2020 Ram 3500 Chassis Cab overheating

GETTING TO KNOW YOUR VEHICLE63
The temperature can be displayed in U.S. or
Metric units by selecting the U.S./Metric
customer-programmable feature. Refer to
the “Uconnect Settings” in “Multimedia” for
further information.
To provide you with maximum comfort in the
Automatic mode during cold start-ups, the
blower fan will remain on low until the engine
warms up. The blower will increase in speed
and transition into Auto mode.
Manual Operation Override
This system offers a full complement of manual
override features. The AUTO symbol in the front
ATC display will be turned off when the system
is being used in the manual mode.
Operating Tips
NOTE:
Refer to the chart at the end of this section for
suggested control settings for various weather
conditions.
Summer Operation
The engine cooling system must be protected
with a high-quality antifreeze coolant to provide
proper corrosion protection and to protect
against engine overheating. OAT coolant
(conforming to MS.90032) is recommended.
Winter Operation
To ensure the best possible heater and
defroster performance, make sure the engine
cooling system is functioning properly and the
proper amount, type, and concentration of
coolant is used. Use of the Air Recirculation
mode during Winter months is not recom -
mended, because it may cause window fogging.
Vacation/Storage
Before you store your vehicle, or keep it out of
service (i.e., vacation) for two weeks or more,
run the air conditioning system at idle for about
five minutes, in fresh air with the blower setting
on high. This will ensure adequate system lubri -
cation to minimize the possibility of compressor
damage when the system is started again.
Window Fogging
Vehicle windows tend to fog on the inside in
mild, rainy, and/or humid weather. To clear the
windows, select Defrost or Mix mode and
increase the front blower speed. Do not use the
Recirculation mode without A/C for long
periods, as fogging may occur.
CAUTION!
Failure to follow these cautions can cause
damage to the heating elements:
Use care when washing the inside of the
rear window. Do not use abrasive window
cleaners on the interior surface of the
window. Use a soft cloth and a mild
washing solution, wiping parallel to the
heating elements. Labels can be peeled off
after soaking with warm water.
Do not use scrapers, sharp instruments, or
abrasive window cleaners on the interior
surface of the window.
Keep all objects a safe distance from the
window.
2

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70GETTING TO KNOW YOUR VEHICLE
Reprogramming A Single HomeLink® Button
(Non-Rolling Code)
To reprogram a channel that has been previ -
ously trained, follow these steps:

1. Place the ignition in the ON/RUN position.

2. Press and hold the desired HomeLink® button until the indicator light begins to
flash after 20 seconds. Do not release the
button.
3. Without releasing the button, proceed with “Programming A Non-Rolling Code” step 2
and follow all remaining steps.
Canadian/Gate Operator Programming
For programming transmitters in Canada/
United States that require the transmitter
signals to “time-out” after several seconds of
transmission.
Canadian radio frequency laws require trans -
mitter signals to time-out (or quit) after several
seconds of transmission – which may not be
long enough for HomeLink® to pick up the
signal during programming. Similar to this
Canadian law, some U.S. gate operators are
designed to time-out in the same manner. It may be helpful to unplug the device during the
cycling process to prevent possible overheating
of the garage door or gate motor.

1. Place the ignition in the ON/RUN position.

2. Place the hand-held transmitter 1 to
3 inches (3 to 8 cm) away from the Home-
Link® button you wish to program while
keeping the HomeLink® indicator light in
view.
3. Continue to press and hold the HomeLink® button, while you press and release
(“cycle”) your hand-held transmitter every
two seconds until HomeLink® has success-
fully accepted the frequency signal. The
indicator light will flash slowly and then
rapidly when fully trained.
4. Watch for the HomeLink® indicator to change flash rates. When it changes, it is
programmed. It may take up to 30 seconds
or longer in rare cases. The garage door
may open and close while you are program -
ming. 5. Press and hold the programmed Home
-
Link® button and observe the indicator
light.
NOTE:
If the indicator light stays on constantly,
programming is complete and the garage
door/device should activate when the
HomeLink® button is pressed.
To program the two remaining HomeLink®
buttons, repeat each step for each
remaining button. DO NOT erase the chan -
nels.
If you unplugged the garage door opener/
device for programming, plug it back in at this
time.
Reprogramming A Single HomeLink® Button
(Canadian/Gate Operator)
To reprogram a channel that has been previ -
ously trained, follow these steps:

1. Place the ignition in the ON/RUN position.
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183
(Continued)
STARTING AND OPERATING
STARTING THE ENGINE — GAS ENGINE
Before starting your vehicle, adjust your seat,
adjust both inside and outside mirrors, and
fasten your seat belt.
The starter should not be operated for more
than 10-second intervals. Waiting a few
seconds between such intervals will protect the
starter from overheating.
Automatic Transmission
Start the engine with the transmission in PARK
position. Apply the brake before shifting into any
driving range.NOTE:
This vehicle is equipped with a transmission
shift interlocking system. The brake pedal
must be pressed to shift out of PARK.
If equipped with an 8-speed transmission,
starting the vehicle in NEUTRAL is not
possible unless the Manual Park Release has
been activated. For the Manual Park Release
operation refer to Manual Park Release in “In
Case Of Emergency”.
Tip Start Feature
Do not
press the accelerator. Cycle the ignition
switch briefly to the START position and release
it. The starter motor will continue to run and will
automatically disengage when the engine is
running.
WARNING!
When leaving the vehicle, always make
sure the keyless 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.
Do not leave children or animals inside
parked vehicles in hot weather. Interior
heat build-up may cause serious injury or
death.
WARNING! (Continued)
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STARTING AND OPERATING187
(Continued)
If the engine has been flooded, it may start to
run, but not have enough power to continue
running when the ignition button/key is
released. If this occurs, continue cranking with
the accelerator pedal pushed all the way to the
floor. Release the accelerator pedal and the
ignition button/key once the engine is running
smoothly.
If the engine shows no sign of starting after a 10
second period of engine cranking with the
accelerator pedal held to the floor, wait 10 to 15
seconds, then repeat the “Normal Starting”
procedure.
Cold Weather Operation (Below –22°F Or
−30°C)
To ensure reliable starting at these tempera -
tures, use of an externally powered electric
engine block heater (available from your autho -
rized dealer) is recommended.
After Starting
The idle speed is controlled automatically, and
it will decrease as the engine warms up.
STARTING THE ENGINE — DIESEL ENGINE
Before starting your vehicle, adjust your seat,
adjust both inside and outside mirrors, and
fasten your seat belts.
The starter should not be operated for more
than 25-second intervals. Waiting a few
minutes between such intervals will protect the
starter from overheating.
Automatic Transmission
Start the engine with the transmission in the
NEUTRAL or PARK position. Apply the brake
before shifting to any driving range.
CAUTION!
To prevent damage to the starter, do not
crank the engine for more than 10 seconds at
a time. Wait 10 to 15 seconds before trying
again.
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 remove
the key fob 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 children), 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)
5

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200STARTING AND OPERATING
Operating Precautions
Avoid Overheating The Engine
The temperature of the engine coolant (anti -
freeze: a mixture of 50% ethylene-glycol and
50% water) must not exceed the normal range
of the temperature gauge 240°F (116°C) with
a 21 psi (145 kPa) coolant pressure cap.
Usually the engine coolant (antifreeze)
temperature indicated during operation will be
to the left of center in the normal range of the
gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low engine coolant (anti -
freeze) temperature below the normal range on
the gauge 140°F (60°C) can be harmful to the
engine. Low engine coolant (antifreeze)
temperature can cause incomplete combustion
which allows carbon and varnish to form on
piston rings and injector nozzles. Also, the
unburned fuel can enter the crankcase, diluting
the lubricating oil and causing rapid wear to the
engine.
Cooling System Tips
To reduce potential for engine and transmission
overheating in high ambient temperature condi -
tions, take the following actions:
City Driving — When stopped, shift the trans -
mission into NEUTRAL and increase engine
idle speed.
Highway Driving — Reduce your speed.
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.
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.

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210STARTING AND OPERATING
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 trucks with AS66RC or AS69RC transmis -
sion, FIFTH and SIXTH gears may be inhibited
briefly on cold starts below 41°F (5°C), and
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 third gear (for AS66RC/AS69RC transmis -
sion) regardless of which forward gear is
selected. If an AS66RC/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 to the OFF position.
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.

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212STARTING AND OPERATING
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.
Vehicle speed is sufficiently high.
The TOW/HAUL switch has not been
activated.
The driver is not heavily pressing the
accelerator.
Torque Converter Clutch
A feature designed to improve fuel economy
has been included in the automatic transmis -
sion on your vehicle. A clutch within the torque
converter engages automatically at calibrated
speeds. This may result in a slightly different feeling or response during normal operation in
the upper gears. When the vehicle speed drops
or during some accelerations, the clutch auto
-
matically disengages.
NOTE:
The torque converter clutch will not engage,
until the transmission fluid and engine
coolant are warm (usually after 1 to 3 miles
(2 to 5 km) of driving). Because engine speed
is higher when the torque converter clutch is
not engaged, it may seem as if the transmis -
sion is not shifting properly when cold. This is
normal. Using the Electronic Range Select
(ERS) shift control, when the transmission is
sufficiently warm, will demonstrate that the
transmission is able to shift into and out of
Overdrive.
If the vehicle has not been driven for several
days, the first few seconds of operation after
shifting the transmission into gear may seem
sluggish. This is due to the fluid partially
draining from the torque converter into the
transmission. This condition is normal and
will not cause damage to the transmission.
The torque converter will refill within five
seconds after starting the engine.
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

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218STARTING AND OPERATING
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.
AUXILIARY SWITCHES — IF EQUIPPED
There can be up to six auxiliary switches located
in the lower switch bank of the instrument panel
which can be used to power various electronic
devices and PTO (Power Take Off) – If Equipped.
If Power Take Off is equipped, it will take the
place of the sixth Auxiliary switch. Connections
to the switches are found under the hood in the
connectors attached to the auxiliary Power
Distribution Center. You have the ability to configure the function
-
ality of the auxiliary switches via the instrument
cluster display. All switches can now be config -
ured for setting the switch type operation to
latching or momentary, power source of either
battery or ignition, and ability to hold last state
across key cycles.
NOTE:
Holding last state conditions are met when
switch type is set to latching and power source
is set to ignition.
For further information on using the auxiliary
switches, please refer to the Ram Body Builders
Guide by accessing www.rambodybuilder.com
and choosing the appropriate links.
FOUR-WHEEL DRIVE OPERATION — IF
EQUIPPED
Four-wheel drive trucks are equipped with
either a manually shifted transfer case or an
electronically shifted transfer case. Refer to the
operating instructions for your transfer case,
located in this section for further information.
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.

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