2021 JEEP WRANGLER check engine

AUTOMATIC
TRANSMISSION — IF
EQUIPPED
CAUTION!
Damage to the transmission may occur if
the following precautions are not ob-
served:
• Shift into or out of PARK or REVERSE
only after the vehicle has come to a
complete stop.
• Do not shift between PARK, REVERSE,
NEUTRAL, or DRIVE when the engine is
above idle speed.
• Before shifting into any gear, make sure
your foot is firmly pressing the brake
pedal.
NOTE:
You must press and hold the brake pedal
while shifting out of PARK.
WARNING!
•Never use the PARK position as a substi-
tute for the parking brake. Always apply
the parking brake fully when exiting the
vehicle to guard against vehicle move-
ment and possible injury or damage.
• Your vehicle could move and injure you
and others if it is not in PARK. Check by
trying to move the gear selector out of
PARK with the brake pedal released.
Make sure the transmission is in PARK
before exiting the vehicle.
• It is dangerous to shift out of PARK or
NEUTRAL if the engine speed is higher
than idle speed. If your foot is not firmly
pressing the brake pedal, the vehicle
could accelerate quickly forward or in
reverse. You could lose control of the
vehicle and hit someone or something.
Only shift into gear when the engine is
idling normally and your foot is firmly
pressing the brake pedal.
• Unintended movement of a vehicle
could injure those in or near the vehicle.
As with all vehicles, you should never
WARNING!
exit a vehicle while the engine is run-
ning. Before exiting a vehicle always
come to a complete stop, then apply the
parking brake, shift the transmission
into PARK, turn the engine OFF, and
remove the ignition key. Once the key is
removed, the transmission is locked in
PARK, securing the vehicle against un-
wanted movement.
• When exiting the vehicle, always remove
the ignition key from the vehicle and
lock the vehicle.
• Never leave children alone in a vehicle,
or with access to an unlocked vehicle.
Allowing children to be in a vehicle un-
attended is dangerous for a number of
reasons. A child or others could be seri-
ously or fatally injured. Children should
be warned not to touch the parking
brake, brake pedal or the transmission
gear selector.
• Do not leave the ignition key in or near
the vehicle (or in a location accessible to
children). A child could operate power
STARTING AND OPERATING
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Possible Reasons The Engine Does Not
AUTO STOP
Prior to engine shut down, the system will
check many safety and comfort conditions to
see if they are fulfilled. In following situations
the engine will not stop:
• Driver’s seat belt is not buckled.
• Outside temperature is less than 1°F
(–17°C) or greater than 104°F (40°C).
• Actual cabin temperature is significantly
different than temperature set on Auto
HVAC.
• HVAC is set to full defrost mode.
• Engine has not reached normal operating
temperature.
• Battery discharged.
• When driving in REVERSE.
• Hood is open.
• Vehicle is in 4LO transfer case mode.It may be possible for the vehicle to be driven
several times without the STOP/START sys-
tem going into a STOP/START READY state
under more extreme conditions of the items
listed above.
To Start The Engine While In The STOP/
START AUTO STOP ACTIVE Mode
When the gear selector is in NEUTRAL, the
engine will start when the clutch pedal is
pressed. The vehicle will go into STOP/START
SYSTEM NOT READY mode until the vehicle
speed is greater than 3 mph (5 km/h).
Conditions that will cause the engine to start
automatically while in STOP/START AUTO STOP
ACTIVE mode
The Engine Will Start Automatically When:
• Actual cabin temperature is significantly
different than temperature set on Auto
HVAC.
• HVAC is set to full defrost mode.
• STOP/START AUTO STOP ACTIVE time ex-
ceeds 5 minutes.• Battery voltage drops too low.
• Low brake vacuum e.g. after several brake
pedal applications.
•
Vehicle is moving faster than 3 mph (5 km/h).
• STOP/START OFF switch is pressed.
• 4WD system is put into 4LO mode.
Conditions that force a manual key cycle
start while in STOP/START AUTO STOP AC-
TIVE mode:
The Engine Will Not Start Automatically If:
• The driver’s seatbelt was unbuckled
• The engine hood has been opened
• A STOP/START system error occurs
The engine may then only be restarted with
an ignition key cycle. The STOP/START KEY
START REQUIRED message will appear in
the instrument cluster under these condi-
tions. Refer to “Instrument Cluster Display”
in “Getting To Know Your Instrument Panel”
for further information.
135

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
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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