ECU Ram 2500 2020 Repair Manual

STARTING AND OPERATING331
RECREATIONAL TOWING (BEHIND MOTORHOME, ETC.)
Towing This Vehicle Behind Another Vehicle
NOTE:
When towing your vehicle, always follow
applicable state and provincial laws. Contact
state and provincial Highway Safety offices
for additional details.
Vehicles equipped with air suspension must
be placed in Transport mode before tying
them down (from the body) on a trailer or
flatbed truck. Refer to “Air Suspension – If
Equipped” for more information. If the
vehicle cannot be placed in Transport mode (for example, engine will not run), tie-downs
must be fastened to the axles (not to the
body). Failure to follow these instructions
may cause fault codes to be set and/or
cause loss of proper tie-down tension.Recreational Towing — Two-Wheel Drive
Models
DO NOT flat tow this vehicle. Damage to the
drivetrain will result.
Recreational towing (for two-wheel drive
models) is allowed
ONLY if the rear wheels are OFF
the ground. This may be accomplished
using a tow dolly or vehicle trailer. If using a tow
dolly, follow this procedure:
NOTE:
If vehicle is equipped with air suspension,
ensure the vehicle is set to Normal Ride Height.

1. Properly secure the dolly to the tow vehicle, following the dolly manufacturer's instruc -
tions.

2. Drive the rear wheels onto the tow dolly.
Towing Condition Wheels OFF The
Ground Two-Wheel Drive
Models Four-Wheel Drive Models
Flat Tow
NONENOT ALLOWED See Instructions
Automatic transmission in PARK
Transfer case in NEUTRAL (N)
Tow in forward direction
Dolly Tow Front
NOT ALLOWED NOT ALLOWED
Rear OK NOT ALLOWED
On Trailer ALLOK OK
5

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332STARTING AND OPERATING
(Continued)
3. Firmly apply the parking brake. Place auto-
matic transmission in PARK.
4. Properly secure the rear wheels to the dolly, following the dolly manufacturer's instruc -
tions.
5. Turn the ignition OFF and remove the key fob.
6. Install a suitable clamping device, designed for towing, to secure the front wheels in the
straight position.Recreational Towing — Four-Wheel Drive
Models
NOTE:
Both the manual shift and electronic shift
transfer cases must be shifted into NEUTRAL
(N) for recreational towing. Automatic transmis -
sions must be shifted into PARK for recreational
towing. Refer to the following for the proper
transfer case NEUTRAL (N) shifting procedure
for your vehicle.
CAUTION!
Towing with the rear wheels on the ground
will cause severe transmission damage.
Damage from improper towing is not
covered under the New Vehicle Limited
Warranty.
Do not disconnect the driveshaft because
fluid may leak from the transmission,
causing damage to internal parts.
CAUTION!
DO NOT dolly tow any 4WD vehicle. Towing
with only one set of wheels on the ground
(front or rear) will cause severe transmis -
sion and/or transfer case damage. Tow
with all four wheels either ON the ground, or
OFF the ground (using a vehicle trailer).
Tow only in the forward direction. Towing
this vehicle backwards can cause severe
damage to the transfer case.
Before recreational towing, the transfer
case must be in NEUTRAL. To be certain the
transfer case is fully in NEUTRAL, perform
the procedure outlined under “Shifting Into
NEUTRAL”. Internal transmission damage
will result, if the transfer case is not in
NEUTRAL during towing.
The transmission must be placed in PARK
for recreational towing.
Towing this vehicle in violation of the above
requirements can cause severe transmis -
sion and/or transfer case damage.
Damage from improper towing is not
covered under the New Vehicle Limited
Warranty.
Do not disconnect the rear driveshaft
because fluid will leak from the transfer
case, causing damage to internal parts.
Do not use a bumper-mounted clamp-on
tow bar on your vehicle. The bumper face
bar will be damaged.
CAUTION! (Continued)

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IN CASE OF EMERGENCY347
(Continued)
Jacking Instructions

Jack Warning Label Lug Wrench Adapter Shown In Jack And Tools Assembly

1. Remove the spare wheel, jack, and tools
from storage.

2. Using the lug wrench, loosen, but do not remove, the wheel nuts by turning them
counterclockwise one turn while the wheel
is still on the ground. Changing a dually tire
requires the lug wrench adapter.
WARNING!
Carefully follow these tire changing warnings
to help prevent personal injury or damage to
your vehicle:
Always park on a firm, level surface as far
from the edge of the roadway as possible
before raising the vehicle.
Turn on the Hazard Warning Flashers.
Apply the parking brake firmly and set the
transmission in PARK.
Block the wheel diagonally opposite the
wheel to be raised.
Never start or run the engine with the
vehicle on a jack.
Do not let anyone sit in the vehicle when it
is on a jack.
Do not get under the vehicle when it is on a
jack. If you need to get under a raised
vehicle, take it to a service center where it
can be raised on a lift.
Only use the jack in the positions indicated
and for lifting this vehicle during a tire
change.
If working on or near a roadway, be
extremely careful of motor traffic.
To assure that spare tires, flat or inflated,
are securely stowed, spares must be
stowed with the valve stem facing the
ground.
WARNING! (Continued)
CAUTION!
Do not attempt to raise the vehicle by jacking
on locations other than those indicated in the
Jacking Instructions for this vehicle.
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352IN CASE OF EMERGENCY
Reinstalling The Jack And Tools

1. Tighten the jack all the way down by
turning the jack turn-screw counterclock-
wise until the jack is snug.

2. Position the jack and tools into bracket assembly. Make sure the lug wrench is
under the jack near the jack turn-screw.
Snap tools into bracket assembly clips.
Install the jack into bracket assembly and
turn the jack turn-screw clockwise until jack
is snug into bracket assembly.

Jack And Tools Bracket Assembly
3. Place the jack and tool bracket assembly in
the storage position holding the jack by the
jack turn-screw, slip the jack and tools
under the seat so that the bottom slot
engages into the fastener on the floor.

Jack Hold Down Fastener

NOTE:
Ensure that the jack and tool bracket assembly
slides into the front hold down location.
4. Turn the wing bolt clockwise to secure to the floor pan. Reinstall the plastic cover.
Wing Bolt/Jack And Tools

Hub Caps/Wheel Covers — If Equipped
The hub caps must be removed before raising
the vehicle off the ground.
CAUTION!
Use extreme caution when removing the front
and rear wheel covers. Damage can occur to
the center cap and/or the wheel if
screwdriver type tools are used. A pulling
motion, not a pry off motion, is recommended
to remove the caps.

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IN CASE OF EMERGENCY355
F0940 Amp Green (SSV &
Cummins Diesel) –
Aux Relay Output / Diesel Fuel Heater – If Equipped
F09 30 Amp Pink –Brake Vacuum Pump – If Equipped (HD Only)
F10 40 Amp Green –Body Controller / Exterior Lighting #2
F11 30 Amp Pink –PWR - Trailer Tow Electric Brake Batt Feed – If Equipped
(DS 1500 Only)
F11 40 Amp Green –Brake System Module (ECU and Valves) (HD Only)
F12 40 Amp Green –Body Controller #3
F13 40 Amp Green –Blower Motor
F14 40 Amp Green –Body Controller #4 / Exterior Lighting
F15 30 Amp Pink
40 Amp Green –
–Power Side Steps – If Equipped (HD Only)
Extra Fuse - SSV Only
F16 30 Amp Pink –Smart-Bar Module – If Equipped (HD Only)
F17 30 Amp Pink –Winch Control Module – If Equipped (HD Only)
F19 20 Amp Blue (DS 1500 LD
Diesel)
30 Amp Pink (Cummins Diesel) –
SCR – If Equipped
F20 30 Amp Pink –Passenger Door Module
F21 30 Amp Pink –Drive Train Control Module
F22 20 Amp Blue –Engine Control Module GPEC / Heavy Duty / Other – If
Equipped
Cavity
Cartridge Fuse Micro Fuse Description
6

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366IN CASE OF EMERGENCY
MANUAL PARK RELEASE — 8 – SPEED
TRANSMISSION
To push or tow the vehicle in cases where the
transmission will not shift out of PARK (such as
a depleted battery), a Manual Park Release is
available.
Manual Park Release Panel Cover
Manual Park Release Pull Strap

Follow these steps to activate the Manual Park
Release:

1. Firmly apply the parking brake.
2. Using a small screwdriver or similar tool,
remove the Manual Park Release access
cover, which is just above the parking brake
release handle, below and to the left of the
steering column.
3. Press and maintain firm pressure on the brake pedal.
4. Using the screwdriver or similar tool, push the Manual Park Release lever locking tab
(just below the middle of the lever) to the
right.
5. While holding the locking tab in the disen -
gaged position, pull the tether strap to
rotate the lever rearward, until it locks in
place pointing towards the driver's seat.
Release the locking tab and verify that the
Manual Park Release lever is locked in the
released position.
6. The vehicle is now out of PARK and can be towed. Release the parking brake only when
the vehicle is securely connected to a tow
vehicle.
WARNING!
Always secure your vehicle by fully applying
the parking brake before activating the
Manual Park Release. In addition, you should
be seated in the driver’s seat with your foot
firmly on the brake pedal when activating the
Manual Park Release. Activating the Manual
Park Release will allow your vehicle to roll
away if it is not secured by the parking brake,
or by proper connection to a tow vehicle.
Activating the Manual Park Release on an
unsecured vehicle could lead to serious injury
or death for those in or around the vehicle.

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IN CASE OF EMERGENCY367
To Reset The Manual Park Release:

1. Push the locking tab to the right, to unlock
the lever.

2. Rotate the Manual Park Release lever forward to its original position, until the
locking tab snaps into place to secure the
lever.
3. Pull gently on the tether strap to confirm that the lever is locked in its stowed posi-
tion.
4. Re-install the access cover.
IF YOUR ENGINE OVERHEATS
In any of the following situations, you can
reduce the potential for overheating by taking
the appropriate action.
On the highways — slow down.
In city traffic — while stopped, place the trans -
mission in NEUTRAL, but do not increase the
engine idle speed while preventing vehicle
motion with the brakes. NOTE:
There are steps that you can take to slow down
an impending overheat condition:
If your Air Conditioner (A/C) is on, turn it off.
The A/C system adds heat to the engine
cooling system and turning the A/C off can
help remove this heat.
You can also turn the temperature control to
maximum heat, the mode control to floor and
the blower control to high. This allows the
heater core to act as a supplement to the
radiator and aids in removing heat from the
engine cooling system.
FREEING A STUCK VEHICLE
If your vehicle becomes stuck in mud, sand, or
snow, it can often be moved using a rocking
motion. Turn the steering wheel right and left to
clear the area around the front wheels. Then
shift back and forth between DRIVE (D) and
REVERSE (R), while gently pressing the acceler
-
ator. Use the least amount of accelerator pedal
pressure that will maintain the rocking motion,
without spinning the wheels or racing the
engine.
WARNING!
You or others can be badly burned by hot
engine coolant (antifreeze) or steam from
your radiator. If you see or hear steam coming
from under the hood, do not open the hood
until the radiator has had time to cool. Never
try to open a cooling system pressure cap
when the radiator or coolant bottle is hot.
CAUTION!
Driving with a hot cooling system could
damage your vehicle. If the temperature
gauge reads HOT (H), pull over and stop the
vehicle. Idle the vehicle with the air
conditioner turned off until the pointer drops
back into the normal range. If the pointer
remains on HOT (H), and you hear continuous
chimes, turn the engine off immediately and
call for service.
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370IN CASE OF EMERGENCY
If the key fob is unavailable or the vehicle's
battery is discharged, refer to ”Manual Park
Release” in this section for instructions on
shifting the transmission out of PARK for
towing.
Two-Wheel Drive Models
The manufacturer recommends towing your
vehicle with all four wheels OFF the ground
using a flatbed.
If flatbed equipment is not available, and the
transmission is operable, the vehicle may be
towed (with rear wheels ON the ground) under
the following conditions:
The transmission must be in NEUTRAL. NOTE:
Refer to “Manual Park Release” in this section
for instructions on shifting the transmission to
NEUTRAL when the engine is OFF.
The towing speed must not exceed 30 mph
(48 km/h).
The towing distance must not exceed
30 miles (48 km) for 8–speed transmission.
The towing distance must not exceed
15 miles (24 km) for 6–speed transmission.
If the transmission is not operable, or the
vehicle must be towed faster than 30 mph
(48 km/h) or farther than 30 miles (48 km) for 8–speed transmission, tow with the rear wheels
OFF the ground. Acceptable methods are to tow
the vehicle on a flatbed, or with the front wheels
raised and the rear wheels on a towing dolly, or
(when using a suitable steering wheel stabilizer
to hold the front wheels in the straight position)
with the rear wheels raised and the front wheels
on the ground.
Four-Wheel Drive Models
The manufacturer recommends towing with all
wheels OFF the ground. Acceptable methods
are to tow the vehicle on a flatbed or with one
end of vehicle raised and the opposite end on a
towing dolly.
If flatbed equipment is not available, and the
transfer case is operable, the vehicle may be
towed (in the forward direction, with ALL wheels
on the ground), IF the transfer case is in
NEUTRAL (N) and the transmission is in PARK.
Refer to “Recreational Towing” in “Starting And
Operating” for further information and detailed
instructions.
CAUTION!
Do not use sling type equipment when
towing. Vehicle damage may occur.
When securing the vehicle to a flat bed
truck, do not attach to front or rear suspen -
sion components. Damage to your vehicle
may result from improper towing.
CAUTION!
Towing this vehicle in violation of the above
requirements can cause severe transmission
damage. Damage from improper towing is not
covered under the New Vehicle Limited
Warranty.

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400SERVICING AND MAINTENANCE
3. Remove the air cleaner filter element from
the housing assembly.

Air Cleaner Filter

Engine Air Cleaner Filter Installation
NOTE:
Inspect and clean the housing if dirt or debris is
present before replacing the air filter element.

1. Install the air cleaner filter element into the housing assembly with the air cleaner filter
inspection surface facing downward.

2. Install the air cleaner cover onto the housing assembly locating tabs. 3. Install screws to secure the air cleaner
cover to the housing assembly.
Air Conditioner Maintenance
For best possible performance, your air condi -
tioner should be checked and serviced by an
authorized dealer at the start of each warm
season. This service should include cleaning of
the condenser fins and a performance test.
Drive belt tension should also be checked at
this time.
Refrigerant Recovery And Recycling —
R-134a — (If Equipped)
R-134a Air Conditioning Refrigerant is a hydro -
fluorocarbon (HFC) that is an ozone-friendly
substance. The manufacturer recommends
that air conditioning service be performed by an
authorized dealer or other service facilities
using recovery and recycling equipment.
NOTE:
Use only manufacturer approved A/C system
PAG compressor oil and refrigerants.
Refrigerant Recovery And Recycling —
R-1234yf — (If Equipped)
R–1234yf Air Conditioning Refrigerant is a
hydrofluoroolefin (HFO) that is endorsed by the
Environmental Protection Agency and is an
ozone-friendly substance with a low
global-warming potential. The manufacturer
1 — Air Cleaner Filter
2 — Air Cleaner Filter Inspection Surface
WARNING!
Use only refrigerants and compressor lubri -
cants approved by the manufacturer for
your air conditioning system. Some unap -
proved refrigerants are flammable and can
explode, injuring you. Other unapproved
refrigerants or lubricants can cause the
system to fail, requiring costly repairs.
Refer to Warranty Information Book, for
further warranty information.
The air conditioning system contains refrig -
erant under high pressure. To avoid risk of
personal injury or damage to the system,
adding refrigerant or any repair requiring
lines to be disconnected should be done by
an experienced technician.
CAUTION!
Do not use chemical flushes in your air
conditioning system as the chemicals can
damage your air conditioning components.
Such damage is not covered by the New
Vehicle Limited Warranty.

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404SERVICING AND MAINTENANCE
If water is detected in the water separator while
the engine is running, or while the ignition
switch is in the ON position, the “Water In Fuel
Indicator Light” will illuminate and an audible
chime will be heard five times. At this point you
should stop the engine and drain the water from
both of the filters.
If the “Water In Fuel Indicator Light” comes on
and a single chime is heard while you are
driving, or with the ignition switch in the ON
position, there may be a problem with your
water separator wiring or sensor. See an autho -
rized dealer for service.
Upon proper draining of the water from both
fuel filters, the “Water In Fuel Indicator Light”
will remain illuminated for approximately 10
seconds. If the water was drained while the
engine was running, the “Water In Fuel Indicator
Light” may remain on for approximately three
minutes. NOTE:
Care should be taken in disposing of used fluids
from your vehicle. Used fluids, indiscriminately
discarded, can present a problem to the envi
-
ronment. Contact an authorized dealer, service
station, or government agency for advice on
recycling programs and for where used fluids
and filters can be properly disposed of in your
area.
Drain the fuel/water separator filters when the
“Water In Fuel Indicator Light” is ON. Within
10 minutes of vehicle shutdown, turn the
engine mounted filter drain valve (located on
the side of the filter assembly) counterclock -
wise 1/4 turn, and turn the under body
mounted filter drain valve (located on the
bottom of the filter assembly) counterclockwise
wise 1 full turn. Then turn the ignition switch to
the ON position, and allow any accumulated
water to drain. Leave the drain valve open until
all water and contaminants have been
removed. When clean fuel is visible, close the
drain valve following these guidelines:
1. Rotate the drain clockwise to close until
you feel resistance from the internal seal.

2. Continue turning the drain 1/2 of a turn to properly compress the seal.
NOTE:
Over-compression of the seal due to over-tight -
ening of the drain will damage the seal, cause a
leak, and require the entire sensor to be
replaced.
3. Turn the ignition switch to OFF.
The sensor drain should not be over-tightened
during normal service operations to avoid
internal damage and future fuel leaks. The
drain should be closed and secured without the
use of tools.
If more than a couple ounces/milliliters of fuel
have been drained, follow the directions for
“Priming If The Engine Has Run Out Of Fuel.”
CAUTION!
If the “Water In Fuel Indicator Light” remains
on, DO NOT START the engine before you
drain water from the fuel filters to avoid
engine damage.

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