2004 JEEP GRAND CHEROKEE ECU

WARNING!
Cargo must be securely tied before driving your
vehicle. Improperly secured loads can fly off the
vehicle, particularly at high speeds, resulting in
personal injury or property damage. Follow the roof
rack ªCautionsº when carrying cargo on your roof
rack.
122 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

NOTE:Even if the transmission can be reset, it is
recommend that you see your dealer at your earliest
possible convenience. Your dealer has the proper diag-
nostic equipment to determine if the problem could
recur. If the transmission is cannot be reset, dealer service
is required.
Gear Ranges
DO NOT race the engine when shifting from P (Park) or
N (Neutral) position into another gear range.
PÐPark
Supplements the parking brake by locking the transmis-
sion. The engine can be started in this range. Never use P
(Park) while the vehicle is in motion. Apply the parking
brake when leaving the vehicle in this range. Always
apply the parking brake first, then place the selector in P
(Park) position.
WARNING!
Unintended movement of a vehicle could injure
those in and near the vehicle. As with all vehicles,
you should never exit a vehicle while the engine is
running. Before exiting a vehicle, you should always
shift the vehicle into P (Park), remove the key from
the ignition, and apply the parking brake. Once the
key is removed from the ignition, the transmission
shift lever is locked in the P (Park) position, securing
the vehicle against unwanted movement. Further-
more, you should never leave children unattended
inside a vehicle.
The following indicators should be used to ensure that
you have engaged the transmission shift lever into the P
(Park) position:
STARTING AND OPERATING 181
5

mode allows the front and rear wheels to rotate at
different speeds which eliminates driveline binding and
component wear that is normally associated with driving
the vehicle in the 4 PART TIME position on dry hard
surfaced roads. This feature provides the safety, security,
and convenience of operating in 4 wheel drive at all times
regardless of road conditions.
When additional traction is required, the 4 PART TIME
and 4LO positions can be used to lock the front and rear
driveshafts together through the transfer case inter-axle
differential and force the front and rear driveshafts to
rotate at the same speed. This is accomplished by simply
moving the shift lever to these positions. The 4 PART
TIME and 4LO positions are intended for loose, slippery
road surfaces only. Driving in the 4 PART TIME and 4LO
positions on dry hard surfaced roads may cause in-
creased tire wear and damage to driveline components.The PART TIME indicator light, located in the instrument
panel, alerts the driver that a four wheel drive mode
which locks the front and rear driveshafts together has
been selected. This light illuminates when the transfer
case is shifted to either the 4 PART TIME or 4LO
positions. There is no light for the 2WD, 4 FULL TIME, or
N (Neutral) positions.
NOTE:Do not attempt to make a shift while only the
front or rear wheels are spinning. The Selec-Tracttrans-
fer case is not equipped with a synchronizer and there-
fore the front and rear driveshaft speeds must be equal
for the shift to take place. Shifting while only the front or
rear wheels are spinning can cause damage to the trans-
fer case.
When operating your vehicle in 4LO, the engine speed is
approximately three times that of the 4 ALL TIME
position at a given road speed. Take care not to overspeed
the engine and do not exceed 25 mph (40 km/h).
STARTING AND OPERATING 187
5

WARNING!
Improper towing can lead to an injury accident.
Follow these guidelines to make your trailer towing
as safe as possible:
²Be sure a trailer is loaded heavier in front, about 10%
to 15% of gross trailer weight. Loads balanced over the
wheels or heavier in the rear cause the trailer to sway
severelyside to side which will cause loss of control of
the vehicle and trailer. Failure to load trailers heavier
in front is the cause of many trailer related accidents.
²Donotinterconnect the hydraulic brake system of
your vehicle with that of the trailer. This could cause
inadequate braking and possible personal injury.
²Trailer brakes are required for trailers in excess of
2,000 lbs (907 kg).
²Donotconnect a trailer lighting system directly to the
lighting system of your vehicle. Use an approved
trailer wiring harness. Failure to do so could damage
the vehicle electrical system and/or result in personal
injury.
²When hauling cargo or towing a trailer,do notover-
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to brakes,
axle, engine, transmission, steering, suspension, body
structure or tires.
²Make certain that the load is secured in the trailer and
will not shift during travel.
STARTING AND OPERATING 227
5

WARNING!
²Always store the jack, lug wrench and spare, flat
or damaged tire securely in the proper place.
Never leave them loose in the vehicle where they
could become dangerous projectiles during a
quick stop or collision.
²The jack is designed to use as a tool for changing
tires only. The jack should not be used to lift the
vehicle for service purposes, unless suitable sup-
ports are placed under the vehicle as a safety
measure, The vehicle should be jacked on a firm
level surface only. Avoid ice or slippery areas.
Spare Tire Location
To Remove the Spare Tire
1. Open the liftgate.
2. Grasp the cover on both sides at the edge adjacent to
the carpet depressions and lift the cover to unlatch.The
cover may be placed forward to lean against the rear
WHAT TO DO IN EMERGENCIES 239
6

9. Tighten the lug nuts securely in a crisscross pattern.
Have an authorized service technician check that the
torque is 85-115 ft.lbs. (115-156 N´m) as soon as possible.
10. Secure the jack, lug wrench, jack handle and tire in
the proper locations.WARNING!
²A loose tire or jack thrown forward in a collision
or hard stop could injure someone in the vehicle.
Always stow the jack parts and the extra tire and
wheel in the places provided.
²Carefully follow these tire changing warnings to
help prevent personal injury or damage to your
vehicle:
²Always park on a firm, level surface as far from the
edge of the roadway as possible before raising the
vehicle.
²Block the wheel diagonally opposite the wheel to be
raised.
²Apply the parking brake firmly before jacking.
²Never start the engine with the vehicle on a jack.
WHAT TO DO IN EMERGENCIES 245
6

NOTE:To start the vehicle following connection of a
booster battery, the Security Alarm System must first be
disabled by cycling a front door key cylinder or by using
the keyless entry transmitter.
WARNING!
Jump starting can be dangerous. To avoid personal
injury or damage to electrical components in vehicle,
observe the following warnings:
²Battery fluid is a corrosive acid solution and can burn
or even blind you. Don't allow battery fluid to contact
your eyes, skin, or clothing. Don't lean over a battery
when attaching clamps. If acid splashes in eyes or on
skin, flush the area immediately with large amounts of
water.
²Do not use a booster battery or any other booster
source that has a greater than 12±volt system, i.e., do
not use a 24±volt power source.
²Never attempt to jump start a discharged battery that
is frozen, because it could rupture or explode during
jump starting.
²Be sure your vehicle is not touching the jump start
vehicle.
²Observe all Battery Warnings in Section 7 of this
manual, while jump starting your vehicle.
WHAT TO DO IN EMERGENCIES 247
6

Hoses and Vacuum/Vapor Harnesses
Inspect surfaces of hoses and nylon tubing for evidence
of heat and mechanical damage. Hard or soft spots,
brittle rubber, cracking, tears, cuts, abrasions, and exces-
sive swelling indicate deterioration of the rubber.
Pay particular attention to the hoses nearest to high heat
sources such as the exhaust manifold. Inspect hose rout-
ing to be sure hoses do not touch any heat source or
moving component that may cause heat damage or
mechanical wear.
Insure nylon tubing in these areas has not melted or
collapsed. Inspect all hose connections such as clamps
and couplings to make sure they are secure and no leaks
are present. Components should be replaced immedi-
ately if there is any evidence of degradation that could
cause failure.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically.
Refer to the appropriate ªMaintenance Scheduleº in
Section 8 for suggested service 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.
Brake and Power Steering System Hoses
When servicing the vehicle for scheduled maintenance,
inspect surface of hoses for evidence of heat and me-
chanical damage. Hard and brittle rubber, cracking, tears,
274 MAINTAINING YOUR VEHICLE