2021 RAM 1500 warning light

146STARTING AND OPERATING
(Continued)
COLD WEATHER OPERATION (BELOW
–22°F O
R −30°C)
To ensure reliable starting at these
temperatures, use of an externally powered
electric engine block heater (available from an
authorized dealer) is recommended.
AFTER STARTING
The idle speed is controlled automatically, and
it will decrease as the engine warms up.
STARTING FLUIDS — DIESEL ENGINE
O
NLY
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:
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 wireless ignition node is in the
“OFF” mode, 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 children to be in a vehicle unat -
tended 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 chil-
dren, and do not leave the ignition of a
vehicle equipped with Keyless Enter-N-Go
in the ACC or ON/RUN mode. A child could
operate power windows, other controls, or
move the vehicle.
WARNING! (Continued)

21_DT_OM_EN_USC_t.book Page 146

STARTING AND OPERATING149
NOTE:
Under certain conditions the engine fan will run
after the engine is turned off. These conditions
are under high load and high temperature
conditions.
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. A chime will
sound when the light turns on. 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. Some important observations 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
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
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

21_DT_OM_EN_USC_t.book Page 149

152STARTING AND OPERATING
(Continued)
NOTE:
The EPB fault light will illuminate if the EPB
switch is held for longer than 20 seconds in
either the released or applied position. The light
will extinguish upon releasing the switch.
If the Auto Park Brake feature is enabled, the
parking brake will automatically engage
whenever the transmission is placed into PARK.
If your foot is on the brake pedal, you may notice
a small amount of brake pedal movement while
the parking brake is engaging.
The parking brake will release automatically
when the ignition is ON, the transmission is in
DRIVE or REVERSE, the driver seat belt is
buckled, and an attempt is made to drive away.
To release the parking brake manually, the
ignition switch must be in the ON/RUN mode.
Put your foot on the brake pedal, then push the
parking brake switch down momentarily. You
may hear a slight whirring sound from the back
of the vehicle while the parking brake
disengages. You may also notice a small
amount of movement in the brake pedal. Once
the parking brake is fully disengaged, The
BRAKE telltale light in the instrument cluster
and the LED indicator on the switch will
extinguish.NOTE:
When parking on a hill, it is important to turn the
front wheels toward the curb on a downhill
grade and away from the curb on an uphill
grade. Apply the parking brake before placing
the gear selector in PARK, otherwise the load on
the transmission locking mechanism may make
it difficult to move the gear selector out of PARK.
WARNING!
Never use the PARK position as a substi
-
tute for the parking brake. Always apply the
parking brake fully when parked to guard
against vehicle movement and possible
injury or damage.
When exiting the vehicle, always remove
the key fob from the ignition and lock your
vehicle.
Never leave children alone in a vehicle, or
with access to an unlocked vehicle.
Allowing children to be in a vehicle unat -
tended 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 chil -
dren, and do not leave a vehicle equipped
with Keyless Enter-N-Go in the ACC or ON/
RUN mode. A child could operate power
windows, other controls, or move the
vehicle.
Be sure the parking brake is fully disen -
gaged before driving; failure to do so can
lead to brake failure and a collision.
Always fully apply the parking brake when
leaving your vehicle, or it may roll and
cause damage or injury. Also be certain to
leave the transmission in PARK. Failure to
do so may allow the vehicle to roll and
cause damage or injury.
CAUTION!
If the Brake System Warning Light remains on
with the parking brake released, a brake
system malfunction is indicated. Have the
brake system serviced by an authorized
dealer immediately.
WARNING! (Continued)

21_DT_OM_EN_USC_t.book Page 152

STARTING AND OPERATING153
If exceptional circumstances should make it
necessary to engage the parking brake while
the vehicle is in motion, maintain upward
pressure on the EPB switch for as long as
engagement is desired. The BRAKE telltale light
will illuminate, and a continuous chime will
sound. The rear stop lamps will also be
illuminated automatically while the vehicle
remains in motion.
To disengage the parking brake while the
vehicle is in motion, release the switch. If the
vehicle is brought to a complete stop using the
parking brake, when the vehicle reaches
approximately 3 mph, (5 km/h) the parking
brake will remain engaged. In the unlikely event of a malfunction of the EPB
system, a yellow EPB fault light will illuminate.
This may be accompanied by the BRAKE telltale
light flashing. In this event, urgent service of the
EPB system is required. Do not rely on the
parking brake to hold the vehicle stationary.
Auto Park Brake
The Electric Park Brake (EPB) can be
programmed to be applied automatically
whenever the vehicle is at a standstill and the
automatic transmission is placed in PARK. Auto
Park Brake is enabled and disabled by
customer selection through the customer
programmable features section of the Uconnect
Settings Ú
page 245.
Any single Auto Park Brake application can be
bypassed by pushing the EPB switch to the
release position while the transmission is
placed in PARK.
SafeHold
SafeHold is a safety feature of the Electric Park
Brake (EPB) system that will engage the parking
brake automatically if the vehicle is left
unsecured while the ignition is in ON/RUN. The parking brake will automatically engage if
all of the following conditions are met:
The vehicle is at a standstill.
There is no attempt to press the brake pedal
and accelerator pedal.
The seat belt is unbuckled.
The driver door is open.
SafeHold can be temporarily bypassed by
pushing the EPB switch while the driver door is
open. Once manually bypassed, SafeHold will
be enabled again once the vehicle reaches
12 mph (20 km/h) or the ignition is turned to
the OFF position and back to ON again.
Brake Service Mode
We recommend having your brakes serviced by
an authorized dealer. You should only make
repairs for which you have the knowledge and
the right equipment. You should only enter
Brake Service Mode during brake service.
When servicing your rear brakes, it may be
necessary for you or your technician to push the
rear piston into the rear caliper bore. With the
Electric Park Brake (EPB) system, this can only
be done after retracting the EPB actuator.
WARNING!
Driving the vehicle with the parking brake
engaged, or repeated use of the parking
brake to slow the vehicle may cause serious
damage to the brake system. Be sure the
parking brake is fully disengaged before
driving; failure to do so can lead to brake
failure and a collision.
4

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160STARTING AND OPERATING

Electronic Range Select (ERS)

To exit ERS mode, simply push and hold the +
button until the gear limit display disappears
from the instrument cluster.
When to Use TOW/HAUL Mode
Select TOW/HAUL mode when driving in
conditions such as: driving in hilly areas, towing
a trailer, carrying a heavy load, etc. This mode
will improve performance and reduce the
potential for transmission overheating or failure
due to excessive shifting.

TOW/HAUL Switch
The “TOW/HAUL Indicator Light” will illuminate
in the instrument cluster to indicate that TOW/
HAUL mode has been activated. Pushing the
switch a second time restores normal
operation. Normal operation is always the
default at engine start-up. If TOW/HAUL mode is
desired, the switch must be pushed each time
the engine is started.
1 — Shift Up (+)
2 — Shift Down (–)
WARNING!
Do not downshift for additional engine brak
-
ing on a slippery surface. The drive wheels
could lose their grip and the vehicle could
skid, causing a collision or personal injury.
WARNING!
Do not use the “TOW/HAUL” feature when
driving in icy or slippery conditions. The
increased engine braking can cause the rear
wheels to slide, and the vehicle to swing
around with the possible loss of vehicle con -
trol, which may cause an accident possibly
resulting in personal injury or death.

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162STARTING AND OPERATING
NOTE:
The 4WD High and 4WD Low positions are
designed for loose, slippery road surfaces
only. Driving in the 4WD High and 4WD Low
positions on dry, hard surfaced roads may
cause increased tire wear and damage to the
driveline components.
The transfer case N (Neutral) button is located
in the center of the 4WD Control Switch and is
pushed by using a ballpoint pen or similar
object. The transfer case N (Neutral) position
is to be used for recreational towing only
Úpage 231.
Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights
(4WD High and 4WD Low) are located in the
instrument cluster and indicate the current and
desired transfer case selection. When you
select a different transfer case position, the
indicator lights will do the following:

1. The current position indicator light will turn off.

2. The selected position indicator light will flash until the transfer case completes the
shift. 3. When the shift is complete, the indicator
light for the selected position will stop
flashing and remain on.
If the transfer case does not shift into the
desired position, one or more of the following
events may occur:

1. The indicator light for the current position will remain on.

2. The newly selected position indicator light will continue to flash.
3. If the transfer case will not shift, a message
will appear on the cluster stating the 4WD
shift has canceled.
NOTE:
Before retrying a selection, make certain that all
the necessary requirements for selecting a new
transfer case position have been met. To retry
the selection, push the current position, wait
five seconds, and retry selection.
The “SVC 4WD Warning Light” monitors the
electronic shift four-wheel drive system. If this
light remains on after engine start up or
illuminates during driving, it means that the
four-wheel drive system is not functioning
properly and that service is required. NOTE:
Do not attempt to make a shift while only the
front or rear wheels are spinning. This could
cause damage to driveline components.
When operating your vehicle in 4WD Low, the
engine speed is approximately three times that
of the 2WD or 4WD High positions at a given
road speed. Take care not to overspeed the
engine and do not exceed 25 mph (40 km/h).
Proper operation of four-wheel drive vehicles
depends on tires of equal size, type and
circumference on each wheel. Any difference in
tire size can cause damage to the drivetrain.
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.
WARNING!
Always engage the parking brake when
powering down the vehicle if the “SVC 4WD
Warning Light” is illuminated. Not engaging
the parking brake may allow the vehicle to roll
which may cause personal injury or death.

21_DT_OM_EN_USC_t.book Page 162

164STARTING AND OPERATING
NOTE:
The 4WD High and 4WD Low positions are
designed for loose, slippery road surfaces
only. Driving in the 4WD High and 4WD Low positions on dry hard surfaced roads may
cause increased tire wear and damage to the
driveline components.
The transfer case N (Neutral) button is
located in the center of the 4WD Control
Switch and is pushed by using a ballpoint pen
or similar object. The transfer case N
(Neutral) position is to be used for recre
-
ational towing only Ú page 231.
Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights
(4WD High, 4WD Low, and 4WD Auto) are
located in the instrument cluster and indicate
the current and desired transfer case selection.
When you select a different transfer case
position, the indicator lights will do the
following:

1. The current position indicator light will turn off.

2. The selected position indicator light will flash until the transfer case completes the
shift.
3. When the shift is complete, the indicator light for the selected position will stop
flashing and remain on. If the transfer case does not shift into the
desired position, one or more of the following
events may occur:

1. The indicator light for the current position
will remain on.

2. The newly selected position indicator light will continue to flash.
3. If the transfer case will not shift, there will
be a cluster message stating the 4WD shift
has canceled.
NOTE:
Before retrying a selection, make certain that all
the necessary requirements for selecting a new
transfer case position have been met. To retry
the selection, push the current position, wait
five seconds, and retry selection.
The “SVC 4WD Warning Light” monitors the
electronic shift four-wheel drive system. If this
light remains on after engine start up or
illuminates during driving, it means that the
four-wheel drive system is not functioning
properly and that service is required.
WARNING!
You or others could be injured or killed if
you leave the vehicle unattended with the
transfer case in the N (Neutral) position
without first fully engaging the parking
brake. The transfer case N (Neutral) posi -
tion disengages both the front and rear
drive shaft from the powertrain, and will
allow the vehicle to roll, even if the trans -
mission is in PARK. The parking brake
should always be applied when the driver is
not in the vehicle.
The transmission may not engage PARK if
the vehicle is moving. Always bring the
vehicle to a complete stop before shifting to
PARK, and verify that the transmission gear
position indicator solidly indicates PARK (P)
without blinking. Ensure that the vehicle is
completely stopped, and the PARK position
is properly indicated, before exiting the
vehicle.

21_DT_OM_EN_USC_t.book Page 164

STARTING AND OPERATING165
NOTE:
Do not attempt to make a shift while only the
front or rear wheels are spinning. This could
cause damage to driveline components.
When operating your vehicle in 4WD Low, the
engine speed is approximately three times that
of the 2WD, 4WD Auto or 4WD High positions
at a given road speed. Take care not to
overspeed the engine and do not exceed
25 mph (40 km/h).
Proper operation of four-wheel drive vehicles
depends on tires of equal size, type and
circumference on each wheel. Any difference in
tire size can cause damage to the drivetrain.
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 Procedure
If any of the requirements to select a new
transfer case position have not been met,
then the transfer case will not shift. The posi -
tion indicator light for the previous position
will remain on and the newly selected posi -
tion indicator light will continue to flash until
all the requirements for the selected position
have been met.
If all the requirements to select a new
transfer case position have been met, then
the current position indicator light will turn off
and the selected position indicator light will
flash until the transfer case completes the
shift. When the shift is complete, the position
indicator light for the selected position will
stop flashing and remain on.
ACTIVE-LEVEL FOUR CORNER AIR
SUSPENSION SYSTEM — IF EQUIPPED
DESCRIPTION
The air suspension system provides full time
load leveling capability along with the benefit of
being able to adjust vehicle height by using the
toggle switch.
Air Suspension Switch

Normal Ride Height (NRH)
– This is the stan-
dard position of the suspension and is meant
for normal driving.

Off-Road 1 (OR1) (Raises the vehicle
approximately 1 inch (26 mm)) – This posi-
tion should be the primary position for all
off-road driving until Off-Road 2 (OR2) is
needed. A smoother and more comfortable
ride will result. To enter OR1, push the

WARNING!
Always engage the parking brake when
powering down the vehicle if the “SVC 4WD
Warning Light” is illuminated. Not engaging
the parking brake may allow the vehicle to roll
which may cause personal injury or death.
1 — Off-Road 2 Indicator (Customer Selectable)
2 — Off-Road 1 Indicator (Customer Selectable)
3 — Normal Ride Height Indicator (Customer Se -
lectable)
4 — Aero Mode Indicator (Customer Selectable)
5 — Entry/Exit Mode Indicator (Customer Select -
able)
4

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