brake JEEP COMMANDER 2009 1.G Service Manual

WARNING!
With the ESP switched off, the enhanced vehicle
stability offered by ESP and ERM are unavailable. In
an emergency evasive maneuver, the ESP and ERM
systems will not engage to assist in maintaining
stability. The “Full Off” mode is intended for off-
road use only.
TSC (Trailer Sway Control)
TSC uses sensors in the vehicle to recognize an exces-
sively swaying trailer and will take the appropriate
actions to attempt to stop the sway. The system may
reduce engine power and apply the brake of the appro-
priate wheel(s) to counteract the sway of the trailer. TSC
will become active automatically once an excessively
swaying trailer is recognized. No driver action is re-
quired. Note that TSC cannot stop all trailers fromswaying. Always use caution when towing a trailer and
follow the trailer tongue weight recommendations. Refer
to “Trailer Towing” in Section 5 of this manual. When
TSC is functioning, the ESP/TCS Indicator Light will
flash, the engine power may be reduced and you may
feel the brakes being applied to individual wheels to
attempt to stop the trailer from swaying. TSC is disabled
when the ESP system is in the “Partial Off” or “Full Off”
modes.WARNING!
If TSC activates while driving, slow the vehicle
down, stop at the nearest safe location, and adjust the
trailer load to eliminate trailer sway.
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HSA (Hill Start Assist) (4WD Models With NV245
Two–Speed Transfer Case Only)
The HSA system is designed to assist the driver when
starting a vehicle from a stop on a hill. HSA will maintain
the level of brake pressure the driver applied for a short
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
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.
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Towing with HSA
HSA will provide assistance when starting on a grade
when pulling a trailer.
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.
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HDC (Hill Descent Control) (4WD 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
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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.
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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 re-
view 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.
Common Towing Definitions
The following trailer towing related definitions will assist
you in understanding the following information:
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total allowable weight of your vehicle.
This includes driver, passengers, cargo and trailer tongue
weight. The total load must be limited so that you do not
exceed the GVWR.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus the weight of all
cargo, consumables and equipment (permanent or tem-
porary) loaded in or on the trailer in itsloaded and
ready for operationcondition. The recommended way to
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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 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 andtrailer 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 braking
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 additional information.
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•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).
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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.
Also, check the trailer tires for proper tire inflation
pressures 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

Donotinterconnect 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).
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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 hy-
draulic brake lines. It can overload your brake sys-
tem 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 dis-
tance. When towing, you should allow for additional
space between your vehicle and the vehicle in front
of you. Failure to do so could result in an accident.
Towing Requirements — Trailer Lights & 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 may include a 4 and 7–pin
wiring harness. Use a factory approved trailer harness
and connector.
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