2018 Ram 3500 Chassis Cab engine overheat

If the transmission temperature exceeds normal operating
limits, the powertrain controller will modify the transmis-
sion shift schedule and expand the range of torque con-
verter clutch engagement. This is done to prevent trans-
mission damage due to overheating.
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 additional heat
load on the cooling system. Downshifting 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 operation may be
modified depending on engine and transmission tempera-
ture 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 transmission fluid is warm (refer to the
“Note” under “Torque Converter Clutch” in this section).
On models with 66RFE transmission, top overdrive gear is
also inhibited until the transmission fluid is warm, and
during extremely cold temperatures (-16°F [-27°C] or be-
low), operation may briefly be limited to first and direct
gears only. On trucks with AS66RC transmission, 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 re-
duced. 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 electronically for ab-
normal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in fourth gear (for 66RFE transmission) or third gear (for
AS66RC transmission) regardless of which forward gear is
selected. If an AS66RC 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
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STARTING AND OPERATING 251

When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission 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 downshift (for engine braking) when the
throttle is closed and/or during steady braking maneu-
vers.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 operation. 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 use the “TOW/HAUL” feature when driving in
icy or slippery conditions. The increased engine brak-
ing 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 result-
ing in personal injury or death.
Torque Converter Clutch
A feature designed to improve fuel economy has been
included in the automatic transmission 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 automatically disengages.
TOW/HAUL Switch
254 STARTING AND OPERATING

Towing Tips
Before setting out on a trip, practice turning, stopping, and
backing up the trailer in an area located away from heavy
traffic.
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 shift-
ing 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 per-
formance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
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 transmis-
sion fluid and filter(s) as specified for police, taxi, fleet, or
frequent trailer towing. Refer to the “Maintenance Plan”
for the proper maintenance intervals.
Seven-Pin Connector
1 — Battery 5 — Ground
2 — Backup Lamps 6 — Left Stop/Turn
3 — Right Stop/Turn 7 — Running Lamps
4 — Electric Brakes
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STARTING AND OPERATING 305

NOTE:Check the automatic transmission fluid level be-
fore towing.
Tow/Haul Mode
To reduce potential for automatic transmission overheat-
ing, 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 experience 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 overheat-
ing, take the following actions:
City Driving
In city traffic — while stopped, place the transmission in
NEUTRAL, but do not increase engine idle speed. Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
Air Suspension System
To aid in attaching/detaching the trailer from the vehicle,
the air suspension system can be used. Refer to “Air
Suspension System” in “Starting And Operating” for fur-
ther information.
NOTE:
The vehicle must remain in the engine running
position while attaching a trailer for proper leveling of the
air suspension system.
SNOWPLOW
2500/3500 Models Only
Snowplow Prep Packages are available as a factory in-
stalled option. These packages include components neces-
sary to equip your vehicle with a snowplow.
306 STARTING AND OPERATING

Vehicle front end wheel alignment was set to specifications
at the factory without consideration for the weight of the
plow. Front end toe-in should be checked and reset if
necessary at the beginning and end of the snowplow
season. This will help prevent uneven tire wear.
The blade should be lowered whenever the vehicle is
parked.
Maintain and operate your vehicle and snowplow equip-
ment following the recommendations provided by the
specific snowplow manufacturer.
Over The Road Operation With Snowplow Attached
The blade restricts air flow to the radiator and causes the
engine to operate at higher than normal temperatures.
Therefore, when transporting the plow, angle the blade
completely and position it as low as road or surface
conditions permit. Do not exceed 40 mph (64 km/h). The
operator should always maintain a safe stopping distance
and allow adequate passing clearance.
Operating Tips
Under ideal snow plowing conditions, 20 mph (32 km/h)
should be maximum operating speed. The operator shouldbe familiar with the area and surface to be cleaned. Reduce
speed and use extreme caution when plowing unfamiliar
areas or under poor visibility.
General Maintenance
Snowplows should be maintained in accordance with the
plow manufacturer’s instructions.
Keep all snowplow electrical connections and battery ter-
minals clean and free of corrosion.
When plowing snow, to avoid transmission and drivetrain
damage, the following precautions should be observed.
•
Operate with transfer case in 4LO when plowing small
or congested areas where speeds are not likely to exceed
15 mph (24 km/h). At higher speeds operate in 4HI.
• Vehicles with automatic transmissions should use 4LO
range when plowing deep or heavy snow for extended
periods of time to avoid transmission overheating.
• Do not shift the transmission unless the engine has
returned to idle and wheels have stopped. Make a
practice of stepping on the brake pedal while shifting the
transmission.
308 STARTING AND OPERATING

IN CASE OF EMERGENCY
CONTENTS
HAZARD WARNING FLASHERS ............318
 ASSIST AND SOS MIRROR — IF EQUIPPED . . . .318
 BULB REPLACEMENT ....................323
▫ Replacement Bulbs .....................323
▫ Replacing Exterior Bulbs ..................324
 FUSES ............................... .329
▫ Power Distribution Center ................330
 JACKING AND TIRE CHANGING ...........337
▫ 4500/5500 Models ..................... .337
▫ Preparations For Jacking ..................338
▫ Jacking Instructions 4500 And 5500 Series ......338
▫ To Stow The Flat Or Spare — If Equipped .....342
▫ Hub Caps/Wheel Covers — If Equipped ......342
JUMP STARTING ....................... .343
▫ Preparations For Jump Start ...............344
▫ Jump Starting Procedure ..................345
 IF YOUR ENGINE OVERHEATS .............346
 GEAR SELECTOR OVERRIDE ..............347
 FREEING A STUCK VEHICLE ..............348
 TOWING A DISABLED VEHICLE ............350
▫ Two-Wheel Drive Models .................351
▫ Four-Wheel Drive Models .................352
▫ Emergency Tow Hooks — If Equipped ........352
 ENHANCED ACCIDENT RESPONSE SYSTEM
(EARS) .............................. .353
 EVENT DATA RECORDER (EDR) ............353
7

CAUTION!
Do not connect jumper cable to any of the fuses on the
positive battery terminal. The resulting electrical cur-
rent will blow the fuse.
6. Once the engine is started, remove the jumper cables in the reverse sequence:
Disconnecting The Jumper Cables
1. Disconnect the negative (-)end of the jumper cable from
the engine ground of the vehicle with the discharged
battery.
2. Disconnect the opposite end of the negative (-)jumper
cable from the negative (-)post of the booster battery.
3. Disconnect the positive (+)end of the jumper cable from
the positive (+)post of the booster battery.
4. Disconnect the opposite end of the positive (+)jumper
cable from the positive (+)post of the vehicle with the
discharged battery.
If frequent jump starting is required to start your vehicle
you should have the battery and charging system in-
spected at an authorized dealer.
CAUTION!
Accessories plugged into the vehicle power outlets
draw power from the vehicle’s battery, even when not
in use (i.e., cellular devices, etc.). Eventually, if plugged
in long enough without engine operation, the vehicle’s
battery will discharge sufficiently to degrade battery
life and/or prevent the engine from starting.
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 transmission 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.
346 IN CASE OF EMERGENCY

WARNING!
Fast spinning tires can be dangerous. Forces generated
by excessive wheel speeds may cause damage, or even
failure, of the axle and tires. A tire could explode and
injure someone. Do not spin your vehicle’s wheels
faster than 30 mph (48 km/h) or for longer than 30
seconds continuously without stopping when you are
stuck and do not let anyone near a spinning wheel, no
matter what the speed.
CAUTION!
•Racing the engine or spinning the wheels may lead
to transmission overheating and failure. Allow the
engine to idle with the transmission in NEUTRAL
for at least one minute after every five rocking-
motion cycles. This will minimize overheating and
reduce the risk of clutch or transmission failure
during prolonged efforts to free a stuck vehicle.
• When “rocking” a stuck vehicle by shifting between
DRIVE/SECOND GEAR and REVERSE, do not spin
the wheels faster than 15 mph (24 km/h), or drive-
train damage may result.
• Revving the engine or spinning the wheels too fast
may lead to transmission overheating and failure. It
can also damage the tires. Do not spin the wheels
above 30 mph (48 km/h) while in gear (no transmis-
sion shifting occurring).
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IN CASE OF EMERGENCY 349