service Ram 2500 2020 Workshop Manual

STARTING AND OPERATING227
Up Steep Hills — Select a lower transmission
gear.
Air Conditioning — Turn it off temporarily.
Do Not Operate The Engine With Low Oil
Pressure
When the engine is at normal operating
temperature, the minimum oil pressures
required are:
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 perfor -
mance, 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 oper -
ating range, in the engine operating tempera -
ture.
Excessive smoke.
Oil pressure drop.
ENGINE BLOCK HEATER — GAS ENGINE (IF
EQUIPPED)
The engine block heater warms the engine, and
permits quicker starts in cold weather. Connect
the cord to a standard 110-115 Volt AC elec -
trical outlet with a grounded, three-wire exten -
sion cord.
The engine block heater cord is routed through
the grille by the right front tow hook.
It includes a removable cap that is secured by a
tethered strap. It also has a c-clip that is used
for storage when not in use for the winter
months. During winter months, remove the
heater cord wiring assembly from itself on the
c-clip. The engine block heater must be plugged in at
least one hour to have an adequate warming
effect on the engine.
ENGINE BLOCK HEATER — DIESEL ENGINE
(IF EQUIPPED)
The engine block heater warms engine coolant
and permits quicker starts in cold weather.
Connect the heater cord to a ground-fault inter
-
rupter protected 110–115 Volt AC electrical
outlet with a grounded, three-wire extension
cord.
The engine block heater cord is routed under
the hood to the right side and can be located
just behind the grille near the headlamp.
NOTE:
The engine block heater cord is a factory
installed option. If your vehicle is not equipped,
heater cords are available from an authorized
Mopar dealer.
Idle 700 to 800 RPM 10 psi (69 kPa)
Full speed and load 30 psi (207 kPa)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.
WARNING!
Remember to disconnect the engine block
heater cord before driving. Damage to the
110-115 Volt electrical cord could cause
electrocution.
5

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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

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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

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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
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246STARTING AND OPERATING
The “SVC 4WD Warning Light” monitors the
electronic shift four-wheel drive system. If this
light remains on after engine start up or illumi -
nates during driving, it means that the
four-wheel drive system is not functioning prop -
erly 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 circum -
ference 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
NOTE:
If any of the requirements to select a new
transfer case position have not been met, the
transfer case will not shift. The position indi
-
cator light for the previous position will
remain on and the newly selected position
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, the
current position indicator light will turn off,
the selected position indicator light will flash
until the transfer case completes the shift.
When the shift is complete, the position indi -
cator light for the selected position will stop
flashing and remain on. 2WD To 4WD HIGH
Push the desired position on the 4WD control
switch to shift the transfercase. Shifts between
2WD and 4WD HIGH can be done with the
vehicle stopped or in motion. With the vehicle in
motion, the transfer case will engage/disen
-
gage faster if you momentarily release the
accelerator pedal after turning the control
switch. If the vehicle is stopped, the ignition
switch must be in the ON position with the
engine either running or off. This shift cannot be
completed if the ignition switch is in the ACC
position.
NOTE:
The four-wheel drive system will not allow shifts
between 2WD/4WD HIGH if the front and/or
rear wheels are spinning (no traction). In this
situation, the selected position indicator light
will flash and the original position indicator light
will remain on. At this time, reduce speed and
stop spinning the wheels to complete the shift.
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.

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250STARTING AND OPERATING
Transfer Case Position Indicator Light
The “Transfer Case Position Indicator Light” in
the instrument cluster is used to alert the driver
that the front axle is fully engaged and all four
wheels are driving.
AIR SUSPENSION SYSTEM — IF EQUIPPED
Description
This air suspension system is a rear leveling ride
height system. The main purpose of this system
is to maintain the truck’s rear ride height level.
There are two selectable heights that can be
chosen based on your operating conditions.
The system requires that the ignition be in the
ON/RUN position or the engine running with
zero vehicle speed for all user requested
changes and load leveling.
Rear Leveling Ride Height Switch

Normal Ride Height (NRH) – This is the standard
position of the suspension and is meant for
normal driving. It will automatically adjust to
maintain the rear ride height as conditions
change.
Alternate Trailer Height (ATH) – Lowers the
vehicle approximately 1 inch (25 mm) for a level
truck, to be used as required while trailer
towing. It will automatically adjust to maintain
the rear ride height as conditions change.
Trailer Decoupling/Unloading - The air suspen-
sion system will continue to load level after the
vehicle has been turned off for 10 minutes
without compressor activation. This allows for
easy removal of a trailer and/or load from the
back of the truck by maintaining the ride height.
After 10 minutes you will need to turn the igni -tion to the run position for the air suspension to
re-level due to addition/removal of load in the
vehicle. If the air suspension system is disabled
using the settings menu (Tire Jack Mode, Trans
-
port Mode, Alignment Mode, or Bed Lowering
Mode) the system will remain disabled when
the vehicle is turned off. Reactivating the air
suspension can be accomplished via the
settings menu or driving the vehicle above
5 mph (8 km/h) for Tire Jack Mode, Alignment
Mode, Transport Mode and Bed Lowering
Mode.
NOTE:
Most 3500 models will not lower to Alternate
Trailer Height (ATH) when unloaded.
Refer to “Trailer Towing” in “Starting And
Operating” for further information.
WARNING!
The air suspension system uses a high
pressure volume of air to operate the system.
To avoid personal injury or damage to the
system, see your authorized dealer for
service.

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STARTING AND OPERATING251
Air Suspension Modes
The air suspension system has multiple modes
to protect the system in unique situations:
Tire/Jack Mode
To assist with changing a tire, the air suspen -
sion system has a feature which allows the
automatic leveling to be disabled. This mode is
intended to be enabled with the engine running.
Refer to “Instrument Cluster Display” in
“Getting To Know Your Instrument Panel” or
“Uconnect Settings” in “Multimedia” (if
equipped with a touch screen radio) for further
information.
NOTE:
This mode is intended to be enabled with the
engine running.
Transport Mode
For towing your vehicle with four wheels off the
road, the air suspension system has a feature
which will put the vehicle below Normal Ride
Height (NRH) and disable the automatic load
leveling system. This mode is intended to be
enabled with engine running. Refer to “Instru -
ment Cluster Display” in “Getting To Know Your
Instrument Panel” or “Uconnect Settings” in
“Understanding Your Instrument Panel” if equipped with a touch screen radio for further
information.
NOTE:
This mode is intended to be enabled with the
engine running.
Wheel Alignment Mode
Before performing a wheel alignment this mode
must be enabled. Refer to “Instrument Cluster
Display” in “Getting To Know Your Instrument
Panel” or “Uconnect Settings” in “Multimedia”
(if equipped with a touch screen radio) for
further information.
NOTE:
This mode is intended to be enabled with the
engine running.
Bed Lowering Mode
This setting is used to lower the rear suspension
to the lowest possible height and disable the air
suspension system. It enables easier loading/
unloading of the truck and makes it easier to
hook up trailers. Refer to “Instrument Cluster
Display” in “Getting To Know Your Instrument
Panel” or “Uconnect Settings” in “Under
-
standing Your Instrument Panel” if equipped with a touch screen radio for further informa
-
tion.
Protection Strategy
In order to “protect” the air suspension system,
the vehicle will disable load leveling as required
(suspension overloaded, battery charge low,
etc.). Load leveling will automatically resume as
soon as system operation requirements are
met. See your authorized dealer if system does
not resume.
Instrument Cluster Display Messages
When the appropriate conditions exist, a
message will appear in the instrument cluster
display. Refer to “Instrument Cluster Display” in
“Getting To Know Your Instrument Panel” for
further information.
An audible chime will be heard whenever a
system error has been detected.
See your authorized dealer for system service if
normal operation does not resume.
Operation
Pushing the Alternate Trailer Height (ATH)
button once while at Normal Ride Height (NRH),
will lower the vehicle to Alternate Trailer Height
(ATH) and will illuminate the LED.
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254STARTING AND OPERATING
advantage to increasing ride height is the posi -
tive effect it has on approach/departure and
break over angles.
This system is controlled by the electronic
control sway bar switch located below the
instrument panel.

Sway Bar Disconnect Button

Push the SWAY BAR switch to activate the
system. Push the switch again to deactivate the
system. The “Sway Bar Indicator Light” (located
in the instrument cluster) will illuminate when
the bar is disconnected. The “Sway Bar Indi -
cator Light” will flash during activation transi -
tion, or when activation conditions are not met.
The stabilizer/sway bar should remain in
on-road mode during normal driving conditions. To disconnect the stabilizer/sway bar, shift to
either 4WD HIGH or 4WD LOW and push the
SWAY BAR button to obtain the Off-Road posi
-
tion. Refer to “Four Wheel Drive Operation” in
“Starting And Operating” for further informa -
tion. The “Sway Bar Indicator Light” will flash
until the stabilizer/sway bar has been fully
disconnected. NOTE:
The stabilizer/sway bar may be torque locked
due to left and right suspension height differ
-
ences. This condition is due to driving surface
differences or vehicle loading. In order for the
stabilizer/sway bar to disconnect/reconnect,
the right and left halves of the bar must be
aligned. This alignment may require that the
vehicle be driven onto level ground or rocked
from side to side.
To return to the On-Road mode, push the SWAY
BAR button again.WARNING!
Do not disconnect the stabilizer bar and drive
on hard surfaced roads or at speeds above
18 mph (29 km/h), you may lose control of
the vehicle, which could result in serious
injury or death. The front stabilizer bar
enhances vehicle stability and assists in
maintaining control of the vehicle. The system
monitors vehicle speed and will attempt to
reconnect the stabilizer bar at speeds over
18 mph (29 km/h). This is indicated by a
flashing off road light and solid on road light.
Once vehicle speed is reduced below 14 mph
(22 km/h), the system will attempt to return
to the Off-Road mode.
WARNING!
If the stabilizer/sway bar will not return to
On-Road mode, vehicle stability is reduced.
Do not attempt to drive the vehicle over
18 mph (29 km/h). Driving faster than
18 mph (29 km/h) may cause loss of control
of the vehicle, which could result in serious
injury or death. Contact your local service
center for assistance.

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STARTING AND OPERATING255
SAFE OFF-ROAD DRIVING — POWER
WAGON ONLY
Off-Road Driving Tips And Vehicle
Characteristics
Your vehicle has excellent on and off-road capa-
bilities. These off-road capabilities will allow you
to explore those wilderness trails where few
travel, providing a source of exciting and satis -
fying recreation. Before you venture out, you
should contact your local governmental agency
to determine the designated Off-Road Vehicle
(ORV) trails or recreation areas. You should
always tread lightly and only use established
roads, trails or ORV recreational areas.
The National Forest Service, Bureau of Land
Management, or local Department of Natural
Resources are a wealth of information and
usually have maps with marked trails.
Skid Plates And Underbody Protection
Steel skid plates protect the major driveline
components of the truck including the fuel tank,
transfer case and steering damper. In addition,
this vehicle is equipped with boxed cross
members and fore/aft rails. This additional
protection allows the vehicle to be utilized in severe off-road situations that would be consid
-
ered impassable by a normal truck.
Ramp Travel Index (RTI)
The RTI is the distance, in inches, that you can
drive your vehicle with one wheel on a
20-degree ramp without lifting any other wheel
off the ground. This distance up the ramp
divided by the wheelbase of the vehicle and
multiplied by 1,000 is the RTI. This vehicle has
an RTI of 429 (connected sway bar) or an RTI of
538 (disconnected sway bar), which means you
can articulate one front wheel 22 inches
(56 cm) or 27.5 inches (70cm) in the air while
the other three wheels remain in contact with
the ground.
Water Fording Characteristics
Water fording characteristic is the vehicle's
ability to cross a body of still water, where the
powertrain and drivetrain are safe from water
ingestion. This vehicle has high water fording
characteristics with the ability to cross a pool of
water, without stopping, 24 inches (60 cm) deep
at a maximum speed of 10 mph (16 km/h) and a
pool of water 30 inches (76 cm) deep at a maximum speed of 5 mph (8 km/h), both with an
entrance ramp angle of 1.3 degrees.
Simultaneous Brake And Throttle Operation
Many off-road driving conditions require the
simultaneous use of the brake and throttle (two
footed driving). When climbing rocks, logs, or
other stepped objects, using light brake pres
-
sure with light throttle will keep the vehicle from
jerking or lurching. This technique is also used
when you need to stop and restart a vehicle on
a steep incline.
The Basics Of Off-Road Driving
You will encounter many types of terrain driving
off-road. You should be familiar with the terrain
and area before proceeding. There are many
types of surface conditions: hard packed dirt,
gravel, rocks, grass, sand, mud, snow and ice.
Every surface has a different effect on your
vehicle's steering, handling and traction.
Controlling your vehicle is one of the keys to
successful off-road driving, so always keep a
CAUTION!
The door sill height is 25 inches (63.5 cm).
Water may intrude into the interior of the
vehicle at greater depths.
5

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264STARTING AND OPERATING
Check threaded fasteners for looseness,
particularly on the chassis, drivetrain compo -
nents, steering, and suspension. Retighten
them, if required, and torque to the values
specified in the Service Manual.
Check for accumulations of plants or brush.
These things could be a fire hazard. They
might hide damage to fuel lines, brake hoses,
axle pinion seals, and propeller shafts.
After extended operation in mud, sand,
water, or similar dirty conditions, have the
radiator, fan, brake rotors, wheels, brake
linings, and axle yokes inspected and
cleaned as soon as possible.
If you experience unusual vibration after
driving in mud, slush or similar conditions,
check the wheels for impacted material.
Impacted material can cause a wheel imbal-
ance and freeing the wheels of it will correct
the situation.
LIMITED-SLIP DIFFERENTIAL
The limited-slip differential provides additional
traction on snow, ice, mud, sand and gravel,
particularly when there is a difference between
the traction characteristics of the surface under
the right and left rear wheels. During normal
driving and cornering, the limited-slip unit
performs similarly to a conventional differential.
On slippery surfaces, however, the differential
delivers more of the driving effort to the rear
wheel having the better traction.
The limited-slip differential is especially helpful
during slippery driving conditions. With both
rear wheels on a slippery surface, a slight appli -
cation of the accelerator will supply maximum
traction. When starting with only one rear wheel
on an excessively slippery surface, slight
momentary application of the parking brake
may be necessary to gain maximum traction. Care should be taken to avoid sudden accelera-
tions when both rear wheels are on a slippery
surface. This could cause both rear wheels to
spin, and allow the vehicle to slide sideways on
the crowned surface of a road or in a turn.
WINCH USAGE — POWER WAGON ONLY (IF
EQUIPPED)
Things To Know Before Using Your Winch
General Winch Information
Your vehicle is equipped with an electric vehicle
recovery winch. This winch uses the electrical
power from the vehicle charging system to
power a motor that winds the winch rope onto
the winch drum via planetary gear reduction. By
nature, a winch is capable of generating very
high forces and should be used with care. Do
WARNING!
Abrasive material in any part of the brakes
may cause excessive wear or unpredictable
braking. You might not have full braking
power when you need it to prevent a collision.
If you have been operating your vehicle in
dirty conditions, get your brakes checked and
cleaned as necessary.
WARNING!
On vehicles equipped with a limited-slip
differential never run the engine with one rear
wheel off the ground since the vehicle may
drive through the rear wheel remaining on the
ground. You could lose control of the vehicle.

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