2023 JEEP WRANGLER brake fluid

STARTING AND OPERATING143
N (Neutral)
Neutral — This range disengages both the front and rear
driveshafts from the powertrain. To be used for flat towing
behind another vehicle
Úpage 176.
4L
Four-Wheel Drive Low Range — This range provides low
speed four-wheel drive. It maximizes torque to the front
driveshaft, forcing the front and rear wheels to rotate at
the same speed. This range provides additional traction
and maximum pulling power for loose, slippery road
surfaces only. Do not exceed 25 mph (40 km/h).
This transfer case is designed to be driven in the
two-wheel drive position (2H) or four-wheel drive position
(4H AUTO) for normal street and highway conditions on dry
hard surfaced roads.
For variable driving conditions, the 4H AUTO mode can be
used. In this mode, the front axle is engaged, but the
vehicle's power is sent to the rear wheels. Four-wheel drive
will be automatically engaged when the vehicle senses a loss of traction. Because the front axle is engaged, this
mode will result in lower fuel economy than the 2H mode.
In the event that additional traction is required, the
transfer case 4H and 4L positions can be used to lock the
front and rear driveshafts together, forcing the front and
rear wheels to rotate at the same speed. The 4H and 4L
positions are intended for loose, slippery road surfaces
only and not intended for normal driving. Driving in the 4H
and 4L positions on hard-surfaced roads will cause
increased tire wear and damage to the driveline
components. For further information on shifting into 4H or
4L
Úpage 143.
The instrument cluster alerts the driver that the vehicle is
in four-wheel drive, and the front and rear driveshafts are
locked together. The light will illuminate when the transfer
case is shifted into the 4H position.
When operating your vehicle in 4L, the engine speed will
be approximately three times (four times for Rubicon
models) that of the 2H or 4H positions at a given road
speed. Take care not to overspeed the engine.
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.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
Shifting Procedures
2H TO 4H AUTO OR 4H AUTO TO 2H
Shifting between 2H and 4H AUTO can be made with the
vehicle stopped or in motion. The preferred shifting speed would be 0 to 45 mph (72 km/h). With the vehicle in
motion, the transfer case will engage/disengage faster if
you momentarily release the accelerator pedal after
completing the shift. Do not accelerate while shifting the
transfer case. Apply a constant force when shifting the
transfer case lever.
2H/4H AUTO TO 4H PART TIME OR 4H PART
TIME TO 2H/4H AUTO
Shifting between 2H/4H AUTO to 4H PART TIME can be
made with the vehicle stopped or in motion. The preferred
shifting speed would be 0 to 45 mph (72 km/h). With the
vehicle in motion, the transfer case will engage/disengage
faster if you momentarily release the accelerator pedal
after completing the shift. Do not accelerate while shifting
the transfer case. Apply a constant force when shifting the
transfer case lever.
NOTE:
 Do not attempt to make a shift while only the front or
rear wheels are spinning. 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 transfer case.
 Delayed shifts out of four-wheel drive may be experi -
enced due to uneven tire wear, low or uneven tire pres -
sures, excessive vehicle loading, or cold temperatures.
 Shifting effort will increase with speed, this is normal.
During cold weather, you may experience increased effort
in shifting until the transfer case fluid warms up. This is
normal.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the (N)
Neutral position without first fully engaging the parking
brake. The transfer case (N) Neutral position
disengages both the front and rear driveshafts from the
powertrain, and will allow the vehicle to roll, even if the
automatic transmission is in PARK (or manual
transmission is in gear). The parking brake should
always be applied when the driver is not in the vehicle.
4

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170STARTING AND OPERATING
Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the driver,
all passengers, options and cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo
area so that the GAWR of each axle is not exceeded.
Each axle GAWR is determined by the components in the
system with the lowest load carrying capacity (axle,
springs, tires or wheels). Heavier axles or suspension
components sometimes specified by purchasers for
increased durability do not necessarily increase the
vehicle's GVWR.
Tire Size
The tire size on the Vehicle Certification Label represents
the actual tire size on your vehicle. Replacement tires
must be equal to the load capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size
listed.
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 commercial
scale to ensure that the GVWR has not been exceeded.
The weight on the front and rear of the vehicle should then
be determined separately to be sure that the load is
properly distributed over the 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 effect
on the way your vehicle steers and handles and the way
the brakes operate.
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 review this
information to tow your load as efficiently and safely as
possible.
To maintain the New Vehicle Limited Warranty coverage,
follow the requirements and recommendations in this
manual concerning vehicles 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 tongue
weight. The total load must be limited so that you do not
exceed the GVWR
Úpage 169.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus the weight of all
cargo, consumables and equipment (permanent or
temporary) loaded in or on the trailer in its "loaded and
ready for operation" condition.
The recommended way to measure GTW is to put your fully
loaded trailer on a vehicle scale. The entire weight of the
trailer must be supported by the scale.
WARNING!
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.
Overloading can shorten the life of your vehicle.

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182STARTING AND OPERATING
DRIVING ACROSS AN INCLINE
If at all possible, avoid driving across an incline. If it is
necessary, know your vehicle's abilities. Driving across an
incline places more weight on the downhill wheels, which
increases the possibilities of a downhill slide or rollover.
Make sure the surface has good traction with firm and
stable soils. If possible, transverse the incline at an angle
heading slightly up or down.
IF YOU STALL OR BEGIN TO LOSE HEADWAY
If you stall or begin to lose headway while climbing a steep
hill, allow your vehicle to come to a stop and immediately
apply the brake. Restart the engine and shift into
REVERSE. Back slowly down the hill allowing engine
braking to control the descent and apply your brakes, if
necessary, but do not allow the tires to lock.
Driving Through Water
Extreme care should be taken crossing any type of water.
Water crossings should be avoided, if possible, and only
be attempted when necessary in a safe, responsible
manner. Only drive through areas which are designated
and approved. Tread lightly and avoid damage to the
environment. Know your vehicle's abilities and be able to
recover it if something goes wrong. Never stop or shut a
vehicle off when crossing deep water unless you ingested
water into the engine air intake. If the engine stalls, do not
attempt to restart it. Determine if it has ingested water
first. The key to any crossing is low and slow. Shift into
FIRST gear (manual transmission), or DRIVE (automatic
transmission), with the transfer case in the 4L position
and proceed very slowly with a constant slow speed of {3
to 5 mph (5 to 8 km/h) maximum} and light throttle. Keep
the vehicle moving; do not try to accelerate through the
crossing. After crossing any water higher than the bottom
of the axle differentials, inspect all of the vehicle fluids for
signs of water ingestion.
BEFORE YOU CROSS ANY TYPE OF WATER
As you approach any type of water, you need to determine
if you can cross it safely and responsibly. If necessary, get
out and walk through the water or probe it with a stick. You
need to be sure of its depth, approach angle, current and
bottom condition. Be careful of murky or muddy waters;
check for hidden obstacles. Make sure you will not be
intruding on any wildlife, and you can recover the vehicle
if necessary. The key to a safe crossing is the water depth,
current and bottom conditions. On soft bottoms, the
vehicle will sink in, effectively increasing the water level on
the vehicle. Be sure to consider this when determining the
depth and the ability to safely cross.
CROSSING PUDDLES, POOLS, FLOODED
AREAS OR OTHER STANDING WATER
Puddles, pools, flooded or other standing water areas
normally contain murky or muddy waters. These water
types normally contain hidden obstacles and make it
difficult to determine an accurate water depth, approach
angle, and bottom condition. Murky or muddy water holes
are where you want to hook up tow straps prior to entering.
This makes for a faster, cleaner and easier vehicle
recovery. If you are able to determine you can safely cross,
than proceed using the low and slow method.
WARNING!
Driving across an incline increases the risk of a rollover,
which may result in severe injury.
WARNING!
If the engine stalls or you lose headway or cannot make
it to the top of a steep hill or grade, never attempt to
turn around. To do so may result in tipping and rolling
the vehicle, which may result in severe injury. Always
back carefully straight down a hill in REVERSE. Never
back down a hill in NEUTRAL using only the vehicle
brakes. Never drive diagonally across a hill, always drive
straight up or down.
CAUTION!
Water ingestion into the axles, transmission, transfer
case, engine or vehicle interior can occur if you drive
too fast or through too deep of water. Water can
cause permanent damage to engine, driveline or
other vehicle components, and your brakes will be
less effective once wet and/or muddy.
 When driving through water, do not exceed 5 mph
(8 km/h). Always check water depth before entering
as a precaution, and check all fluids afterward.
Driving through water may cause damage that may
not be covered by the New Vehicle Limited Warranty.
CAUTION!
Muddy waters can reduce the cooling system
effectiveness by depositing debris onto the radiator.

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290SAFETY
PERIODIC SAFETY CHECKS YOU SHOULD
M
AKE OUTSIDE THE VEHICLE
Tires
Examine tires for excessive tread wear and uneven wear
patterns. Check for stones, nails, glass, or other objects
lodged in the tread or sidewall. Inspect the tread for cuts
and cracks. Inspect sidewalls for cuts, cracks, and bulges.
Check the lug nut/bolt torque for tightness. Check the
tires (including spare) for proper cold inflation pressure.
Lights
Have someone observe the operation of brake lights and
exterior lights while you work the controls. Check turn
signal and high beam indicator lights on the instrument
panel.
Door Latches
Check for proper closing, latching, and locking.
Fluid Leaks
Check area under vehicle after overnight parking for fuel,
coolant, oil, or other fluid leaks. Also, if gasoline fumes are
detected or if fuel or brake fluid leaks are suspected, the
cause should be located and corrected immediately.
EXHAUST GAS
The best protection against carbon monoxide entry into
the vehicle body is a properly maintained engine exhaust
system.
Whenever a change is noticed in the sound of the exhaust
system, when exhaust fumes can be detected inside the
vehicle, or when the underside or rear of the vehicle is
damaged, have an authorized dealer inspect the complete
exhaust system and adjacent body areas for broken,
damaged, deteriorated, or mispositioned parts. Open seams or loose connections could permit exhaust fumes
to seep into the passenger compartment. In addition,
inspect the exhaust system each time the vehicle is raised
for lubrication or oil change. Replace as required.
CARBON MONOXIDE WARNINGS
WARNING!
Exhaust gases can injure or kill. They contain carbon
monoxide (CO), which is colorless and odorless.
Breathing it can make you unconscious and can
eventually poison you. To avoid breathing (CO), follow
these safety tips:

Do not run the engine in a closed garage or in
confined areas any longer than needed to move your
vehicle in or out of the area.
 If you are required to drive with the trunk/liftgate/
rear doors open, make sure that all windows are
closed and the climate control BLOWER switch is set
at high speed. DO NOT use the recirculation mode.
 If it is necessary to sit in a parked vehicle with the
engine running, adjust your heating or cooling
controls to force outside air into the vehicle. Set the
blower at high speed.
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas, which can
kill. Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle
is stopped in an open area with the engine running
for more than a short period, adjust the ventilation
system to force fresh, outside air into the vehicle.
 Guard against carbon monoxide with proper mainte -
nance. Have the exhaust system inspected every
time the vehicle is raised. Have any abnormal condi -
tions repaired promptly. Until repaired, drive with all
side windows fully open.
 When exiting the vehicle, always make sure the igni -
tion is in the OFF position, remove the key fob from
the vehicle and lock your vehicle.

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306
SERVICING AND MAINTENANCE
SCHEDULED SERVICING — GASOLINE
ENGINE
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that service
is required for your vehicle. Operating conditions such as
frequent short-trips, trailer tow, extremely hot or cold
ambient temperatures will influence when the “Change
Oil” or “Oil Change Required” message is displayed. Have
your vehicle serviced as soon as possible, within the next
500 miles (805 km).On vehicles equipped with instrument cluster display, “Oil
Change Required” will be displayed and a single chime will
sound, indicating that an oil change is necessary.
On non-instrument cluster display equipped vehicles,
“Change Oil” will flash in the instrument cluster odometer
and a single chime will sound, indicating that an oil
change is necessary.
An authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone other than
an authorized dealer, the message can be reset by
referring to the steps described under Instrument Cluster
Display for further information
Úpage 108.
NOTE:Under no circumstances should oil change intervals
exceed 10,000 miles (16,000 km), 12 months or 350
hours of engine run time, whichever comes first. The 350
hours of engine run or idle time is generally only a concern
for fleet customers.
Once A Month Or Before A Long Trip:

Check the engine oil level.
 Check the windshield washer fluid level.
 Check the tire inflation pressures and look for unusual
wear or damage, rotate at the first sign of irregular
wear.
 Check the fluid levels of the coolant reservoir, brake
master cylinder, and power steering, and fill as needed.
 Check the function of all interior and exterior lights.

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308SERVICING AND MAINTENANCE
Mileage Or Time Passed (Whichever Comes
First):
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
110,000
120,000
130,000
140,000
150,000
Or Years: 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Or Kilometers:
32,000
48,000
64,000
80,000
96,000
112,000
128,000
144,000
160,000
176,000
192,000
208,000
224,000
240,000
Additional Inspections
Inspect the CV/Universal joints. X X X X X X X X X X X X X X
Inspect front suspension, tie rod ends, rear suspension,
and replace if necessary. X
XXXXXX
Inspect the front and rear axle fluid. XXXX
Inspect the brake linings, replace as necessary. XXXXXXX
Adjust parking brake on vehicles equipped with four
wheel disc brakes. X
XXXXXX
Inspect transfer case fluid. XXX
Additional Maintenance
Replace engine air cleaner filter. XXXXX
Replace cabin air filter. To be replaced every 12,000 miles (19,000 km).
Replace Spark Plugs – 2.0L Engine.
1X X
Replace spark plugs – 3.6L Engine.
1X
Flush and replace the engine, intercooler
(if equipped) coolant at 10 years or
150,000 miles (240,000 km) whichever comes first. X
X

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310SERVICING AND MAINTENANCE
SCHEDULED SERVICING — DIESEL ENGINE
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that service
is required for your vehicle. Operating conditions such as
frequent short-trips, trailer tow, extremely hot or cold
ambient temperatures will influence when the “Oil Change
Required” message is displayed. Have your vehicle
serviced as soon as possible, within the next 500 miles
(805 km).
An authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone other than
an authorized dealer, to reset the message
Úpage 108.
NOTE:Under no circumstances should oil change intervals
exceed 10,000 miles (16,000 km) or 12 months,
whichever comes first.
Engine Oil Filter Replacement
Residual oil in the housing may spill from the housing
when the new filter is installed if the residual oil is not
either removed from the housing or enough time has not
elapsed to allow the oil to drain back into the engine.
When servicing the oil filter on this engine, open the filter
cap approximately six turns until the cap o-ring is visible
and stop. Wait five minutes with the cap in this position to
allow dirty engine oil to drain back into the engine. After
five minutes, the cap and filter assembly can be removed
and discarded. When installing the new oil filter cartridge
assembly, ensure the cap is tightened to the specified
torque to prevent low oil pressure conditions. Once A Month Or Before A Long Trip:

Check engine oil level
 Check windshield washer fluid level
 Check the tire pressures and look for unusual wear or
damage
 Check the fluid levels of the coolant reservoir, brake
master cylinder, and fill as needed
 Check function of all interior and exterior lights

23_JL_OM_EN_USC_t.book Page 310

SERVICING AND MAINTENANCE311
MAINTENANCE PLAN — DIESEL FUEL UP TO B5 BIODIESEL
Refer to the maintenance plan for the required maintenance intervals.
At Every Oil Change Interval As Indicated By Oil Change Indicator System
Change oil and filter.
 Completely fill the Diesel Exhaust Fluid tank.
 Drain water from fuel filter assembly.
 Rotate the tires. Rotate at the first sign of irregular wear, even if it occurs before the oil indicator system turns on.
 Inspect battery and clean and tighten terminals as required.
 Inspect the CV/Universal joints.
 Inspect brake pads, shoes, rotors, drums, hoses and parking brake.
 Inspect engine cooling system protection and hoses.
 Inspect exhaust system.
 Inspect engine air cleaner filter if using in dusty or off-road conditions; replace engine air cleaner filter if necessary.
At Every Second Oil Change Interval As Indicated By Oil Change Indicator System
Change fuel filter.8

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