2020 Ram 3500 Chassis Cab cooling

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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STARTING AND OPERATING285
Automatic Transmission
The DRIVE range can be selected when towing.
The transmission controls include a drive
strategy to avoid frequent shifting when towing.
However, if frequent shifting does occur while in
DRIVE, select TOW/HAUL mode or select a lower
gear range (using the Electronic Range Select
(ERS) shift control).
NOTE:
Using TOW/HAUL mode or selecting a lower
gear range (using the ERS shift control) while
operating the vehicle under heavy loading
conditions will improve performance and
extend transmission life by reducing excessive
shifting and heat build up. This action will also
provide better engine braking.
Six-Speed Automatic Transmission Only
When towing a loaded trailer up steep grades at
low speeds (20 mph [32 km/h] or below),
holding your vehicle in first gear (using the ERS
shift control) can help to avoid transmission
overheating. If you regularly tow a trailer for more than
45 minutes of continuous operation, then
change the automatic transmission fluid and
filter(s) as specified for "police, taxi, fleet, or
frequent trailer towing." Refer to the “Mainte
-
nance Plan” for the proper maintenance inter -
vals.
NOTE:
Check the automatic transmission fluid level
before towing (Six-speed automatic only).
Tow/Haul Mode
To reduce potential for automatic transmission
overheating, activate TOW/HAUL mode when
driving in hilly areas, or select a lower gear
range (using the Electronic Range Select (ERS)
shift control) on more severe grades.
Speed Control — If Equipped
Do not use on hilly terrain or with heavy
loads.
When using the Speed Control, if you experi -
ence speed drops greater than 10 mph
(16 km/h), disengage until you can get back
to cruising speed.
Use Speed Control in flat terrain and with
light loads to maximize fuel efficiency.
Cooling System
To reduce potential for engine and transmission
overheating, take the following actions:
City Driving
In city traffic — while stopped, place the trans -
mission in NEUTRAL, but do not increase
engine idle speed.
Highway Driving
Reduce speed.
Temporarily turn off air conditioning.
5

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320IN CASE OF EMERGENCY
Preparations For Jump Start
The battery in your vehicle is located in the front
of the engine compartment, behind the left
headlight assembly.
NOTE:
The positive battery post may be covered with a
protective cap if equipped. Lift up on the cap to
gain access to the positive battery post. Do not
jump off fuses. Only jump directly off positive
post which has a positive (+) symbol on or
around the post.

Positive Battery Post
1. Apply the parking brake, shift the auto
-
matic transmission into PARK and turn the
ignition OFF.

2. Turn off the heater, radio, and all unneces -
sary electrical accessories.
3. If using another vehicle to jump start the battery, park the vehicle within the jumper
cables’ reach, apply the parking brake and
make sure the ignition is OFF.
Jump Starting Procedure
Connecting The Jumper Cables

1. Connect the positive
(+) end of the jumper
cable to the positive (+)
post of the
discharged vehicle.

NOTE:
Do not jump off fuses. Only jump directly off
positive post.
WARNING!
Take care to avoid the radiator cooling fan
whenever the hood is raised. It can start
anytime the ignition switch is ON. You can
be injured by moving fan blades.
Remove any metal jewelry such as rings,
watch bands and bracelets that could
make an inadvertent electrical contact. You
could be seriously injured.
Batteries contain sulfuric acid that can
burn your skin or eyes and generate
hydrogen gas which is flammable and
explosive. Keep open flames or sparks
away from the battery.
WARNING!
Do not allow vehicles to touch each other as
this could establish a ground connection and
personal injury could result.
WARNING!
Failure to follow this jump starting procedure
could result in personal injury or property
damage due to battery explosion.
CAUTION!
Failure to follow these procedures could
result in damage to the charging system of
the booster vehicle or the discharged vehicle.

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322IN CASE OF EMERGENCY
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.
GEAR SELECTOR OVERRIDE — 6–SPEED
TRANSMISSION
If a malfunction occurs and the gear selector
cannot be moved out of the PARK position, you
can use the following procedure to temporarily
move the gear selector:

1. Turn the engine OFF.

2. Firmly apply the parking brake.
3. Tilt the steering wheel to the full up position.
4. Press and maintain firm pressure on the
brake pedal. 5. Insert a screwdriver or similar tool into the
access port (ringed circle) on the bottom of
the steering column, and push and hold the
override release lever up.

Gear Selector Override Access Port Location Gear Selector Override Access Port
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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330SERVICING AND MAINTENANCE
Maintenance Plan
Required Maintenance
Refer to the maintenance plan on the following
pages for required maintenance. More frequent
maintenance may be needed in severe condi -
tions, such as dusty areas and very short trip
driving. In some extreme conditions, additional
maintenance not specified in the maintenance
schedule may be required.
NOTE:
Using white lithium grease, lubricate the door
hinge pivot joints twice a year to prevent prema-
ture wear.At Every Oil Change Interval As Indicated By Oil Change Indicator System:
Change oil and filter.
Rotate the tires. Rotate at the first sign of
irregular wear, even if it occurs before the
oil indicator system turns on.
Inspect engine cooling system protection
and hoses.
Inspect exhaust system.
Inspect engine air cleaner if using in dusty
or off-road conditions. Replace air cleaner
filter, if necessary.
Inspect battery and clean and tighten termi -
nals as required.
Inspect the CV/Universal joints.
Inspect automatic transmission fluid if
equipped with dipstick.
Inspect brake pads, shoes, rotors, drums,
hoses and park brake.
Inspect front end, and lubricate — If
equipped with serviceable fittings.
Inspect and replace the Evaporative
System Fresh Air Filter as necessary,
replacement may be more frequent if
vehicle is operated in extreme dusty condi -
tions.
At Every Oil Change Interval As Indicated
By Oil Change Indicator System:

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342SERVICING AND MAINTENANCE
(Continued)
WARNING!
You can be badly injured working on or
around a motor vehicle. Do only service
work for which you have the knowledge and
the right equipment. If you have any doubt
about your ability to perform a service job,
take your vehicle to a competent mechanic.Failure to properly inspect and maintain
your vehicle could result in a component
malfunction and effect vehicle handling
and performance. This could cause an acci -
dent.
WARNING! (Continued)CAUTION!
***The manufacturer highly recommends
that all cooling system service, maintenance,
and repairs be performed by an authorized
dealer.

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354SERVICING AND MAINTENANCE
NOTE:
Ensure the glove compartment door hinges and
glove compartment travel stops are fully
engaged.
9. Reattach the glove compartment tension
tether by inserting the tether clip in the
glove compartment and sliding the clip
away from the face of the glove compart -
ment door.
Accessory Drive Belt Inspection
When inspecting accessory drive belts, small
cracks that run across ribbed surface of belt
from rib to rib, are considered normal. These
are not a reason to replace belt. However,
cracks running along a rib (not across) are not
normal. Any belt with cracks running along a rib
must be replaced. Also have the belt replaced if
it has excessive wear, frayed cords or severe
glazing.

Accessory Belt (Serpentine Belt)

Conditions that would require replacement:
Rib chunking (one or more ribs has sepa -
rated from belt body)
Rib or belt wear
Longitudinal belt cracking (cracks between
two ribs)
Belt slips
“Groove jumping" (belt does not maintain
correct position on pulley)
Belt broken (note: identify and correct
problem before new belt is installed)
Noise (objectionable squeal, squeak, or
rumble is heard or felt while drive belt is in
operation)
Some conditions can be caused by a faulty
component such as a belt pulley. Belt pulleys
should be carefully inspected for damage and
proper alignment.
Belt replacement on some models requires the
use of special tools, we recommend having your
vehicle serviced at an authorized dealer.
Draining Fuel/Water Separator Filter
There are two fuel filter assemblies. One is
located on the driver's side of the engine. The
best access to this water drain valve is from
under the hood. The second one is on the under
body, located in front of the rear axle above the
drive shaft on pick-up models. The Chassis Cab
models second filter location is on the frame
behind the front axle. The best access to this
water drain valve is from under the vehicle.
WARNING!
Do not attempt to inspect an accessory
drive belt with vehicle running.
When working near the radiator cooling fan,
disconnect the fan motor lead. The fan is
temperature controlled and can start at any
time regardless of ignition mode. You could
be injured by the moving fan blades.
You can be badly injured working on or
around a motor vehicle. Only do service
work for which you have the knowledge and
the proper equipment. If you have any
doubt about your ability to perform a
service job, take your vehicle to a compe -
tent mechanic.

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