Limit Ram 2500 2020 Owner's Guide

230STARTING AND OPERATING
DIESEL EXHAUST BRAKE — ENGINE
BRAKING (IF EQUIPPED)
The purpose of the exhaust brake (engine
braking) feature is to supply negative (braking)
torque from the engine. Typically, the engine
braking is used for, but not limited to, vehicle
towing applications where vehicle braking can be achieved by the internal engine power,
thereby sparing the mechanical brakes of the
vehicle.
Benefits of the exhaust brake are:
Vehicle driving control.
Reduced brake fade.
Longer brake life.
Faster cab warm-up.
The exhaust brake feature will only function
when the driver toggles it on by pushing the
exhaust brake button until the “Exhaust Brake
Indicator” is illuminated. Normal (Full Strength)
exhaust brake mode is indicated by a yellow
“Exhaust Brake Indicator”.

Exhaust Brake Switch
Once the “Exhaust Brake Indicator” is illumi
-
nated and the vehicle is moving faster than
5 mph (8 km/h); the exhaust brake will auto -
matically operate when the driver removes
pressure from the accelerator pedal. Exhaust
braking is most effective when the engine RPM
is higher. The automatic transmission will down -
shift more aggressively in TOW/HAUL mode
when the exhaust brake is enabled to increase
brake performance.
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 cause 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)
WARNING!
Do not use the exhaust brake feature when
driving in icy or slippery conditions as the
increased engine braking can cause the rear
wheels to slide and the vehicle to swing
around with the possible loss of vehicle
control, which may cause an accident
possibly resulting in personal injury or death.
CAUTION!
Use of aftermarket exhaust brakes is not
recommended and could lead to engine
damage

20_DJD2_OM_EN_USC_t.book Page 230

STARTING AND OPERATING233
Eight-Speed Automatic Transmission — If
Equipped
The transmission is controlled using a rotary
electronic gear selector located on the instru -
ment panel. The transmission gear range
(PRND) is displayed both above the gear
selector and in the instrument cluster. To select
a gear range, simply rotate the gear selector.
You must press the brake pedal to shift the
transmission out of PARK (or NEUTRAL, when
the vehicle is stopped or moving at low speeds).
To shift past multiple gear ranges at once (such
as PARK to DRIVE), simply rotate the gear
selector to the appropriate detent. Select the
DRIVE range for normal driving.
NOTE:
In the event of a mismatch between the gear
selector position and the actual transmission
gear (for example, driver selects PARK while
driving), the position indicator will blink continu -
ously until the selector is returned to the proper
position, or the requested shift can be
completed.
The electronically-controlled transmission
adapts its shift schedule based on driver inputs,
along with environmental and road conditions.
The transmission electronics are self-cali -brating; therefore, the first few shifts on a new
vehicle may be somewhat abrupt. This is a
normal condition, and precision shifts will
develop within a few hundred miles (kilome
-
ters).
Only shift from DRIVE to PARK or REVERSE
when the accelerator pedal is released and the
vehicle is stopped. Be sure to keep your foot on
the brake pedal when shifting between these
gears.
The transmission gear selector has only PARK,
REVERSE, NEUTRAL, and DRIVE positions.
Manual downshifts can be made using the Elec -
tronic Range Select (ERS) shift control. Pressing
the GEAR -/GEAR + switches (on the steering
wheel) while in the DRIVE position will select the
highest available transmission gear, and will
display that gear limit in the instrument cluster
as 1, 2, 3, etc. Refer to “Electronic Range Select
(ERS) Operation” in this section for further infor -
mation. Some models will display both the
selected gear limit, and the actual current gear,
while in ERS mode.
Electronic Transmission Gear Selector

Gear Ranges
Do not depress the accelerator pedal when
shifting from PARK or NEUTRAL into another
gear range.
NOTE:
After selecting any gear range, wait a moment
to allow the selected gear to engage before
accelerating. This is especially important when
the engine is cold.
PARK (P)
This range supplements the parking brake by
locking the transmission. The engine can be
started in this range. Never attempt to use
PARK while the vehicle is in motion. Apply the
parking brake when exiting the vehicle in this
range.5

20_DJD2_OM_EN_USC_t.book Page 233

STARTING AND OPERATING235
The following indicators should be used to
ensure that you have properly engaged the
transmission into the PARK position:
Look at the transmission gear position
display and verify that it indicates the PARK
position (P), and is not blinking.
With 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 transmis
-
sion 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 provides optimum driving characteris
-
tics under all normal operating conditions.
When frequent transmission shifting occurs
(such as when operating the vehicle under
heavy loading conditions, in hilly terrain, trav -
eling into strong head winds, or while towing a
heavy trailer), select TOW/HAUL mode or use
the Electronic Range Select (ERS) shift control
refer to "Electronic Range Select [ERS] Opera -
tion" in this section for further information to
select a lower gear range. Under these condi -
tions, using a lower gear range will improve
performance and extend transmission life by
reducing excessive shifting and heat buildup.
During extremely cold temperatures (-22°F
[-30°C] or below), transmission operation may
be modified depending on engine and transmis -
sion temperature as well as vehicle speed.
Normal operation will resume once the trans -
mission temperature has risen to a suitable
level.
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 in the
ACC or ON/RUN mode. A child could
operate power windows, other controls, or
move the vehicle.
CAUTION!
DO NOT race the engine when shifting from
PARK or NEUTRAL into another gear range,
as this can damage the drivetrain.
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.
WARNING! (Continued)
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. Refer to “Recreational Towing” in
“Starting And Operating” and “Towing A
Disabled Vehicle” in “In Case Of Emergency”
for further information.
5

20_DJD2_OM_EN_USC_t.book Page 235

236STARTING AND OPERATING
Transmission Limp Home Mode
Transmission function is monitored electroni -
cally for abnormal conditions. If a condition is
detected that could result in transmission
damage, Transmission Limp Home Mode is acti -
vated. In this mode, the transmission may
operate only in certain gears, or may not shift at
all. Vehicle performance may be severely
degraded and the engine may stall. In some
situations, the transmission may not re-engage
if the engine is turned off and restarted. The
Malfunction Indicator Light (MIL) may be illumi -
nated. A message in the instrument cluster will
inform the driver of the more serious conditions,
and indicate what actions may be necessary.
In the event of a momentary problem, the trans -
mission can be reset to regain all forward gears
by performing the following steps:
NOTE:
In cases where the instrument cluster message
indicates the transmission may not re-engage
after engine shutdown, perform this procedure
only in a desired location (preferably, at an
authorized dealer).

1. Stop the vehicle.
2. Shift the transmission into PARK, if
possible. If not, shift the transmission to
NEUTRAL.
3. Push and hold the ignition switch until the engine turns off.
4. Wait approximately 30 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the problem is no longer detected, the trans -
mission will return to normal operation.
NOTE:
Even if the transmission can be reset, we
recommend that you visit an authorized dealer
at your earliest possible convenience. An autho -
rized dealer has diagnostic equipment to
assess the condition of your transmission.
If the transmission cannot be reset, authorized
dealer service is required.
Electronic Range Select (ERS) Operation
The Electronic Range Select (ERS) shift control
allows the driver to limit the highest available
gear when the transmission is in DRIVE. For
example, if you set the transmission gear limit
to 4 (FOURTH gear), the transmission will not shift above FOURTH gear (except to prevent
engine overspeed), but will shift through the
lower gears normally.
You can switch between DRIVE and ERS mode
at any vehicle speed. When the transmission
gear selector is in DRIVE, the transmission will
operate automatically, shifting between all
available gears. Tapping the GEAR – switch (on
the steering wheel) will activate ERS mode,
display the current gear in the instrument
cluster, and set that gear as the top available
gear. Once in ERS mode, tapping the GEAR – or
GEAR + switch will change the top available
gear.

ERS Control

1 — GEAR + Switch
2 — GEAR – Switch

20_DJD2_OM_EN_USC_t.book Page 236

STARTING AND OPERATING237
To exit ERS mode, simply push and hold the
GEAR + switch until the gear limit display disap -
pears from the instrument cluster.
When to Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer,
carrying a heavy load, etc., and frequent trans -
mission shifting occurs, push the TOW/HAUL
switch to activate TOW/HAUL mode. This 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 opera -
tion. 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.
Six-Speed Automatic Transmission — If
Equipped
Pickup models may use either AS69RC trans -
mission, or the 68RFE transmission (which has
no PTO access cover).
The transmission gear position display (located
in the instrument cluster) indicates the trans -
mission gear range. The gear selector is
mounted on the right side of the steering
column. You must press the brake pedal to
move the gear selector out of PARK refer to
“Brake/Transmission Shift Interlock System” in
this section. To drive, move the gear selector
from PARK or NEUTRAL to the DRIVE position.
Pull the gear selector toward you when shifting
into REVERSE or PARK, or when shifting out of
PARK.
The electronically-controlled transmission
provides a precise shift schedule. The transmis -
sion electronics are self-calibrating; therefore,
the first few shifts on a new vehicle may be
somewhat abrupt. This is a normal condition,
and precision shifts will develop within a few
hundred miles (kilometers).
Only shift from DRIVE to PARK or REVERSE
when the accelerator pedal is released and the
vehicle is stopped. Be sure to keep your foot on
WARNING!
Do not downshift for additional engine
braking 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
control, which may cause an accident
possibly resulting in personal injury or death.
5

20_DJD2_OM_EN_USC_t.book Page 237

238STARTING AND OPERATING
(Continued)
the brake pedal when shifting between these
gears.
The transmission gear selector has only PARK,
REVERSE, NEUTRAL, and DRIVE shift positions.
Manual downshifts can be made using the Elec-
tronic Range Select (ERS) shift control. Pressing
the ERS (-/+) switches (on the steering wheel)
while in the DRIVE position will select the
highest available transmission gear, and will
display that gear limit in the instrument cluster
as 1, 2, 3, etc. Refer to "Electronic Range Select
(ERS) Operation" in this section for further infor -
mation. Some models will display both the
selected gear limit, and the actual current gear,
while in ERS mode.
Gear Ranges
Do not depress the accelerator pedal when
shifting from PARK or NEUTRAL into another
gear range.
NOTE:
After selecting any gear range, wait a moment
to allow the selected gear to engage before
accelerating. This is especially important when
the engine is cold. PARK (P)
This range supplements the parking brake by
locking the transmission. The engine can be
started in this range. Never attempt to use
PARK while the vehicle is in motion. Apply the
parking brake when exiting the vehicle in this
range.
When parking on a level surface, you may shift
the transmission into PARK first, and then apply
the parking brake.
When parking on a hill, apply the parking brake
before shifting the transmission to PARK, other
-
wise the load on the transmission locking mech -
anism may make it difficult to move the gear
selector out of PARK. As an added precaution,
turn the front wheels toward the curb on a
downhill grade and away from the curb on an
uphill grade.
When exiting the vehicle, always:
Apply the parking brake.
Shift the transmission into PARK.
Turn the engine OFF.
Remove the key fob. NOTE:
On four-wheel drive vehicles be sure that the
transfer case is in a drive position.
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 movement 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 trans -
mission 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 accel -
erate 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.

20_DJD2_OM_EN_USC_t.book Page 238

240STARTING AND OPERATING
engine may be started in this range. 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 underdrive first, second, and third gears, direct fourth gear and overdrive fifth
and sixth gears. The DRIVE position provides
optimum driving characteristics under all
normal operating conditions.
When frequent transmission shifting occurs
(such as when operating the vehicle under
heavy loading conditions, in hilly terrain, trav
-
eling into strong head winds, or while towing a
heavy trailer), use the Electronic Range Select
(ERS) shift control refer to “Electronic Range
Select (ERS) Operation” in this section for
further information to select a lower gear range.
Under these conditions, using a lower gear
range will improve performance and extend
transmission life by reducing excessive shifting
and heat buildup.
If the transmission temperature exceeds
normal operating limits, the powertrain
controller will modify the transmission shift
schedule and expand the range of torque
converter clutch engagement. This is done to
prevent transmission damage due to over -
heating.
If the transmission becomes extremely hot or is
in danger of overheating, the “Transmission
Temperature Warning Light” may illuminate and
the transmission may operate differently until
the transmission cools down. NOTE:
Use caution when operating a heavily loaded
vehicle at low speeds (such as towing a trailer
up a steep grade, or in stop-and-go traffic)
during hot weather. In these conditions, torque
converter slip can impose a significant addi
-
tional heat load on the cooling system. Down -
shifting the transmission to the lowest possible
gear (when climbing a grade), or shifting to
NEUTRAL (when stopped in heavy traffic) can
help to reduce this excess heat generation.
During cold temperatures, transmission opera -
tion may be modified depending on engine and
transmission temperature as well as vehicle
speed. This feature improves warm up time of
the engine and transmission to achieve
maximum efficiency. Engagement of the torque
converter clutch is inhibited until the transmis -
sion fluid is warm refer to the “Note” under
“Torque Converter Clutch” in this section. On
Pickup models with 68RFE transmission, top
overdrive gear is also inhibited until the trans -
mission fluid is warm, and during extremely cold
temperatures (-16°F [-27°C] or below), opera -
tion may briefly be limited to first and direct
gears only. On trucks with AS69RC transmis -
sion, fifth and sixth gears may be inhibited
briefly on cold starts below 41°F (5°C), and
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. Refer to “Recreational Towing” in
“Starting And Operating” and “Towing A
Disabled Vehicle” in “In Case Of Emergency”
for further information.

20_DJD2_OM_EN_USC_t.book Page 240

STARTING AND OPERATING241
during very cold temperatures (-4°F [-20°C] or
below), operation may briefly be limited to third
gear only. During this condition, the ability of the
vehicle to accelerate under heavily loaded
conditions may be reduced. In all cases, normal
operation will resume once the transmission
temperature has risen to a suitable level.
Transmission Limp Home Mode
Transmission function is monitored electroni -
cally for abnormal conditions. If a condition is
detected that could result in transmission
damage, Transmission Limp Home Mode is acti -
vated. In this mode, the transmission remains
in fourth gear (for 68RFE transmission) or third
gear (for AS69RC transmission) regardless of
which forward gear is selected. If an
AS69RC-equipped truck enters Limp Home
Mode at highway speeds, it will initially engage
fifth gear, until the vehicle slows to a speed
where third gear can be engaged. PARK,
REVERSE, and NEUTRAL will continue to
operate. The Malfunction Indicator Light (MIL)
may be illuminated. Limp Home Mode allows
the vehicle to be driven to an authorized dealer
for service without damaging the transmission. In the event of a momentary problem, the trans
-
mission can be reset to regain all forward gears
by performing the following steps:

1. Stop the vehicle.

2. Shift the transmission into PARK.
3. Turn the ignition OFF.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the problem is no longer detected, the trans -
mission will return to normal operation.
NOTE:
Even if the transmission can be reset, we
recommend that you visit your authorized
dealer at your earliest possible convenience.
Your authorized dealer has diagnostic equip -
ment to assess the condition of your transmis -
sion.
If the transmission cannot be reset, authorized
dealer service is required.
Electronic Range Select (ERS) Operation
The Electronic Range Select (ERS) shift control
allows the driver to limit the highest available gear when the transmission is in DRIVE. For
example, if you set the transmission gear limit
to 4 (FOURTH gear), the transmission will not
shift above FOURTH gear, but will shift through
the lower gears normally.
You can switch between DRIVE and ERS mode
at any vehicle speed. When the gear selector is
in the DRIVE position, the transmission will
operate automatically, shifting between all
available gears. Tapping the ERS (-) switch will
activate ERS mode, display the current gear in
the instrument cluster, and set that gear as the
top available gear. Once in ERS mode, tapping
the ERS (-) or (+) switch will change the top
available gear.

Electronic Range Select
1 — GEAR + Switch
2 — GEAR – Switch
5

20_DJD2_OM_EN_USC_t.book Page 241

242STARTING AND OPERATING
To exit ERS mode, simply push and hold the ERS
(+) switch until the gear limit display disappears
from the instrument cluster.
NOTE:
To select the proper gear position for maximum
deceleration (engine braking), simply push and
hold the ERS (-) switch. The transmission will
shift to the range from which the vehicle can
best be slowed down.
Overdrive Operation
The automatic transmission includes an elec -
tronically controlled Overdrive (fifth and sixth
gears). The transmission will automatically shift
into Overdrive if the following conditions are
present:
The gear selector is in the DRIVE position.
The transmission fluid has reached an
adequate temperature.
The engine coolant has reached an adequate
temperature.
The vehicle speed is sufficiently high.
The driver is not heavily pressing the acceler -
ator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer,
carrying a heavy load, etc., and frequent trans -
mission shifting occurs, push the TOW/HAUL switch to activate TOW/HAUL mode. This will
improve performance and reduce the potential
for transmission overheating or failure due to
excessive shifting. When operating in TOW/
HAUL mode, transmission upshifts are delayed,
and the transmission will automatically down
-
shift (for engine braking) when the throttle is
closed and/or during steady braking maneu -
vers.

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 opera -
tion. 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.
WARNING!
Do not downshift for additional engine
braking on a slippery surface. The drive
wheels could lose their grip and the vehicle
could skid, causing a collision or personal
injury.
Transmis -
sion Gear
Limit Dis -
play 1 2 3 4 5 6 D
Actual
Gear(s)
Allowed
1 1-2 1-3 1-4 1-5 1-6 1-6
CAUTION!
When using ERS for engine braking while
descending steep grades, be careful not to
overspeed the engine. Apply the brakes as
needed to prevent engine overspeed.

20_DJD2_OM_EN_USC_t.book Page 242

252STARTING AND OPERATING
(Continued)
NOTE:
The LED will continuously blink until vehicle
Alternate Trailer Height (ATH) has been
achieved and the LED will turn on.
Pushing the Alternate Trailer Height (ATH) again
will raise the vehicle to Normal Ride Height
(NRH).
NOTE:
The LED will continuously blink until Normal
Ride Height (NRH) has been achieved and the
LED will turn off.
Transport Mode – No indicator lamps will be
illuminated. Transport Mode is disabled by
driving the vehicle, or deselecting the mode
via the interface.
Tire/Jack Mode – No indicator lamps will be
illuminated. Tire/Jack Mode is disabled by
driving the vehicle, or by deselecting the
mode via the interface.
Wheel Alignment Mode – No indicator lamps
will be illuminated. Wheel Alignment Mode is
disabled by driving the vehicle, or by dese-
lecting the mode via the interface.
Bed Lowering Mode – Telltale on the cluster
will be illuminated. Bed Lowering Mode is
disabled by driving the vehicle, or deselecting
the mode via the interface.
AXLE LOCKER SYSTEM — POWER WAGON
MODELS ONLY (IF EQUIPPED)
This vehicle is equipped with electronically
locking front and rear differentials. These differ -
entials, when engaged, mechanically lock
together the axle shafts forcing the wheels to
spin at an equal rate. This allows the vehicle to
maintain its momentum and prevents it from
becoming stuck. The locking front and rear
differentials should only be engaged during
low-speed, extreme off-road situations where
one wheel is likely to not be in contact with the
ground. It is not recommended to drive the
vehicle with the differentials locked on pave -
ment due to the reduced ability to turn and
speed limitations.
Axle Lock Selector

1 — FRONT/REAR LOCK – the front and rear axles
are locked
2 — REAR LOCK – the rear axle is locked
3 — AXLE UNLOCK – the front and rear axles are
unlocked
CAUTION!
Do not lock the front or rear axle on hard
surfaced roads. The ability to steer the
vehicle is reduced and damage to the drive
-
train may occur when the axles are locked
on hard surfaced roads.

20_DJD2_OM_EN_USC_t.book Page 252