JEEP WRANGLER 2021 Owner handbook (in English)

* The actual interval for changing engine oil
and replacing the engine oil filter depends on
the vehicle usage conditions and is signalled
by the warning light or message in the instru-
ment panel. In all cases, never exceed 1 year/
15,000 miles (24,000 km).
** DOT 4 brake fluid is time based only;
mileage intervals do not apply.
WARNING!
• You can be badly injured working on or
around a motor vehicle. Do only service
work for which you have the knowledge
and the right equipment. If you have any
doubt about your ability to perform a
service job, take your vehicle to a com-
petent mechanic.
• Failure to properly inspect and maintain
your vehicle could result in a component
malfunction and effect vehicle handling
and performance. This could cause an
accident.
179

ENGINE COMPARTMENT3.6L Engine
1 — Integrated Power Module (Fuses) 7 — Washer Fluid Reservoir
2 — Battery8 — Engine Coolant Reservoir
3 — Engine Oil Dipstick 9 — Air Cleaner Filter
4 — Automatic Transmission Dipstick (Under Engine Cover) 10 — Coolant Pressure Cap
5 — Engine Oil Fill 11 — Power Steering Fluid Reservoir
6 — Brake Fluid Reservoir
SERVICING AND MAINTENANCE
180

2.8L Diesel Engine
1 — Integrated Power Module (Fuses) 6 — Washer Fluid Reservoir
2 — Battery 7 — Engine Oil Dipstick
3 — Engine Oil Fill 8 — Air Cleaner Filter
4 — Engine Coolant Reservoir 9 — Power Steering Fluid Reservoir
5 — Brake Fluid Reservoir
181

Checking Oil Level — Gasoline Engine
To ensure proper lubrication of your vehicle's
engine, the engine oil must be maintained at
the correct level. The engine oil level should
be checked five minutes after a warmed up
engine has been shut off.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil
level readings. Always maintain the oil level
within the SAFE zone on the dipstick. Adding
1 quart (0.95 liters) of oil when the reading is
at the bottom of the crosshatch zone will
result in a reading at the top of the cross-
hatch zone on these engines.
CAUTION!
Overfilling or underfilling the crankcase
will cause aeration or loss of oil pressure.
This could damage your engine.
Checking Oil Level — Diesel Engine
To assure proper engine lubrication, the en-
gine oil must be maintained at the correct
level. Check the oil level at regular intervals,
such as every fuel stop.For vehicles equipped with a Diesel Particu-
late Filter (DPF), it is acceptable to have an
oil level up to 3/8 inch (10 mm) above the
MAX line. Beyond 3/8 inch (10 mm) it is
recommended to change the oil.
The best time to check the engine oil level is
about five minutes after a fully warmed en-
gine is shut off.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil
level readings. Maintain the oil level between
the MIN and MAX markings on the dipstick.
Adding 1 U.S. Quart (0.95 L) of oil when the
reading is at the MIN mark will result in a
MAX reading on these engines.
Cooling System
WARNING!
• You or others can be badly burned by hot
engine coolant (antifreeze) or steam
from your radiator. If you see or hear
steam coming from under the hood, do
not open the hood until the radiator has
had time to cool. Never open a cooling
WARNING!
system pressure cap when the radiator
or coolant bottle is hot.
• Keep hands, tools, clothing, and jewelry
away from the radiator cooling fan when
the hood is raised. The fan starts auto-
matically and may start at any time,
whether the engine is running or not.
• When working near the radiator cooling
fan, disconnect the fan motor lead or
turn the ignition to the OFF mode. The
fan is temperature controlled and can
start at any time the ignition is in the ON
mode.
Engine Coolant Checks
Check the engine coolant (antifreeze) protec-
tion every 12 months (before the onset of
freezing weather, where applicable). If the
engine coolant (antifreeze) is dirty or rusty in
appearance, the system should be drained,
flushed and refilled with fresh engine coolant
(antifreeze). Check the front of the A/C con-
denser (if equipped) or radiator for any accu-
mulation of bugs, leaves, etc. If dirty, clean
SERVICING AND MAINTENANCE
182

by gently spraying water from a garden hose
vertically down the face of the A/C condenser
(if equipped) or the back of the radiator core.
Check the engine cooling system hoses for
brittle rubber, cracking, tears, cuts, and
tightness of the connection at the coolant
recovery bottle and radiator. Inspect the en-
tire system for leaks. DO NOT REMOVE THE
COOLANT PRESSURE CAP WHEN THE
COOLING SYSTEM IS HOT.
Adding Washer Fluid
The fluid reservoir for the windshield washers
and the rear window washer (if equipped) is
shared. The fluid reservoir is located in the
engine compartment. Be sure to check the
fluid level at regular intervals. Fill the reservoir
with windshield washer solvent only (not radia-
tor antifreeze). When refilling the washer fluid
reservoir, take some washer fluid and apply it to
a cloth or towel and wipe clean the wiper
blades; this will help blade performance.
To prevent freeze-up of your windshield
washer system in cold weather, select a solu-
tion or mixture that meets or exceeds the
temperature range of your climate. This rat-
ing information can be found on most washer
fluid containers.
WARNING!
Commercial windshield washer solvents
are flammable. They could ignite and burn
you. Care must be exercised when filling or
working around the washer solution.
Brake System
In order to assure brake system performance,
all brake system components should be in-
spected periodically. Refer to the “Mainte-
nance Plan” in this section for the proper
maintenance intervals.
WARNING!
Riding the brakes can lead to brake failure
and possibly a collision. Driving with your
foot resting or riding on the brake pedal
WARNING!
can result in abnormally high brake tem-
peratures, excessive lining wear, and pos-
sible brake damage. You would not have
your full braking capacity in an emergency.
Fluid Level Check — Brake Master Cylinder
The fluid level of the master cylinder should
be checked whenever the vehicle is serviced,
or immediately if the brake system warning
light is on. If necessary, add fluid to bring
level within the designated marks on the side
of the reservoir of the brake master cylinder.
Be sure to clean the top of the master cylin-
der area before removing cap. With disc
brakes, fluid level can be expected to fall as
the brake pads wear. Brake fluid level should
be checked when pads are replaced. If the
brake fluid is abnormally low, check the sys-
tem for leaks.
Refer to “Fluids And Lubricants” in “Techni-
cal Specifications” for further information.
183

WARNING!
• Use only manufacturer's recommended
brake fluid. Refer to “Fluids And Lubri-
cants” in “Technical Specifications” for
further information. Using the wrong
type of brake fluid can severely damage
your brake system and/or impair its per-
formance. The proper type of brake fluid
for your vehicle is also identified on the
original factory installed hydraulic mas-
ter cylinder reservoir.
• To avoid contamination from foreign
matter or moisture, use only new brake
fluid or fluid that has been in a tightly
closed container. Keep the master cylin-
der reservoir cap secured at all times.
Brake fluid in a open container absorbs
moisture from the air resulting in a lower
boiling point. This may cause it to boil
unexpectedly during hard or prolonged
braking, resulting in sudden brake fail-
ure. This could result in a collision.
• Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot en-
gine parts, causing the brake fluid to
WARNING!
catch fire. Brake fluid can also damage
painted and vinyl surfaces, care should
be taken to avoid its contact with these
surfaces.
• Do not allow petroleum based fluid to
contaminate the brake fluid. Brake seal
components could be damaged, causing
partial or complete brake failure. This
could result in a collision.
Manual Transmission
Fluid Level Check
Check the fluid level by removing the fill
plug. The fluid level should be between the
bottom of the fill hole and a point not more
than 3/16 of an inch (4.76 mm) below the
bottom of the hole.
Add fluid, if necessary, to maintain the
proper level.
Automatic Transmission
Fluid Level Check — Gasoline Engine
It is best to check the fluid level when the
transmission is at normal operating tempera-
ture (approximately 180°F/82°C). This oc-
curs after at least 15 miles (25 km) of driv-
ing. At normal operating temperature, the
fluid cannot be held comfortably between the
fingertips.
Use the following procedure to check the
transmission fluid level properly:
1. Park the vehicle on level ground.
2. Remove the engine cover by pulling it up
off the mounting studs (two in the front
and two in the rear).
3. Run the engine at normal idle speed for at
least 60 seconds, and leave the engine
running for the rest of this procedure.
4. Fully apply the parking brake, and press
the brake pedal.
SERVICING AND MAINTENANCE
184

5. Place the gear selector momentarily into
each gear position (allowing time for the
transmission to fully engage in each posi-
tion), ending with the transmission in
PARK.
6. Remove the dipstick, wipe it clean and
reinsert it until seated.
7. Remove the dipstick again and note the
fluid level on both sides. The fluid level
reading is only valid if there is a solid
coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be
full of fluid if the actual level is at or above
the hole. The fluid level should be be-
tween the HOT (upper) reference holes on
the dipstick at normal operating tempera-
ture. If the fluid level is low, add fluid
through the dipstick tube to bring it to the
proper level.Do not overfill.Use ONLY the
specified fluid (refer to "Fluids And Lubri-
cants" under “Technical Specifications”
for fluid specifications). After adding any
quantity of oil through the dipstick tube,
wait a minimum of two minutes for the oil
to fully drain into the transmission before
rechecking the fluid level.NOTE:
• The holes in the dipstick will be full of
fluid if the actual level is at or above the
hole.
• If it is necessary to check the transmis-
sion below the operating temperature,
the fluid level should be between the
two COLD (lower) holes on the dipstick
with the fluid at approximately 80°F
(27°C). If the fluid level is correctly
established at 80° F (27°C), it should
be between the HOT (upper) reference
holes when the transmission reaches
180° F (82°C). Remember it is best to
check the level at the normal operating
temperature.
CAUTION!
If the fluid temperature is below 50°F
(10°C) it may not register on the dipstick.
Do not add fluid until the temperature is
elevated enough to produce an accurate
reading. Run the engine at idle, in PARK,
to warm the fluid.8. Reinstall the engine cover and snap it
down securely onto the four mounting
studs.
9. Check for leaks. Release the parking
brake.
NOTE:
To prevent dirt and water from entering the
transmission after checking or replenishing
fluid, make sure that the dipstick cap is
properly reseated. It is normal for the dipstick
cap to spring back slightly from its fully
seated position, as long as its seal remains
engaged in the dipstick tube.
Fluid Level Check — 2.8L Turbo Diesel
Engine
The fluid level is preset at the factory and
does not require adjustment under normal
operating conditions. Routine fluid level
checks are not required, therefore the trans-
mission filler tube is capped and no dipstick
is provided. An authorized dealer can check
your transmission fluid level using a special
service dipstick.
185

If you notice fluid leakage or transmission
malfunction, visit an authorized dealer im-
mediately to have the transmission fluid level
checked. Operating the vehicle with an im-
proper fluid level can cause severe transmis-
sion damage.
Maintenance-Free Battery
Your vehicle is equipped with a maintenance-
free battery. You will never have to add water,
nor is periodic maintenance required.
WARNING!
• Battery fluid is a corrosive acid solution
and can burn or even blind you. Do not
allow battery fluid to contact your eyes,
skin, or clothing. Do not lean over a
battery when attaching clamps. If acid
splashes in eyes or on skin, flush the
area immediately with large amounts of
water. Refer to “Jump Starting Proce-
dure” in “In Case Of Emergency” for
further information.
• Battery gas is flammable and explosive.
Keep flame or sparks away from the
battery. Do not use a booster battery or
WARNING!
any other booster source with an output
greater than 12 Volts. Do not allow cable
clamps to touch each other.
• Battery posts, terminals, and related ac-
cessories contain lead and lead com-
pounds. Wash hands after handling.
CAUTION!
• It is essential when replacing the cables
on the battery that the positive cable is
attached to the positive post and the
negative cable is attached to the nega-
tive post. Battery posts are marked posi-
tive (+) and negative (-) and are identi-
fied on the battery case. Cable clamps
should be tight on the terminal posts
and free of corrosion.
• If a “fast charger” is used while the
battery is in the vehicle, disconnect both
vehicle battery cables before connecting
the charger to the battery. Do not use
a “fast charger” to provide starting volt-
age.
Air Conditioner Maintenance
For best possible performance, your air con-
ditioner should be checked and serviced by
an authorized dealer at the start of each warm
season. This service should include cleaning
of the condenser fins and a performance test.
Drive belt tension should also be checked at
this time.
WARNING!
• Use only refrigerants and compressor
lubricants approved by the manufac-
turer for your air conditioning system.
Some unapproved refrigerants are flam-
mable and can explode, injuring you.
Other unapproved refrigerants or lubri-
cants can cause the system to fail, re-
quiring costly repairs. Refer to Warranty
Information Book, located in your own-
er’s information kit, for further warranty
information.
• The air conditioning system contains re-
frigerant under high pressure. To avoid
risk of personal injury or damage to the
system, adding refrigerant or any repair
SERVICING AND MAINTENANCE
186

WARNING!
requiring lines to be disconnected
should be done by an experienced tech-
nician.
CAUTION!
Do not use chemical flushes in your air
conditioning system as the chemicals can
damage your air conditioning components.
Such damage is not covered by the New
Vehicle Limited Warranty.
Refrigerant Recovery And Recycling R-134a
— If Equipped
R-134a Air Conditioning Refrigerant is a
hydrofluorocarbon (HFC) that is an ozone-
friendly substance. The manufacturer recom-
mends that air conditioning service be per-
formed by an authorized dealer or other
service facilities using recovery and recycling
equipment.NOTE:
Use only manufacturer approved A/C system
PAG compressor oil and refrigerants.
Refrigerant Recovery And Recycling —
R–1234yf
R–1234yf Air Conditioning Refrigerant is a
hydrofluoroolefin (HFO) that is endorsed by
the Environmental Protection Agency and is
an ozone-friendly substance with a low
global-warming potential. The manufacturer
recommends that air conditioning service be
performed by an authorized dealer using re-
covery and recycling equipment.
NOTE:
Use only manufacturer approved A/C system
PAG compressor oil, and refrigerants.
Air Conditioning Filter Replacement (A/C Air
Filter)
WARNING!
Do not remove the cabin air filter while the
vehicle is running, or while the ignition is
in the ACC or ON/RUN mode. With the
cabin air filter removed and the blower
operating, the blower can contact hands
and may propel dirt and debris into your
eyes, resulting in personal injury.
The A/C air filter is located in the fresh air
inlet behind the glove compartment. Perform
the following procedure to replace the filter:
1. Open the glove compartment and remove
all contents.
2. Push in on the sides of the glove compart-
ment and lower the door.
187

3. Pivot the glove compartment downward.
4. Disengage the two retaining tabs that se-
cure the two air filter access doors to the
HVAC housing.5. Open the two air filter access doors.
6. Remove the two particulate air filters from
the HVAC air inlet housing. Pull the filter
elements straight out of the housing, one
at a time.7. Install the A/C air filter with the air filter
position indicators pointing in the same
direction as removal.
Glove Compartment
1 — Glove Compartment Travel Stops
2 — Glove Compartment
Air Filter Retaining Tabs
1 — Left Retaining Tab
2 — Right Retaining Tab
Air Filter Access Door Open
1—Air Conditioning Filter Access Door
2 — Air Conditioning Air FilterSERVICING AND MAINTENANCE
188