2005 JEEP GRAND CHEROKEE wheel torque

“TRACTION SYS DISABLED” message will be displayed
in the Electronic Vehicle Information Center (EVIC).
Refer to Section 4 of this manual.
To turn the system back ON, press the switch a second
time, until the “Traction Control Indicator Light” turns
off.When the Traction Control System has been turned off
using the switch, a feature of the system remains active.
This feature functions similar to a limited slip differential
and controls the wheel spin across an axle. If one wheel
on an axle is spinning faster than the other, the system
will apply the brake of the spinning wheel and allow
more engine torque to be applied to the wheel that is not
spinning.
NOTE:
•The “Traction Control Indicator Light” comes on mo-
mentarily each time the ignition switch is turned ON.
This will occur even if you used the switch to turn the
system OFF.
•Each time the ignition is turned ON, the Traction
Control System will be ON even if it was turned OFF
previously.
•The Traction Control System will make buzzing or
clicking sounds when it is active.
Traction Control Switch
122 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

ELECTRONIC STABILITY PROGRAM (ESP)— IF
EQUIPPED
WARNING!
ESP (Electronic Stability Program) cannot prevent
the natural laws of physics from acting on the
vehicle, nor can it increase the traction afforded. The
ESP cannot prevent accidents, including those re-
sulting from excessive speed in turns, or hydroplan-
ing. Only a safe, attentive, and skillful driver can
prevent accidents. The capabilities of an ESP-
equipped vehicle must never be exploited in a reck-
less or dangerous manner which could jeopardize
the user’s safety or the safety of others.
ESP (Electronic Stability Program) enhances directional
control and reduces driving wheel spin of the vehicle
under various driving conditions.ESP corrects for over/understeering of the vehicle by
applying brakes to the appropriate wheel. Engine torque
is also limited. The “ESP Indicator Light,” located in the
instrument cluster, starts to flash as soon as the tires lose
traction and the ESP system becomes active.ESP Indicator Light
124 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

than the other, the system will apply the brake of the
spinning wheel and allow more engine torque to be
applied to the wheel that is not spinning.
To improve the vehicle’s traction when driving with
snow chains, or starting off in deep snow, sand or gravel,
it may be desirable to switch off the ESP by pressing the
ESP switch.
With the ESP switched off, the engine torque reduction
and stability features are cancelled. Therefore, the en-
hanced vehicle stability offered by ESP is unavailable.
If the “ESP Indicator Light” begins to flash during
acceleration, ease up on the accelerator and apply as little
throttle as possible. Be sure to adapt your speed and
driving to the prevailing road conditions. When the “ESP
Indicator Light” is illuminated continuously, the ESP is
switched off. To return to the enhanced vehicle stability
offered by ESP, press the ESP switch (the “ESP IndicatorLight” in the instrument cluster goes out). Avoid spin-
ning one drive wheel. This may cause serious damage to
the drive train.
NOTE:
•The “ESP Indicator Light” comes on momentarily each
time the ignition switch is turned ON.
•Each time the ignition is turned ON, the ESP System
will be ON even if it was turned off previously.
•The ESP Control System will make buzzing or clicking
sounds when it is active.
There are two Electronic Vehicle Information Center
(EVIC) messages associated with the Electronic Stability
Control System. Refer to Section 4 of this manual.
ESP System Disabled
This message will be displayed if the ESP System has
been turned off using the switch, or if there is a tempo-
rary condition that will result in partial or no ESP
126 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

NOTE:The Electronic Stability Program (ESP) and
Traction Control (if equipped) should be turned OFF
before attempting to rock the vehicle. Refer to Section 3 of
this manual.
The least amount of accelerator pedal pressure to main-
tain the rocking motion without spinning the wheels or
racing the engine is most effective. Racing the engine or
spinning the wheels, due to the frustration of not freeing
the vehicle, may lead to transmission overheating and
failure. Allow the engine to idle with the transmission
selector in N (Neutral) for at least one minute after every
five rocking-motion cycles. This will minimize overheat-
ing and reduce the risk of transmission failure during
prolonged efforts to free a stuck vehicle.CAUTION!
When “rocking” a stuck vehicle by moving between
“First” and R (Reverse), do not spin the wheels faster
than 15 mph (24 km/h), or drivetrain damage may
result.
FOUR-WHEEL DRIVE OPERATION
Quadra-Trac IOperating
Instructions/Precautions — If Equipped
The Quadra-Trac Iis a single speed (HI range only)
transfer case which provides convenient full-time
4–wheel drive. No driver interaction is required. This
transfer case divides engine torque almost evenly with 48
percent of engine torque to the front axle and 52 percent
of engine torque to the rear axle. The Brake Traction
Control System (BTC), which combines standard ABS
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and Traction Control, provides resistance to any wheel
that is slipping to allow additional torque transfer to
wheels with traction.
NOTE:The Quadra-Trac Isystem is not appropriate
for conditions where LOW range is recommended. Refer
to “Off-Road Driving Tips” in this section.
Quadra-Trac IIOperating
Instructions/Precautions — If Equipped
The Quadra-Trac IItransfer case is fully automatic in the
normal driving 4 HI mode. The Quadra-Trac IItransfer
case provides three mode positions — four wheel drive
high range, neutral, and four wheel drive low range.
This transfer case is fully automatic in the 4 HI mode.
This transfer case divides engine torque almost evenly
with 48 percent of engine torque to the front axle and 52
percent of engine torque to the rear axle. When speed
differences are increased between the front and rear driveshafts, the transfer case can transmit up to 100 percent of
available engine torque to the front or rear drive shafts.
When additional traction is required, the 4 LOW position
can be used to lock the front and rear driveshafts together
and force the front and rear wheels to rotate at the same
speed. The 4 LOW position is intended for loose, slippery
road surfaces only. Driving in the 4 LOW position on dry
hard surfaced roads may cause increased tire wear and
damage to driveline components.
When operating your vehicle in 4 LOW, the engine speed
is approximately three times that of the 4 HI position at a
given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).
Proper operation of four wheel drive vehicles depends on
tires of equal size, type, and circumference on each
wheel. Any difference will adversely affect shifting and
cause damage to the transfer case.
240 STARTING AND OPERATING

the EVIC (Electronic Vehicle Information Center). Refer
to “Electronic Vehicle Information Center (EVIC)” in
Section 4 of this manual.
Quadra-DriveSystem — If Equipped
The optional Quadra-DriveSystem features three
torque transfer couplings. The couplings include ELSD
(Electronic Limited Slip Differential) front and rear axles
and Quadra-Trac IItransfer case. The optional ELSD
axles are fully automatic and require no driver input to
operate. Under normal driving conditions the units func-
tion as standard axles balancing torque evenly between
left and right wheels. With a traction difference between
left and right wheels the coupling will sense a speed
difference. As one wheel begins to spin faster than the
other, torque will automatically transfer from the wheel
that has less traction to the wheel that has traction. While
the transfer case and axle couplings differ in design, theiroperation is similar. Follow the Quadra-Trac IItransfer
case shifting information, preceding this section, for
shifting this system.PARKING BRAKE
To set the parking brake, pull the lever up as firmly as
possible. When the parking brake is applied with the
ignition ON, the “Brake Warning Light” in the instru-
ment cluster will light.
NOTE:The instrument cluster “Brake Warning Light”
indicates only that the parking brake is applied. It does
not indicate the degree of brake application.
244 STARTING AND OPERATING

build up between the tire tread and the road. This
hydroplaning action can cause loss of traction, braking
ability, and control.
•After going through deep water or a car wash, brakes
may become wet, resulting in decreased performance
and unpredictable braking action. Dry the brakes by
gentle, intermittent pedal action while driving at very
slow speeds.
VARI-LOK REAR AXLE — IF EQUIPPED
The optional Vari-Lok axle is fully automatic and requires
no driver input to operate. Under normal driving condi-
tions the unit functions as a standard axle balancing
torque evenly between left and right wheels. With a
traction difference between left and right wheels the
coupling will sense a speed difference. As one wheel
begins to spin faster than the other, torque will automati-
cally transfer from the wheel that has less traction to the
wheel that has traction.
ON-ROAD DRIVING TIPS
Utility vehicles have higher ground clearance and a
narrower track to make them capable of performing in a
wide variety of off-road applications. Specific design
characteristics give them a higher center of gravity than
ordinary cars.
An advantage of the higher ground clearance is a better
view of the road, allowing you to anticipate problems.
They are not designed for cornering at the same speeds as
conventional 2-wheel drive vehicles any more than low-
slung sports cars are designed to perform satisfactorily in
off-road conditions. If at all possible, avoid sharp turns or
abrupt maneuvers. As with other vehicles of this type,
failure to operate this vehicle correctly may result in loss
of control or vehicle rollover.
STARTING AND OPERATING 249
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After Driving Off-Road
Off-road operation puts more stress on your vehicle than
does most on-road driving. After going off-road it is
always a good idea to check for damage. That way you
can get any problems taken care of right away and have
your vehicle ready when you need it.
•Completely inspect the underbody of your vehicle.
Check tires, body structure, steering, suspension, and
exhaust system for damage.
•Check threaded fasteners for looseness, particularly on
the chassis, drivetrain components, steering, and sus-
pension. Retighten them, if required, and torque to the
values specified in the Service Manual.
•Check for accumulations of plants or brush. These
things could be a fire hazard. They might hide damage
to fuel lines, brake hoses, axle pinion seals, and
propeller shafts.
•After extended operation in mud, sand, water, or
similar dirty conditions, have brake rotors, wheels,
brake linings, and axle yokes inspected and cleaned as
soon as possible.
WARNING!
Abrasive material in any part of the brakes may
cause excessive wear or unpredictable braking. You
might not have full braking power when you need it
to prevent an accident. If you have been operating
your vehicle in dirty conditions, get your brakes
checked and cleaned as necessary.
•If you experience unusual vibration after driving in
mud, slush or similar conditions, check the wheels for
impacted material. Impacted material can cause a
wheel imbalance and freeing the wheels of it will
correct the situation.
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