTING AND OPERATING 573
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).
• Tow only in the forward direction. Towing this
vehicle backwards can cause severe damage to the
transfer case.
• Before recreational towing, the transfer case must be
in NEUTRAL. To be certain the transfer case is fully
in NEUTRAL, perform the procedure outlined under
“Shifting Into NEUTRAL”. Internal transmission
damage will result, if the transfer case is not in
NEUTRAL during towing.
• Automatic transmissions must be placed in PARK,
and manual transmissions must be placed in gear
(not in Neutral) for recreational towing.
• Towing this vehicle in violation of the above require-
ments can cause severe transmission and/or transfer
case damage. Damage from improper towing 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 NEU-
TRAL (N) position without first fully engaging the
parking brake. The transfer case NEUTRAL (N) posi-
tion disengages both the front and rear drive shaft
from the powertrain, and will allow the vehicle to roll,
even if the automatic transmission is in PARK (or
manual transmission is in gear). The parking brake
should always be applied when the driver is not in the
vehicle.
574 STARTING AND OPERATING
MAINTAINING YOUR VEHICLE
CONTENTS
ENGINE COMPARTMENT — 3.6L ...........633
ENGINE COMPARTMENT — 5.7L ...........634
ENGINE COMPARTMENT — 6.4L ...........635
ONBOARD DIAGNOSTIC SYSTEM (OBD II) . . . .636
▫ Onboard Diagnostic System (OBD II)
Cybersecurity ........................ .636
▫ Loose Fuel Filler Cap Message .............637
EMISSIONS INSPECTION AND
MAINTENANCE PROGRAMS ..............637
REPLACEMENT PARTS ...................639
DEALER SERVICE ...................... .639
MAINTENANCE PROCEDURES .............639
▫ Engine Oil .......................... .640
▫ Engine Oil Filter ...................... .642
▫ Engine Air Cleaner Filter .................643 ▫
Accessory Drive Belt Inspection ............646
▫ Maintenance-Free Battery .................648
▫ Air Conditioner Maintenance ..............649
▫ Front Driveshaft Lubrication — 2500/3500
(Four-Wheel Drive Models Only) ............655
▫ Body Lubrication ..................... .656
▫ Windshield Wiper Blades .................656
▫ Adding Washer Fluid ...................659
▫ Exhaust System ....................... .660
▫ Cooling System ....................... .662
▫ Brake System ........................ .667
▫ Rear Axle And 4x4 Front Driving
Axle Fluid Level ...................... .668
▫ Transfer Case ........................ .669
▫ Automatic
Transmission ..................669
7