2011 JEEP GRAND CHEROKEE brake

When HDC is enabled, the HDC icon will be illuminated
in the instrument cluster. HDC will automatically apply
the brakes to control downhill speed to the selected level
when necessary on grades greater than approximately
8%. It will usually not activate on level ground.The HDC speed may be adjusted by the driver to suit the
driving conditions. The speed corresponds to the trans-
mission gear selected.
HDC operation can be overridden with brake application
to slow the vehicle down below the HDC control speed.
Conversely, if more speed is desired during HDC control,
the accelerator pedal will increase vehicle speed in the
usual manner. When either the brake or the accelerator is
released, HDC will control the vehicle back to the origi-
nal set speed.
HDC Operation in 4WD Low Range
To enable HDC, press the HDC switch or put the
Selec-Terrain™ system in the “ROCK” mode. The HDC
icon will be illuminated in the instrument cluster and
HDC will function. If the vehicle speed goes above
20 mph (32 km/h), the HDC icon will flash and HDC will
not function. To disable HDC, press the HDC switch.Hill Descent Switch
5
STARTING AND OPERATING 391

The entire vehicle should first be weighed on a commer-
cial scale to ensure that the GVWR has not been ex-
ceeded. The weight on the front and rear of the vehicle
should then be determined separately to be sure that the
load is properly distributed over front and rear axle.
Weighing the vehicle may show that the GAWR of either
the front or rear axles has been exceeded, but the total
load is within the specified GVWR. If so, weight must be
shifted from front to rear, or rear to front, as appropriate
until the specified weight limitations are met. Store the
heavier items down low and be sure that the weight is
distributed equally. Stow all loose items securely before
driving.
Improper weight distributions can have an adverse affect
on the way your vehicle steers and handles, and the way
the brakes operate.CAUTION!
Do not load your vehicle any heavier than the GVWR
or the maximum front and rear GAWR. If you do,
parts on your vehicle can break, or it can change the
way your vehicle handles. This could cause you to
lose control. Also, overloading can shorten the life of
your vehicle.
TRAILER TOWING
In this section you will find safety tips and information
on limits to the type of towing you can reasonably do
with your vehicle. Before towing a trailer, carefully
review this information to tow your load as efficiently
and safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this manual concerning ve-
hicles used for trailer towing.
438 STARTING AND OPERATING

rear GAWR. Refer to “Vehicle Loading/Vehicle Certifica-
tion Label” in “Starting and Operating” for further
information.
WARNING!
It is important that you do not exceed the maximum
front or rear GAWR. A dangerous driving condition
can result if either rating is exceeded. You could lose
control of the vehicle and have a collision.
Trailer Tongue Weight (TW)
The TW is the downward force exerted on the hitch ball
by the trailer. In most cases it should not be less than 10%
or more than 15% of the trailer load. You must consider
this as part of the load on your vehicle.
Frontal Area
The frontal area is the maximum height multiplied by the
maximum width of the front of a trailer.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer tongue
weight, just as if it were luggage located at a hitch ball or
some other connecting point of the vehicle. These kind of
hitches are the most popular on the market today and
they are commonly used to tow small- and medium-
sized trailers.
Weight-Distributing Hitch
A weight-distributing hitch system works by applying
leverage through spring (load) bars. They are typically
used for heavier loads, to distribute trailer tongue weight
to the tow vehicle’s front axle and the trailer axle(s).
When used in accordance with the manufacturers’ direc-
tions, it provides for a more level ride, offering more
consistent steering and brake control, thereby enhancing
towing safety. The addition of a friction/hydraulic sway
control also dampens sway caused by traffic and cross-
winds, and contributes positively to tow vehicle and
440 STARTING AND OPERATING

trailer stability. Trailer sway control and a weight-
distributing (load equalizing) hitch are recommended for
heavier trailer tongue weights (TW) and may be required
depending on Vehicle and Trailer configuration/loading
to comply with gross axle weight rating (GAWR)
requirements.
WARNING!
•An improperly adjusted weight-distributing hitch
system may reduce handling, stability, and brak-
ing performance, and could result in a collision.
•Weight-distributing hitch systems may not be
compatible with Surge Brake Couplers. Consult
with your hitch and trailer manufacturer or a
reputable Recreational Vehicle dealer for addi-
tional information.Without Weight-Distributing Hitch (Incorrect)
5
STARTING AND OPERATING 441

WARNING! (Continued)
•Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have a collision.
•When hauling cargo or towing a trailer, do not
overload your vehicle or trailer. Overloading can
cause a loss of control, poor performance or dam-
age to brakes, axle, engine, transmission, steering,
suspension, chassis structure or tires.
•Safety chains must always be used between your
vehicle and trailer. Always connect the chains to
the hook retainers of the vehicle hitch. Cross the
chains under the trailer tongue and allow enough
slack for turning corners.(Continued)
WARNING! (Continued)
•Vehicles with trailers should not be parked on a
grade. When parking, apply the parking brake on
the tow vehicle. Put the tow vehicle transmission
in PARK. For four-wheel drive vehicles, make sure
the transfer case is not in NEUTRAL. Always,
block orchockthe trailer wheels.
•GCWR must not be exceeded.
•Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
2. GTW
3. GAWR
4. Trailer tongue weight rating for the trailer hitch
utilized (This requirement may limit the ability to
always achieve the 10% to 15% range of tongue
weight as a percentage of total trailer weight).5
STARTING AND OPERATING 447

Towing Requirements – Tires

Do not attempt to tow a trailer while using a compact
spare tire.
Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to
“Tires – General Information” in “Starting and Oper-
ating” for proper tire inflation procedures.
Check the trailer tires for proper tire inflation pres-
sures before trailer usage.
Check for signs of tire wear or visible tire damage
before towing a trailer. Refer to “Tires – General
Information” in “Starting and Operating” for proper
inspection procedure.
When replacing tires, refer to “Tires – General Infor-
mation” in “Starting and Operating” for proper tire replacement procedures. Replacing tires with a higher
load carrying capacity will not increase the vehicle’s
GVWR and GAWR limits.
Towing Requirements – Trailer Brakes

Do
not interconnect the hydraulic brake system or
vacuum system of your vehicle with that of the trailer.
This could cause inadequate braking and possible
personal injury.
An electronically-actuated trailer brake controller is
required when towing a trailer with electronically-
actuated brakes. When towing a trailer equipped with
a hydraulic surge-actuated brake system, an electronic
brake controller is not required.
Trailer brakes are recommended for trailers over
1,000 lbs (454 kg), and required for trailers in excess of
2,000 lbs (907 kg).
448 STARTING AND OPERATING

CAUTION!
If the trailer weighs more than 1,000 lbs (454 kg)
loaded, it should have its own brakes and they
should be of adequate capacity. Failure to do this
could lead to accelerated brake lining wear, higher
brake pedal effort, and longer stopping distances.
WARNING!
•Do not connect trailer brakes to your vehicle’s
hydraulic brake lines. It can overload your brake
system and cause it to fail. You might not have
brakes when you need them and could have a
collision.(Continued)
WARNING! (Continued)
•Towing any trailer will increase your stopping
distance. When towing, you should allow for ad-
ditional space between your vehicle and the ve-
hicle in front of you. Failure to do so could result
in a collision.
Towing Requirements – Trailer Lights and Wiring
Whenever you pull a trailer, regardless of the trailer size,
stop lights and turn signals on the trailer are required for
motoring safety.
The Trailer Tow Package includes a seven–pin connector
at the rear of the vehicle and a four-pin harness located
under the rear bumper. The four-pin harness must be
unclipped before use. Use a factory-approved trailer
harness and connector.5
STARTING AND OPERATING 449

The electrical connections are all complete to the vehicle
but you must mate the harness to a trailer connector.
Refer to the following illustrations.
Four-Pin Connector
1 — Female Pins4 — Park
2 — Male Pin 5 — Left Stop/Turn
3 — Ground 6 — Right Stop/Turn
Seven-Pin Connector
1 — Battery5 — Ground
2 — Backup Lamps 6 — Left Stop/Turn
3 — Right Stop/Turn 7 — Running Lamps
4 — Electric Brakes
450 STARTING AND OPERATING