2021 JEEP WRANGLER check engine light

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

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

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

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

After 25 miles (40 km), check the lug nut/
bolt torque to be sure that all the lug nuts/
bolts are properly seated against the wheel.
WARNING!
To avoid the risk of forcing the vehicle off
the jack, do not tighten the lug nuts fully
until the vehicle has been lowered. Failure
to follow this warning may result in per-
sonal injury.
FUEL REQUIREMENTS —
GASOLINE ENGINES
This engine is designed to meet all emissions
regulations and provide excellent fuel
economy and performance when using high
quality unleaded gasoline with a minimum
research octane rating (RON) of 91.
Light spark knock at low engine speeds is not
harmful to your engine. However, continued
heavy spark knock at high speeds can cause
damage, and immediate service is required.
Poor quality gasoline can cause problems
such as hard starting, stalling, and hesita-
tions. If you experience these symptoms, try
another brand of gasoline before considering
service for the vehicle.
Ethanol
The manufacturer recommends that your ve-
hicle be operated on fuel containing no more
than 15% ethanol. Purchasing your fuel from
a reputable supplier may reduce the risk of
exceeding this 15% limit and/or of receiving
fuel with abnormal properties. It should also
be noted that an increase in fuel consump-tion should be expected when using ethanol-
blended fuels, due to the lower energy con-
tent of ethanol. Problems that result from
using methanol/gasoline or E-85 ethanol
blends are not the responsibility of the
manufacturer.
CAUTION!
Use of fuel with Ethanol content higher
than 15% may result in engine malfunc-
tion, starting and operating difficulties,
and materials degradation. These adverse
effects could result in permanent damage
to your vehicle.
FUEL REQUIREMENTS —
DIESEL ENGINES
Use Premium Quality Diesel fuels with a
Cetane rating of 50 or higher, and meeting
the EN590 standard are highly recom-
mended. See your authorized dealer for fur-
ther information regarding fuels available in
your area.
Torque Patterns
209

Accessories..................212
Mopar...................212
Adding Fuel.................139
AirBag .....................93
Advance Front Air Bag.........93
Air Bag Operation.............94
Air Bag Warning Light..........92
Enhanced Accident Response . .98, 168
Event Data Recorder (EDR)......168
Front Air Bag...............93
If A Deployment Occurs.........97
Knee Impact Bolsters..........95
Maintaining Your Air Bag System . . .98
Transporting Pets............112
Air Bag Light............58, 92, 113
Air Bag Maintenance.............98
Air Conditioner Maintenance.......186
Air Conditioning Filter.........38, 187
Air Conditioning, Operating Tips......37
Air Conditioning Refrigerant. . . .186, 187
Air Conditioning System.......37, 186
Air Pressure, Tires..............193
Alarm (Security Alarm).........18, 61
Alterations/Modifications, Vehicle......4
Antifreeze (Engine Coolant)........210Anti-Lock Brake System (ABS).......68
Anti-Lock Warning Light...........61
Arming System (Security Alarm)......18
Assist, Hill Start................70
Audio Jack...............219, 226
Audio Settings................218
Automatic Headlights............29
Automatic Oil Change Indicator......58
Automatic Temperature Control (ATC) . . .37
Automatic Transmission..........127
Fluid Level Check...........184
Fluid Type................211
Autostick...................128
Axle Fluid...................211
Axle Lock...................132
Battery..................60, 186
Charging System Light.........60
Belts, Seat
.................
.113
Brake Assist System.............69
Brake Control System, Electronic.....69
Brake Fluid..............183, 211
Brake System................183
Fluid Check...............183
Master Cylinder.............183Parking..................121
Brake/Transmission Interlock.......127
Bulb Replacement..........146, 147
Bulbs, Light.................114
Capacities, Fluid..............210
Caps, Filler
Fuel....................139
Oil (Engine)...............180
Carbon Monoxide Warning.........112
Car Washes..................202
CD (Compact Disc) Player.........218
Center High Mounted Stop Light.....149
Chains, Tire..................200
Changing A Flat Tire.........154, 192
Checking Your Vehicle For Safety. . . .112
Checks, Safety................112
Child Restraints
How To Stow An Unused ALR Seat
Belt....................110
Cleaning
Wheels..................199
Climate Control................33
Manual...................33
Clock Setting.............218, 221
INDEX
259

Cold Weather Operation..........117
Compact Spare Tire.............198
Connector
UCI ....................233
Universal Consumer Interface
(UCI)...................233
Cooling System...............182
Coolant Capacity............210
Inspection................182
Selection Of Coolant (Antifreeze) . .210
Customer Assistance............242
Daytime Running Lights...........29
Dealer Service................189
Defroster, Windshield............113
Delay (Intermittent) Wipers.........31
Diagnostic System, Onboard........64
Diesel Engine Maintenance........175
Diesel Fuel..................209
Diesel Fuel Requirements.........209
Dimmer Switch, Headlight.........29
Dipsticks
Oil (Engine)...............182
Disabled Vehicle Towing..........165
Disarming, Security System.........18
Doors......................19Driver's Seat Back Tilt............21
Electronic Brake Control System......69
Anti-Lock Brake System........68
Electronic Roll Mitigation.......75
Traction Control System........71
Electronic Speed Control (Cruise
Control)..................136
Electronic Stability Control (ESC).....71
Electronic Throttle Control Warning
Light.....................60
Emergency Brake..............121
Emergency, In Case Of
Jacking..............154, 192
Jump Starting..............160
Engine.....................180
Break-In Recommendations.....121
Compartment...........180, 181
Compartment Identification . .180, 181
Cooling.................
.182
Exhaust Gas Caution..........112
Fails To Start...............118
Flooded, Starting............118
Fuel Requirements...........210
Jump Starting..............160
Oil .....................210
Oil Change Interval...........58Oil Filler Cap..............180
Oil Selection..............210
Overheating...............163
Starting.................117
Enhanced Accident Response
Feature................98, 168
Exhaust Gas Caution............112
Exhaust System...............112
Exterior Lights.............28, 114
Fabric Care..................203
Fabric Top..................203
Filters
Air Conditioning..........38, 187
Flashers
Hazard Warning.............146
Turn Signal......64, 114, 148, 149
Flash-To-Pass.................29
Flooded Engine Starting..........118
Fluid, Brake.................211
Fluid Capacities...............210
Fluid Leaks..................114
Fluid Level Checks
Brake...................183
Engine Oil................182
Manual Transmission.........184
Fluids And Lubricants...........210
INDEX
260