2023 JEEP GLADIATOR fuel

148STARTING AND OPERATING
NOTE:Engine start-up in very low ambient temperature
could result in evident white smoke. This condition
will disappear as the engine warms up.
AUTOMATIC TRANSMISSION
Start the engine with the transmission gear
selector in the PARK (P) position. Apply the brake
before shifting to any driving range.
EXTREME COLD WEATHER
The cartridge block heater clips into the engine
block near the water jacket and transfers heat to
the coolant. It requires a 110–115 Volt AC
electrical outlet with a grounded, three-wire
extension cord. Its use is recommended for
environments that routinely fall below -10°F
(-23°C). It should be used when the vehicle has not
been running overnight or longer periods and
should be plugged in two hours prior to start. Its
use is required for cold starts with temperatures
under -20°F (-28°C).
NOTE:The engine block heater and heater cord are
factory installed options. If your vehicle is not
equipped, engine block heaters and heater cords
are available from an authorized Mopar® dealer.
A 12 Volt heater built into the fuel filter housing
aids in preventing fuel gelling. It is controlled by
a built-in thermostat.
A Diesel Pre-Heat system both improves engine
starting and reduces the amount of white
smoke generated by a warming engine.
NORMAL STARTING
Observe the instrument cluster lights when
starting the engine.
NOTE:Normal starting of either a cold or a warm engine is
obtained without pumping or pressing the accel -
erator pedal.

1. Always apply the parking brake.

2. Press and hold the brake pedal while pushing the ENGINE START/STOP button once.
NOTE:A delay of the start of up to five seconds is possible
under very cold conditions. The “Wait to Start”
telltale will be illuminated during the preheat
process. When the engine “Wait To Start” telltale
turns off the engine will automatically crank.
Do not leave the key fob in or near the vehicle,
or in a location accessible to children, and do
not leave the ignition of a vehicle equipped
with Keyless Enter ‘n Go™ in the ACC or ON/
RUN position. A child could operate power
windows, other controls, or move the vehicle.
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build-up
may cause serious injury or death.
CAUTION!
The engine is allowed to crank as long as
25 seconds. If the engine fails to start during
this period, please wait at least two minutes
for the starter to cool before repeating start
procedure.
If the Water in Fuel Indicator Light remains on,
DO NOT START engine before you drain the
water from the fuel filters to avoid engine
damage Ú page 368.
WARNING!
CAUTION!
If the Water in Fuel Indicator Light remains on,
DO NOT START the engine before you drain the
water from the fuel filters to avoid engine
damage Úpage 368.

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STARTING AND OPERATING149
(Continued)
3. The system will automatically engage the
starter to crank the engine. If the vehicle fails
to start, the starter will disengage automat-
ically after 25 seconds.
4. If you wish to stop the cranking of the engine prior to the engine starting, push the ENGINE
START/STOP button again.
5. Check that the Oil Pressure Warning Light has turned off.
6. Release the parking brake.
STARTING FLUIDS
The engine is equipped with a glow plug preheating
system. If the instructions in this manual are
followed, the engine should start in all conditions
and no type of starting fluid should be used.
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the diesel engine is
operating:
All message center lights are off.
Malfunction Indicator Light (MIL) is off.
Engine Oil Pressure telltale is not illuminated.
Voltmeter operation.
The voltmeter may show a gauge fluctuation at
various engine temperatures. This is caused by the
glow plug heating system. The number of cycles
and the length of the cycling operation is controlled by the engine control module. Glow plug heater
operation can run for several minutes. Once the
heater operation is complete the voltmeter needle
will stabilize.
COLD WEATHER PRECAUTIONS
Operation in ambient temperature below 32°F
(0°C) may require special considerations. The
following charts suggest these options:
Fuel Operating Range
NOTE:Use Ultra Low Sulfur Diesel (ULSD) Fuels
ONLY.

Fuel Operating Range Chart

*Number 1 ULSD Fuel should only be used where
extended arctic conditions 0°F (-18°C) exist.
WARNING!
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build-up
may cause serious injury or death.
When leaving the vehicle, always make sure
the keyless ignition node is in the OFF posi -
tion, remove the key fob from the vehicle and
lock the vehicle.
Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing chil -
dren to be in a vehicle unattended is
dangerous for a number of reasons. A child or
others could be seriously or fatally injured.
Children should be warned not to touch the
parking brake, brake pedal or the gear
selector.
Do not leave the key fob in or near the vehicle,
or in a location accessible to children, and do
not leave the ignition of a vehicle equipped
with Keyless Enter ‘n Go™ in the ACC or ON/
RUN position. A child could operate power
windows, other controls, or move the vehicle.
WARNING!
4

23_JT_OM_EN_USC_t.book Page 149

150STARTING AND OPERATING
NOTE:
Use of Climatized ULSD Fuel or Number 1 ULSD
fuel results in a noticeable decrease in fuel
economy.
Climatized ULSD fuel is a blend of Number 2
ULSD fuel and Number 1 ULSD fuel which
reduces the temperature at which wax crystals
form in fuel.
The fuel grade should be clearly marked on the
pump at the fuel station.
The engine requires the use of Ultra Low Sulfur
Diesel Fuel . Use of incorrect fuel could result in
engine and exhaust system damage
Ú page 421.
If climatized or Number 1 ULSD fuel is not avail -
able, and you are operating below 20°F (-6°C),
in sustained arctic conditions, Mopar®
Premium Diesel Fuel Treatment (or equivalent) is recommended to avoid gelling (see Fuel Oper
-
ating Range Chart).
Engine Oil Usage
See Engine Fluids and Lubricants for the correct
engine oil viscosity Ú page 424.
Engine Warm-Up
Avoid full throttle operation when the engine is
cold. When starting a cold engine, bring the engine
up to operating speed slowly to allow the oil
pressure to stabilize as the engine warms up.
If temperatures are below 32°F (0°C), operate the
engine at moderate speeds for five minutes before
full loads are applied.
ENGINE IDLING
Avoid prolonged idling. Long periods of idling may
be harmful to your engine because combustion chamber temperatures can drop so low that the
fuel may not burn completely. Incomplete
combustion allows carbon and varnish to form on
piston rings, cylinder head valves, turbocharger,
and injector nozzles. Also, the unburned fuel can
enter the crankcase, diluting the oil and causing
rapid wear to the engine.
STOPPING THE ENGINE
After full load operation, idle the engine for a few
minutes before shutting it down. This idle period
will allow the lubricating oil and coolant to carry
excess heat away from the turbocharger.
NOTE:Refer to the following chart for proper engine
shutdown.
Driving Condition Load Turbocharger Temperature Idle Time (min.) Before Engine
Shutdown
Stop and Go EmptyCoolNone
Stop and Go Medium 0.5
Highway Speeds MediumWarm 1.0
City Traffic Maximum GCWR 1.5
Highway Speeds Maximum GCWR 2.0
Uphill Grade Maximum GCWR Hot2.5

23_JT_OM_EN_USC_t.book Page 150

STARTING AND OPERATING151
NOTE:Under certain conditions the Stop/Start system
may be temporarily disabled and the engine fan
will run after the engine is turned off to protect the
engine. These conditions are under high load and
high temperature conditions.
COOLING SYSTEM TIPS — AUTOMATIC
T
RANSMISSION
To reduce the potential for engine and
transmission overheating in high ambient
temperature conditions, take the following actions:
City Driving — When stopped, shift the transmis -
sion into NEUTRAL (N) and increase engine idle
speed.
Highway Driving — Reduce your speed.
Up Steep Hills — Select a lower transmission
gear.
Air Conditioning — Turn it off temporarily.
NOTE:If the coolant temperature is too high, the A/C will
automatically turn off.
Do Not Operate The Engine With Low Oil
Pressure
If the Low Oil Pressure Warning Light turns on while
driving, stop the vehicle and shut down the engine
as soon as possible. After the vehicle is safely
stopped, restart the engine and monitor the lamp. If the lamp is still illuminated, shut the engine off,
contact an authorized dealer, and do not operate
the vehicle until the cause is corrected. If the lamp
is no longer illuminated, the engine can be
operated, but should be taken to an authorized
dealer as soon as possible for further inspection.
NOTE:Do not operate the vehicle until the cause is
corrected. This light does not show how much oil is
in the engine. The engine oil level must be checked
under the hood.
Do Not Operate The Engine With Failed
Parts
All engine failures give some warning before the
parts fail. Be on the alert for changes in
performance, sounds, and visual evidence that the
engine requires service. Some important clues are:
Engine misfiring or vibrating severely
Sudden loss of power
Unusual engine noises
Fuel, oil or coolant leaks
Sudden change, outside the normal operating
range, in the engine operating temperature
Excessive smoke
Oil pressure drop
ENGINE BREAK-IN RECOMMENDATIONS —
GASOLINE ENGINE (IF EQUIPPED)
A long break-in period is not required for the engine
and drivetrain (transmission and axle) in your
vehicle.
Drive moderately during the first 300 miles
(500 km). After the initial 60 miles (100 km),
speeds up to 50 or 55 mph (80 or 90 km/h) are
desirable.
While cruising, brief full-throttle acceleration within
the limits of local traffic laws contributes to a good
break-in. Wide-open throttle acceleration in low
gear can be detrimental and should be avoided.
The engine oil installed in the engine at the factory
is a high-quality energy conserving type lubricant.
Oil changes should be consistent with anticipated
climate conditions under which vehicle operations
will occur.
For the recommended viscosity and quality grades
see Ú page 424.
CAUTION!
If oil pressure falls to less than normal readings,
shut the engine off immediately. Failure to do so
could result in immediate and severe engine
damage.
4

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152STARTING AND OPERATING
NOTE:A new engine may consume some oil during its first
few thousand miles (kilometers) of operation. This
should be considered a normal part of the break-in
and not interpreted as a problem.
ENGINE BREAK-IN RECOMMENDATIONS —
DIESEL ENGINE (IF EQUIPPED)
The diesel engine does not require a break-in
period due to its construction. Normal operation is
allowed, providing the following recommendations
are followed:
Warm up the engine before placing it under
load.
Do not operate the engine at idle for prolonged
periods.
Use the appropriate transmission gear to
prevent engine lugging.
Observe vehicle oil pressure and temperature
indicators.
Check the coolant and oil levels frequently.
Vary throttle position at highway speeds when
carrying or towing significant weight.
NOTE:Light duty operation such as light trailer towing or
no load operation will extend the time before the
engine is at full efficiency. Reduced fuel economy
and power may be seen at this time.
The engine oil installed in the engine at the factory
is a high-quality energy conserving type lubricant.
Oil changes should be consistent with anticipated
climate conditions under which vehicle operations
will occur. For recommended viscosity and quality
grades Úpage 424. NON-DETERGENT OR
STRAIGHT MINERAL OILS MUST NEVER BE USED.
PARKING BRAKE
Before exiting the vehicle, make sure that the
parking brake is fully applied. Also, be certain to
leave an automatic transmission in PARK, or
manual transmission in REVERSE or FIRST gear.
The parking brake lever is located in the center
console. To apply the parking brake, pull the lever
up as firmly as possible. To release the parking
brake, pull the lever up slightly, push the center
button, then lower the lever completely.
Parking Brake Lever

When the parking brake is applied with the ignition
switch ON, the Brake Warning Light in the
instrument cluster will illuminate.
NOTE:
When the parking brake is applied and the auto -
matic transmission is placed in gear, the Brake
Warning Light will flash. If vehicle speed is
detected, a chime will sound to alert the driver.
Fully release the parking brake before
attempting to move the vehicle.
This light only shows that the parking brake is
applied. It does not show the degree of brake
application.
CAUTION!
Never use Non-Detergent Oil or Straight Mineral
Oil in the engine or damage may result.

23_JT_OM_EN_USC_t.book Page 152

154STARTING AND OPERATING
NOTE:During cold weather, you may experience
increased effort in shifting until the transmission
fluid warms up. This is normal.

Manual Transmission Shifter
To shift the gears, fully press the clutch pedal and
place the gear selector into the desired gear
position (the diagram for the engagement of the
gears is displayed on the handle of the selector).
The gear position will be displayed in the
instrument cluster.
To engage REVERSE gear from the NEUTRAL
position, lift the REVERSE ring, located below the
knob and move the gear selector all the way left
and then forward.
SHIFTING
Fully press the clutch pedal before shifting gears.
As you release the clutch pedal, lightly press the
accelerator pedal.
You should always use FIRST gear when starting
from a standing position.
NOTE:A certain amount of noise from the transmission is
normal. This noise can be most noticeable when
the vehicle is idling in NEUTRAL with the clutch
engaged (clutch pedal released), but it may also be
heard when driving. The noise may also be more
noticeable when the transmission is warm. This
noise is normal and is not an indication of a
problem with your clutch or transmission.
Recommended Vehicle Shift Speeds
To utilize your manual transmission efficiently for
both fuel economy and performance, it should be
upshifted as listed in the recommended shift
speed chart. Shift at the vehicle speeds listed for
acceleration. When heavily loaded or pulling a
trailer, these recommended up shift speeds may
not apply.
NOTE:Vehicle speeds shown in the chart above are for 2H and 4H only. Vehicle speeds in 4L would be significantly less.
Manual Transmission Shift Speeds in MPH (KM/H)
Engine
Speeds 1 to 22 to 33 to 44 to 55 to 6
3.6L Accel.
15 (24) 24 (39)50 (80)65 (104) 70 (112)
Cruise 10 (16) 19 (31)40 (64)55 (88)65 (105)

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STARTING AND OPERATING159
The following indicators should be used to ensure
that you have properly engaged the transmission
into the PARK position:
When shifting into PARK, push the lock button
on the gear selector and firmly move the gear
selector all the way forward until it stops and is
fully seated.
Look at the transmission gear position display
and verify that it indicates the PARK position (P),
and is not blinking.
With the brake pedal released, verify that the
gear selector will not move out of PARK.
REVERSE (R)
This range is for moving the vehicle backward.
Shift into REVERSE only after the vehicle has come
to a complete stop. NEUTRAL (N)
Use this range when the vehicle is standing for
prolonged periods with the engine running. Apply
the parking brake and shift the transmission into
PARK if you must exit the vehicle.
DRIVE (D)
This range should be used for most city and
highway driving. It provides the smoothest upshifts
and downshifts, and the best fuel economy. The
transmission automatically upshifts through all
forward gears. The DRIVE position should be used
for all normal operating conditions.When frequent transmission shifting occurs (such
as when operating the vehicle under heavy loading
conditions, in hilly terrain, traveling into strong
head winds, or while towing a heavy trailer), use
the AutoStick shift control to select a lower gear
Ú
page 160. Under these conditions, using a lower
gear will improve performance and extend
transmission life by reducing excessive shifting
and heat build-up.
During extremely cold temperatures (-22°F
[-30°C] or below), transmission operation may be
modified depending on engine and transmission
temperature as well as vehicle speed. Normal
operation will resume once the transmission
temperature has risen to a suitable level.
MANUAL (M)
The MANUAL (M, +/-) position (beside the DRIVE
position) enables full manual control of
transmission shifting also known as AutoStick
mode. Toggling the gear selector forward (-) or
rearward (+) while in the MANUAL (AutoStick)
position will manually select the transmission gear,
and will display the current gear in the instrument
cluster Ú page 160.
Transmission Limp Home Mode
Transmission function is monitored electronically
for abnormal conditions. If a condition is detected
that could result in transmission damage,
Transmission Limp Home mode is activated. In this
CAUTION!
Before moving the transmission gear selector
out of PARK, you must start the engine, and
also press the brake pedal. Otherwise,
damage to the gear selector could result.
DO NOT race the engine when shifting from
PARK or NEUTRAL into another gear range, as
this can damage the drivetrain.WARNING!
Do not coast in NEUTRAL and never turn off the
ignition to coast down a hill. These are unsafe
practices that limit your response to changing
traffic or road conditions. You might lose control
of the vehicle and have a collision.
CAUTION!

Towing the vehicle, coasting, or driving for any
other reason with the transmission in NEUTRAL
can cause severe transmission damage.

For Recreational Towing Ú page 205.
For Towing A Disabled Vehicle Ú page 350.
4

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164STARTING AND OPERATING
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 Ú page 164.
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
experienced due to uneven tire wear, low or
uneven tire pressures, 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.
4H PART TIME/4H AUTO TO 4L OR 4L TO 4H
PART TIME/4H AUTO
With the vehicle rolling at 1 to 3 mph (2 to 5 km/h),
shift an automatic transmission into NEUTRAL (N),
or press the clutch pedal on a manual
transmission. While the vehicle is coasting at 1 to
3 mph (2 to 5 km/h), shift the transfer case lever
firmly to the desired position. Do not pause with
the transfer case in N (Neutral). Once the shift is

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