brakes JEEP COMMANDER 2009 1.G User Guide

benefit of the system, you must applycontinuousbrak-
ing pressure during the stopping sequence (do not
“pump” the brakes). Do not reduce brake pedal pressure
unless braking is no longer desired. Once the brake pedal
is released, the BAS is deactivated.
WARNING!
BAS (Brake Assist System) cannot prevent the natu-
ral laws of physics from acting on the vehicle, nor can
it increase the traction afforded by prevailing road
conditions. BAS cannot prevent accidents, including
those resulting from excessive speed in turns, driving
on very slippery surfaces, or hydroplaning. Only a
safe, attentive, and skillful driver can prevent acci-
dents. The capabilities of a BAS-equipped vehicle
must never be exploited in a reckless or dangerous
manner which could jeopardize the user’s safety or
the safety of others.
ERM (Electronic Roll Mitigation)
This system anticipates the potential for wheel lift by
monitoring the driver ’s steering wheel input and the
speed of the vehicle. When ERM determines that the rate
of change of the steering wheel angle and vehicle speed
are sufficient to potentially cause wheel lift, it then
applies the brake of the appropriate wheel and may also
reduce engine power to lessen the chance that wheel lift
will occur. ERM will only intervene during very severe or
evasive driving maneuvers.
ERM can only reduce the chance of wheel lift occurring
during severe or evasive driving maneuvers. It cannot
prevent wheel lift due to other factors such as road
conditions, leaving the roadway or striking objects or
other vehicles.
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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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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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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
380 STARTING AND OPERATING

•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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The electrical connections are all complete to the vehicle
but you must mate the harness to a trailer connector.
Refer to the following illustrations.
4-Pin Connector
1 — Female Pins 4 — Park
2 — Male Pin 5 — Left Stop/Turn
3 — Ground 6 — Right Stop/Turn
7-Pin Connector
1 — Battery 5 — Ground
2 — Backup Lamps 6 — Left Stop/Turn
3 — Right Stop/Turn 7 — Running Lamps
4 — Electric Brakes 390 STARTING AND OPERATING

•Make sure that the radiator and coolant recovery
bottle hoses are not kinked or obstructed.
•Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean, also.
•Do not change the thermostat for Summer or Winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory cooling performance, poor gas
mileage, and increased emissions.
Brake System
In order to assure brake system performance, all brake
system components should be periodically inspected.
Refer to the “Maintenance Schedule” in Section 8 for the
proper maintenance intervals.
WARNING!
Riding the brakes can lead to brake failure and
possibly an accident. Driving with your foot resting
or riding on the brake pedal can result in abnormally
high brake temperatures, excessive lining wear, and
possible brake damage. You wouldn’t have your full
braking capacity in an emergency.
Fluid Level Check — Brake Master Cylinder
The fluid level of the master cylinder should be checked
when performing under the hood service, or immedi-
ately if the brake system warning lamp indicates system
failure.
The brake master cylinder has a translucent plastic
reservoir. On the outboard side of the reservoir, there is a
“MAX” dot and a “MIN” dot. The fluid level must be
kept within these two dots. Do not add fluid above the
MAX mark, because leakage may occur at the cap.
MAINTAINING YOUR VEHICLE 437
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