brake JEEP COMMANDER 2010 1.G Service Manual

period of time after the driver takes their foot off of the
brake pedal. If the driver does not apply the throttle
during this short period of time, the system will release
brake pressure and the vehicle will roll down the hill. The
system will release brake pressure in proportion to the
amount of throttle applied as the vehicle starts to move in
the intended direction of travel.
HSA Activation Criteria
The following criteria must be met in order for HSA to
activate:
•Vehicle must be stopped.
•Vehicle must be on a 8% grade or greater hill.
•Gear selection matches vehicle uphill direction (i.e.,
vehicle facing uphill is in forward gear; vehicle back-
ing uphill is in REVERSE gear).HSA will work in REVERSE and all forward gears when
the activation criteria have been met. The system will not
activate if the vehicle is placed in NEUTRAL or PARK.
WARNING!
There may be situations on minor hills (i.e., less than
8%), with a loaded vehicle, or while pulling a trailer,
when the system will not activate and slight rolling
may occur. This could cause a collision with another
vehicle or object. Always remember the driver is
responsible for braking the vehicle.
Towing with HSA
HSA will provide assistance when starting on a grade
when pulling a trailer.
5
STARTING AND OPERATING 281

WARNING!
•If you use a trailer brake controller with your
trailer, your trailer brakes may be activated and
deactivated with the brake switch. If so, when the
brake pedal is released, there may not be enough
brake pressure to hold the vehicle and trailer on a
hill and this could cause a collision with another
vehicle or object behind you. In order to avoid
rolling down the hill while resuming acceleration,
manually activate the trailer brake prior to releas-
ing the brake pedal. Always remember the driver
is responsible for braking the vehicle.(Continued)
WARNING! (Continued)
•HSA is not a parking brake. If you stop the vehicle
on a hill without putting the transmission in
PARK and using the parking brake, it will roll
down the hill and could cause a collision with
another vehicle or object. Always remember to use
the parking brake while parking on a hill, and that
the driver is responsible for braking the vehicle.
HSA Off
If you wish to turn off the HSA system, it can be done
using the Customer Programmable Features in the Elec-
tronic Vehicle Information Center (EVIC). Refer to “Elec-
tronic Vehicle Information Center (EVIC)” in Section 4 of
this manual.
282 STARTING AND OPERATING

Hill Descent Control (HDC) – Four-Wheel Drive
Models With NV245 Two–Speed Transfer Case
Only
HDC maintains vehicle speed while descending hills
during off-road driving situations and is available in
4WD LOW range only. To enable HDC (transfer case
must be in 4WD LOW range), press the HDC switch. If
the HDC switch is pressed when the vehicle is not in
4WD LOW range, the light in the switch will flash for five
seconds and HDC will not be enabled.When HDC is properly enabled, the message “HILL
DESCENT CONTROL” will appear in the EVIC and the
light in the switch will be illuminated. HDC will auto-
matically apply the brakes to control downhill speed
when necessary. HDC has the capability to sense terrain
Hill Descent Switch
5
STARTING AND OPERATING 283

and will only activate when the vehicle is descending a
hill. 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.
•1st = 1 mph (1.6 km/h)
•2nd = 2.5 mph (4 km/h)
•3rd = 4 mph (6 km/h)
•4th = 5.5 mph (9 km/h)
•5th = 7.5 mph (12 km/h)
•REVERSE = 1 mph (1.6 km/h)
•NEUTRAL = 2.5 mph (4 km/h)
•PARK = HDC will not functionHDC also has the capability to sense rough terrain, and
will automatically adjust to a slightly slower set speed
[about 0.3 mph (0.5 km/h) than normal.]
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 is intended for low speed off-road driving only.
At vehicle speeds above 30 mph (48 km/h), HDC will no
longer function. When the vehicle speed drops below
30 mph (48 km/h), HDC function will automatically
resume and the vehicle speed will return to the chosen set
speed.
284 STARTING AND OPERATING

Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb weight
values are determined by weighing your vehicle on a
commercial scale before any occupants or cargo are
added.
Loading
The actual total weight and the weight of the front and
rear of your vehicle at the ground can best be determined
by weighing it when it is loaded and ready for operation.
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 vehicleshould 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.
322 STARTING AND OPERATING

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 manufacturer’s 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
trailer stability. Trailer sway control and a weight distrib-
uting (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 an accident.
•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.
5
STARTING AND OPERATING 325

•When hauling cargo or towing a trailer, do not over-
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to brakes,
axle, engine, transmission, steering, suspension, chas-
sis 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.
•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).
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 this section.
5
STARTING AND OPERATING 331

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 Infor-
mation” in this section.
When replacing tires, refer to “Tires–General Informa-
tion” in this section. 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).
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.
332 STARTING AND OPERATING

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 an
accident.
•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 an accident.
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.
The electrical connections are all complete to the vehicle
but you must mate the harness to a trailer connector.
Refer to the following illustrations.
5
STARTING AND OPERATING 333

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
334 STARTING AND OPERATING