check engine JEEP WRANGLER 2021 Owner handbook (in English)

To Manually Turn Off The Start Stop System
1. Push the STOP/START Off switch (located
on the switch bank). The light on the
switch will illuminate.
2. The STOP/START OFF message will ap-
pear in the instrument cluster. Refer to
“Instrument Cluster Display” in “Getting
To Know Your Instrument Panel” for fur-
ther information.3. At the next vehicle stop (after turning off
the STOP/START system), the engine will
not be stopped.
4. If the STOP/START system is manually
turned off, the engine can only be started
and stopped by cycling the ignition switch
5. The STOP/START system will reset itself
back to an ON condition every time the
key is turned off and back on.
To Manually Turn On The Start Stop System
1. Push the STOP/START Off switch (located
on the switch bank).
2. The light on the switch will turn off.
System Malfunction
If there is a malfunction in the STOP/START
system, the system will not shut down the
engine. A “SERVICE STOP/START SYSTEM”
message will appear in the instrument cluster
display. Refer to “Warning Lights And Mes-
sages” in “Getting To Know Your Instrument
Panel” for further information.If the “SERVICE STOP/START SYSTEM”
message appears in the instrument cluster
display, have the system checked by your
authorized dealer.
SPEED CONTROL
When engaged, the Speed Control takes over
accelerator operations at speeds greater than
25 mph (40 km/h).
The Speed Control buttons are located on the
right side of the steering wheel.
STOP/START OFF Switch
STARTING AND OPERATING
136

CAUTION!
Damage to the transmission may occur if
the transmission is shifted into PARK with
the transfer case in NEUTRAL (N) and the
engine running. With the transfer case in
NEUTRAL (N) ensure that the engine is
OFF before shifting the transmission into
PARK.
13. Attach the vehicle to the tow vehicle
using a suitable tow bar.
14. Release the parking brake.
15. Disconnect the negative battery cable,
and secure it away from the negative
battery post.
Shifting Out of NEUTRAL (N)
Use the following procedure to prepare your
vehicle for normal usage.
1. Bring the vehicle to a complete stop,
leaving it connected to the tow vehicle.
2. Firmly apply the parking brake.
3. Reconnect the negative battery cable.
4. Turn the ignition to the LOCK position.
5. Turn the ignition to the ON/RUN position,
but do not start the engine.
6. Press and hold the brake pedal.
7. Shift the transmission into NEUTRAL.8. Shift the transfer case lever to the desired
position.
NOTE:
When shifting the transfer case out of
NEUTRAL (N), the engine should remain
OFF to avoid gear clash.
9. Shift the automatic transmission into
PARK, or place manual transmission in
NEUTRAL.
10. Release the brake pedal.
11. Disconnect vehicle from the tow vehicle.
12. Start the engine.
13. Press and hold the brake pedal.
14. Release the parking brake.
15. Shift the transmission into gear, release
the brake pedal (and clutch pedal on
manual transmissions), and check that
the vehicle operates normally.
STARTING AND OPERATING
144

General Information
The fuses protect electrical systems against
excessive current.
When a device does not work, you must check
the fuse element inside the blade fuse for a
break/melt.
Also, please be aware that when using power
outlets for extended periods of time with the
engine off may result in vehicle battery dis-
charge.
Totally Integrated Power Module
The Totally Integrated Power Module is lo-
cated in the engine compartment near the
battery. This center contains cartridge fuses,
mini fuses, and relays. A label that identifies
each component is printed on the inside of
the cover.
Cavity Cartridge Fuse Mini Fuse Description
J1 – – –
J2 30 Amp Pink – Transfer Case Module
J3 – – –
J4 25 Amp Clear – Driver Door Node
J5 25 Amp Clear – Passenger Door Node
J6 40 Amp Green – Anti-Lock Brake System (ABS) Pump/Stability Control
System
J7 30 Amp Pink – Anti-Lock Brake System (ABS) Valve/Stability Control
System
Totally Integrated Power Module
IN CASE OF EMERGENCY
150

SERVICING AND MAINTENANCE
SCHEDULED SERVICING......170
Scheduled Servicing — Gasoline
Engine....................170
Scheduled Servicing — Diesel Engine. .175
ENGINE COMPARTMENT......180
3.6L Engine.................180
2.8L Diesel Engine.............181
Checking Oil Level — Gasoline Engine. .182
Checking Oil Level — Diesel Engine . . .182
Cooling System...............182
Adding Washer Fluid............183
Brake System................183
Manual Transmission...........184Automatic Transmission..........184
Maintenance-Free Battery........186
Air Conditioner Maintenance.......186
DEALER SERVICE...........189
Windshield Wiper Blades.........189
RAISING THE VEHICLE........192
TIRES....................193
Tires — General Information.......193
Tire Types...................197
Spare Tires — If Equipped........198
Wheel And Wheel Trim Care.......199Tire Chains (Traction Devices).......200
Tire Rotation Recommendations.....201
STORING THE VEHICLE.......201
BODYWORK...............202
Body And Underbody Maintenance . . .202
Preserving The Bodywork.........202
INTERIORS...............204
Seats And Fabric Parts...........204
Plastic And Coated Parts..........205
Leather Parts.................205
Glass Surfaces...............206
SERVICING AND MAINTENANCE
169

SCHEDULED SERVICING
Scheduled Servicing — Gasoline Engine
The scheduled services listed in this manual
must be done at the times or mileages speci-
fied to protect your vehicle warranty and
ensure the best vehicle performance and re-
liability. More frequent maintenance may be
needed for vehicles in severe operating con-
ditions, such as dusty areas and very short
trip driving. Inspection and service should
also be done anytime a malfunction is sus-
pected.
The oil change indicator system will remind
you that it is time to take your vehicle in for
scheduled maintenance.
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.The oil change indicator message will illumi-
nate approximately 7,000 miles
(11,200 km) after the most recent oil change
was performed. Have your vehicle serviced as
soon as possible, within 500 miles (800 km).
However, an earlier oil change at 4,500 miles
(7,500 km) may be required if the vehicle is
operated under “Severe Duty Conditions”
later in this section.
NOTE:
• The oil change indicator message will not
monitor the time since the last oil change.
Change your vehicle's oil if it has been
6 months since your last oil change even if
the oil change indicator message is NOT
illuminated.
• Change your engine oil more often if you
drive your vehicle off-road for an extended
period of time.
• Under no circumstances should oil change
intervals exceed 7,500 miles (12,000 km)
or 6 months, whichever comes first.
Your authorized dealer will reset the oil
change indicator message after completing
the scheduled oil change.Once A Month Or Before A Long Trip
• Check the engine oil level about five min-
utes after a fully warmed engine is shut off.
Checking the oil level while the vehicle is
on level ground will improve the accuracy of
the oil level reading. Add oil only when the
level is at or below the ADD or MIN mark.
• Check the windshield washer solvent and
add if required.
• Check tire pressure and look for unusual
wear or damage. Rotate tires at the first
sign of irregular wear, even if it occurs
before the oil indicator system turns on.
• Inspect the battery and clean and tighten
the terminals as required.
• Check the fluid levels of coolant reservoir,
automatic transmission, brake master cyl-
inder and power steering and fill as needed.
• Check all lights and other electrical items
for correct operation.
SERVICING AND MAINTENANCE
170

WARNING!
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.
Severe Duty Conditions
†† Change the engine oil and engine oil filter
at every 4500 miles (7,500 km) or 6 months
if using your vehicle under any of the follow-
ing severe duty conditions:
• Stop and go driving.
• Driving in dusty conditions.
• Short trips of less than 10 miles (16 km).
• Trailer towing.
• Taxi, police, or delivery service (commercial
service).
• Off-road or desert operation.
Scheduled Servicing — Diesel Engine
At Each Stop for Fuel
• Check the engine oil level about five min-
utes after a fully warmed engine is shut off.
Checking the oil level while the vehicle is
on level ground will improve the accuracy of
the oil level reading. Add oil only when the
level is at or below the ADD or MIN mark.
• Check the windshield washer solvent, add
as required.
Once a Month
• Check tire pressure and look for unusual
wear or damage. Rotate tires at the first
sign of irregular wear, even if it occurs
before the oil indicator system turns on.
• Inspect the battery; clean and tighten the
terminals as required.
• Check the fluid levels of engine coolant/
antifreeze deaeration bottle, and brake
master cylinder, add as needed.
• Check all lights and all other electrical
items for correct operation.At Each Oil Change
• Change the engine oil filter.
• Inspect the exhaust system.
• Inspect brake hoses.
• Check the engine coolant/antifreeze level,
hoses, and clamps.
• Inspect engine accessory drive belts. Re-
place as necessary.
• Inspect for the presence of water in the fuel
filter/water separator unit.
Inspection and service should be performed
anytime a malfunction is observed or sus-
pected. Retain all receipts.
175

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