towing RAM CHASSIS CAB 2019 User Guide

SAFETY 165
Towing With HSA
HSA will also provide assistance to mitigate roll back while
towing a trailer. Disabling And Enabling HSA
This feature can be turned on or turned off. To change the
current setting, proceed as follows:
• If disabling HSA using your instrument cluster display,
refer to “Instrument Cluster Display” in “Getting To Know
Your Instrument Panel” for further information.
• If disabling HSA using Uconnect Settings, refer to “Ucon -
nect Settings” in “Multimedia” for further information.
For vehicles not equipped with an instrument cluster
display, perform the following steps:
1. Center the steering wheel (front wheels pointing straight
forward).
2. Shift the transmission into PARK.
3. Apply the parking brake.
4. Start the engine.
5. Rotate the steering wheel slightly more than one-half turn
to the left.WARNING!
• If you use a trailer brake controller with your trailer, the
trailer brakes may be activated and deactivated with
the brake switch. If so, there may not be enough brake
pressure to hold both the vehicle and the trailer on a
hill when the brake pedal is released. In order to avoid
rolling down an incline while resuming acceleration,
manually activate the trailer brake or apply more
vehicle brake pressure prior to releasing the brake
pedal.
• HSA is not a parking brake. Always apply the parking
brake fully when exiting your vehicle. Also, be certain
to place the transmission in PARK.
• Failure to follow these warnings can result in a colli -
sion or serious personal injury. 4

170 SAFETY
The “ESC OFF Indicator Light” indicates the
customer has elected to have the Electronic Stability
Control (ESC) in a reduced mode.
Electronic Roll Mitigation (ERM)
This system anticipates the potential for wheel lift by moni -
toring the driver’s steering wheel input and the speed of the
vehicle. When ERM determines that the rate of change of the
steering wheel angle and vehicle’s speed are sufficient to
potentially cause wheel lift, it then applies the appropriate
brake and may also reduce engine power to lessen the chance
that wheel lift will occur. ERM can only reduce the chance of
wheel lift occurring during severe or evasive driving maneu -
vers; it cannot prevent wheel lift due to other factors, such as
road conditions, leaving the roadway, or striking objects or
other vehicles.
NOTE:
ERM is disabled anytime the ESC is in “Full Off” mode (if
equipped). Refer to “Electronic Stability Control (ESC)” in
this section for a complete explanation of the available ESC
modes. Trailer Sway Control (TSC)
TSC uses sensors in the vehicle to recognize an excessively
swaying trailer and will take the appropriate actions to
attempt to stop the sway. TSC will become active automati -
cally once an excessively swaying trailer is recognized.
NOTE:
TSC cannot stop all trailers from swaying. Always use
caution when towing a trailer and follow the trailer tongue
weight recommendations. Refer to “Trailer Towing” in
“Starting And Operating” for further information. WARNING!
Many factors, such as vehicle loading, road conditions
and driving conditions, influence the chance that wheel
lift or rollover may occur. ERM cannot prevent all wheel
lift or roll overs, especially those that involve leaving the
roadway or striking objects or other vehicles. The
capabilities of an ERM-equipped vehicle must never be
exploited in a reckless or dangerous manner which could
jeopardize the user's safety or the safety of others.

260 STARTING AND OPERATING
NEUTRAL (N)
Use this range when the vehicle is standing for prolonged
periods with the engine running. The engine may be started
in this range. Apply the parking brake and shift the transmis -
sion into PARK if you must exit the vehicle.
DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and downshifts, and the best fuel economy. The transmission automatically
upshifts through underdrive first, second, and third gears,
direct fourth gear and overdrive fifth and sixth gears. The
DRIVE position provides optimum driving characteristics
under all normal operating conditions.
When frequent transmission shifting occurs (such as when
operating the vehicle under heavy loading conditions, in
hilly terrain, traveling into strong head winds, or while
towing a heavy trailer), use the Electronic Range Select (ERS)
shift control (refer to “Electronic Range Select (ERS) Opera -
tion” in this section for further information) to select a lower
gear range. Under these conditions, using a lower gear range
will improve performance and extend transmission life by
reducing excessive shifting and heat buildup.
If the transmission temperature exceeds normal operating
limits, the powertrain controller will modify the transmis -
sion shift schedule and expand the range of torque converter
clutch engagement. This is done to prevent transmission
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.WARNING!
Do not coast in NEUTRAL and never turn off the
ignition to coast down a hill. These are unsafe practices
that limit your response to changing traffic or road
conditions. You might lose control of the vehicle and
have a collision.
CAUTION!
Towing the vehicle, coasting, or driving for any other
reason with the transmission in NEUTRAL can cause
severe transmission damage. Refer to “Recreational
Towing” in “Starting And Operating” and “Towing A
Disabled Vehicle” in “In Case Of Emergency” for further
information.

STARTING AND OPERATING 261
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 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), oper -
ation 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 electronically for
abnormal 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
third gear 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 illuminated.
Limp Home Mode allows the vehicle to be driven to an
authorized dealer for service without damaging the trans -
mission.
In the event of a momentary problem, the transmission 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

264 STARTING AND OPERATING
• 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 trans -
mission. 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 transmission shifting occurs,
push the TOW/HAUL switch to activate TOW/HAUL
mode. This will improve performance and reduce the poten -
tial for transmission overheating or failure due to excessive
shifting. When operating in TOW/HAUL mode, transmis -
sion upshifts are delayed, and the transmission will automat -
ically downshift (for engine braking) when the throttle is
closed and/or during steady braking maneuvers. 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 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.

268 STARTING AND OPERATING
The following indicators should be used to ensure that you
have properly engaged the transmission into the PARK posi -
tion:
• Look at the transmission gear position display and verify
that it indicates the PARK position (P), and is not blinking.
• With brake pedal released, verify that the gear selector will
not move out of PARK.
REVERSE (R)
This range is for moving the vehicle backward. Shift into
REVERSE only after the vehicle has come to a complete stop. NEUTRAL (N)
Use this range when the vehicle is standing for prolonged
periods with the engine running. Apply the parking brake
and shift the transmission into PARK if you must exit the
vehicle.CAUTION!
• DO NOT race the engine when shifting from PARK or
NEUTRAL into another gear range, as this can damage
the drivetrain.
• Before moving the transmission gear selector out of
PARK, you must start the engine, and also press the
brake pedal. Otherwise, damage to the gear selector
could result. WARNING!
Do not coast in NEUTRAL and never turn off the
ignition to coast down a hill. These are unsafe practices
that limit your response to changing traffic or road
conditions. You might lose control of the vehicle and
have a collision.
CAUTION!
Towing the vehicle, coasting, or driving for any other
reason with the transmission in NEUTRAL can cause
severe transmission damage. Refer to “Recreational
Towing” in “Starting And Operating” and “Towing A
Disabled Vehicle” in “In Case Of Emergency” for further
information.

STARTING AND OPERATING 269
DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and downshifts,
and the best fuel economy. The transmission automatically
upshifts through all forward gears. The DRIVE position
provides optimum driving characteristics under all normal
operating conditions.
When frequent transmission shifting occurs (such as when
operating the vehicle under heavy loading conditions, in
hilly terrain, traveling into strong head winds, or while
towing a heavy trailer), select TOW/HAUL mode or use the
Electronic Range Select (ERS) shift control (refer to "Elec -
tronic Range Select (ERS) Operation" in this section for
further information) to select a lower gear range. Under
these conditions, using a lower gear range will improve
performance and extend transmission life by reducing exces -
sive shifting and heat buildup.
During extremely cold temperatures (-22°F [-30°C] or
below), transmission operation may be modified depending
on engine and transmission temperature as well as vehicle
speed. Normal operation will resume once the transmission
temperature has risen to a suitable level. Transmission Limp Home Mode
Transmission function is monitored electronically for
abnormal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. 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 illuminated. 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 transmission 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 (prefer -
ably, at an authorized dealer).
1. Stop the vehicle.
2. Shift the transmission into PARK, if possible. If not, shift
the transmission to NEUTRAL. 5

STARTING AND OPERATING 271
To exit ERS mode, simply push and hold the GEAR+ switch
until the gear limit display disappears from the instrument
cluster.
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 poten -
tial 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 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 downshift for additional engine braking on a
slippery surface. The drive wheels could lose their grip
and the vehicle could skid, causing a collision or
personal injury.
5

STARTING AND OPERATING 273
(Continued)This electronically shifted transfer case provides four mode
positions:
• Two-Wheel Drive High Range (2WD)
• Four-Wheel Drive High Range (4WD HIGH)
• Four-Wheel Drive Low Range (4WD LOW)
• Neutral (NEUTRAL)
For additional information on the appropriate use of each
transfer case mode position, see the information below:
2WD
Rear-Wheel Drive High Range — This range is for normal
street and highway driving on dry hard surfaced roads.
4WD HIGH
Four-Wheel Drive High Range — This range provides torque
to the front driveshaft (engages four-wheel drive) which
allows front and rear wheels to spin at the same speed. This
provides additional traction for loose, slippery road surfaces
only.
4WD LOW
Four-Wheel Drive Low Range — This range provides low
speed four-wheel drive. It maximizes torque (increased torque over 4WD HIGH) to the front driveshaft; allowing
front and rear wheels to rotate at the same speed. This range
provides additional traction and maximum pulling power
for loose, slippery road surfaces only. Do not exceed 25 mph
(40 km/h) in this range.
NEUTRAL (N)
Neutral — This range disengages both the front and rear
driveshafts from the powertrain. To be used for flat towing
behind another vehicle. Refer to “Recreational Towing” in
this section for further information.
WARNING!
• You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the
NEUTRAL (N) position without first fully engaging
the parking brake. The transfer case NEUTRAL (N)
position disengages both the front and rear drive shaft
from the powertrain, and will allow the vehicle to roll,
even if the transmission is in PARK. The parking brake
should always be applied when the driver is not in the
vehicle. 5

274 STARTING AND OPERATING
This electronically shifted transfer case is designed to be
driven in the two–wheel drive position (2WD) for normal
street and highway conditions on dry hard surfaced roads).
Driving the vehicle in 2WD will have greater fuel economy
benefits as the front axle is not engaged in 2WD.
When additional traction is required, the transfer case 4WD
HIGH and 4WD LOW positions can be used to maximize
torque to the front driveshaft, forcing the front and rear
wheels to rotate at the same speed. This is accomplished by
pushing the desired position on the 4WD control switch.
Refer to “Shifting Procedure” in this section for specific
shifting instructions.
The 4WD HIGH and 4WD LOW positions are designed for
loose, slippery road surfaces only. Driving in the 4WD HIGH and 4WD LOW positions on dry hard surfaced roads may
cause increased tire wear and damage to the driveline
components.
NOTE:
The transfer case NEUTRAL button is located in the center of
the 4WD Control Switch and is pushed by using a ballpoint
pen or similar object. The transfer case NEUTRAL position is
to be used for recreational towing only. Refer to “Recre -
ational Towing” in “Starting And Operating” for further
information.
Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights (4WD and
4LOW) are located in the instrument cluster and indicate the
current and desired transfer case selection. When you select
a different transfer case position, the indicator lights will do
the following:
If All Of The Following Shift Conditions Are Met:
1. The current position indicator light will turn OFF.
2. The selected position indicator light will flash until the
transfer case completes the shift.• The transmission may not engage PARK if the vehicle
is moving. Always bring the vehicle to a complete stop
before shifting to PARK, and verify that the transmis -
sion gear position indicator solidly indicates PARK (P)
without blinking. Ensure that the vehicle is completely
stopped, and the PARK position is properly indicated,
before exiting the vehicle. WARNING! (Continued)