RAM CHASSIS CAB 2019 Owners Manual
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STARTING AND OPERATING 279
Because four-wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds. Do
not go faster than road conditions permit.
NOTE:
Delayed  shifts  out  of  four-wheel  drive  may  be  experienced
due to uneven tire wear, low or uneven tire pressures, exces -
sive vehicle loading, or cold temperatures.
Two-Wheel Drive High Range (2H)
Rear-Wheel  Drive  High  Range  —  This  range  is  for  normal
street and highway driving on dry hard surfaced roads. Four-Wheel Drive High Range (4H)
Four-Wheel Drive High Range — This range locks the front
and  rear  driveshafts  together  forcing  the  front  and  rear
wheels  to  rotate  at  the  same  speed.  Additional  traction  for
loose, slippery road surfaces only.
Neutral (N)
Neutral — This range disengages the front and rear drivesh -
afts  from  the  powertrain.  To  be  used  for  flat  towing behind
another vehicle. Refer to “Recreational Towing” in “Starting
And Operating” for further information.
Four-Wheel Drive Low Range (4L)
Four-Wheel  Drive  Low  Range  —  This  range  locks  the  front
and  rear  driveshafts  together  forcing  the  front  and  rear
wheels  to  rotate  at  the  same  speed.  Additional  traction  and
maximum  pulling  power  for  loose,  slippery  road  surfaces
only. Do not exceed 25 mph (40 km/h).WARNING!
 You or others could be injured or killed if you leave the
vehicle  unattended  with  the  transfer  case  in  the
NEUTRAL  position  without  first  fully  engaging  the
parking  brake.  The  transfer  case  NEUTRAL  position
disengages  both  the  front  and  rear  drive  shafts  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. 
CAUTION!
Do not use 4L (Low) range when operating the vehicle on
dry pavement. Driveline hardware damage can result. 5 
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280 STARTING AND OPERATING
Shifting Procedure — Manually Shifted Transfer Case
2H To 4H
Shifting  between  2H  and  4H  can  be  made  with  the  vehicle
stopped or in motion. If the vehicle is in motion, shifts can be
made  up  to  55 mph  (88 km/h).  With  the  vehicle  in  motion,
the  transfer  case  will  engage/disengage  faster  if  you
momentarily  release  the  accelerator  pedal  after  completing
the  shift.  Apply  a  constant  force  when  shifting  the  transfer
case lever.
2H Or 4H To 4L
NOTE:
When  shifting  into  or  out  of  4L  some  gear  noise  may  be
heard.  This  noise  is  normal  and  is  not  detrimental  to  the
vehicle or occupants.
With the vehicle rolling at 2 to 3 mph (3 to 5 km/h), shift the
transmission into NEUTRAL. While the vehicle is coasting at
2 to 3 mph (3 to 5 km/h), shift the transfer case  lever firmly
to  the  desired  position.  Do  not  pause  in  transfer  case
NEUTRAL. NOTE:
• Pausing  in  transfer  case  NEUTRAL  in  vehicles  equipped
with  an  automatic  transmission  may  require  shutting  the
engine OFF to avoid gear clash while completing the shift.
If difficulty occurs, shift the transmission into NEUTRAL,
hold  your  foot  on  the  brake,  and  turn  the  engine  OFF.
Complete the range shift to the desired mode.
• Shifting  into  or  out  of  4L  is  possible  with  the  vehicle
completely stopped, however  difficulty may occur due to
the mating clutch teeth not being properly aligned. Several
attempts  may  be  required  for  clutch  teeth  alignment  and
shift completion to occur. The preferred method is with the
vehicle rolling 2 to 3 mph (3 to 5 km/h). Avoid attempting
to engage or disengage  4L with the  vehicle  moving  faster
than 2 to 3 mph (3 to 5 km/h).
• Do not attempt to shift into or out of 4L while the transmis -
sion is in gear.
Transfer Case Position Indicator Light
The  “Transfer  Case  Position  Indicator  Light”  in  the  instru -
ment  cluster  is  used  to  alert  the  driver  that  the  front  axle  is
fully engaged and all four wheels are driving. 
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LIMITED-SLIP DIFFERENTIAL 
The  limited-slip  differential  provides  additional  traction  on
snow, ice,  mud, sand and  gravel, particularly when  there  is
a  difference  between  the  traction  characteristics  of  the
surface  under the right  and left rear  wheels. During normal
driving  and  cornering,  the  limited-slip  unit  performs  simi -
larly  to  a  conventional  differential.  On  slippery  surfaces,
however,  the  differential delivers  more of the  driving effort
to the rear wheel having the better traction.
The limited-slip differential is especially helpful during slip -
pery driving conditions. With both rear wheels on a slippery
surface,  a  slight  application  of  the  accelerator  will  supply
maximum traction. When  starting with  only one rear wheel
on  an  excessively  slippery  surface,  slight  momentary  appli -
cation  of  the  parking  brake  may  be  necessary  to  gain
maximum traction. Care  should  be  taken  to  avoid  sudden  accelerations  when
both rear wheels are on a slippery surface. This could cause
both rear wheels to spin, and allow the vehicle to slide side -
ways on the crowned surface of a road or in a turn.
POWER TAKE OFF OPERATION — IF EQUIPPED 
(CHASSIS CAB ONLY) 
This vehicle when equipped with PTO Prep and the AS66RC
automatic six-speed, will allow for an aftermarket upfit with
a  transmission  driven  PTO  (power  take  off).  The  customer
will  have  the  ability  to  operate  the  PTO  in  either  a
“stationary” or “mobile” mode. The vehicles will be factory
set  to  the  “stationary”  mode.  To  select  “mobile”  mode,  you
will need to enter the commercial vehicle menu on the instru -
ment  cluster  screen  and select mobile  PTO  mode.  Details of
the  PTO  selection  modes  and  further  PTO  information  is
available  at  the  Ram  Truck  Bodybuilders  web  site:
www.rambodybuilder.com .
AS66RC Six-Speed Automatic Transmission Only
The PTO drive gear (part of the AS66RC) operates at torque
converter turbine speed. The turbine speed will be less than
engine  speed  when  the  torque  converter  clutch  is  not
engaged  and will be same as  engine speed when the torque
converter clutch is engaged.WARNING!
On  vehicles  equipped  with  a  limited-slip  differential
never run the engine with one rear wheel off the ground
since  the  vehicle  may  drive  through  the  rear  wheel
remaining  on  the  ground.  You  could  lose  control  of  the
vehicle. 5 
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282 STARTING AND OPERATING
Stationary Mode
To  operate  the  PTO  in  this  mode  the  vehicle  must  meet  the
following conditions:
• Transmission in PARK position.
• PTO switch has been activated.
• Brake pedal must not be applied.
• Vehicle engine must be running.
• No vehicle, or brake faults present.
• PTO must be correctly installed using the vehicle provided
circuits.
The instrument cluster will display a "PTO On" message for
five seconds if  the  above conditions are met. Otherwise, the
instrument  cluster  will  display  a  message  "To  Operate  PTO
Shift  To  Park"  indicating  what  operator  action  should  be
taken to engage the PTO mode.
The customer has the choice to operate the PTO by utilizing
the  cruise  control  switches  or  by  utilizing  a  remote  control
(provided by the PTO supplier). To operate the feature using
the  cruise  control  switches,  the  customer  must  first  activate
the  PTO  switch  which  will  turn  on  the  PTO.  In  order  to
increase  or  decrease  the  engine  idle  speed,  to  optimize  the
PTO function, the “RESUME/ACCEL” and “DECEL” cruise switches can be used respectively. To disengage PTO opera -
tion  and  return  to  “standard  vehicle  operation”  simply
toggle the PTO switch to the OFF position.
The torque converter clutch (TCC) will automatically engage
at  engine  speeds  above  1,200  RPM  (engine  speed)  in  PTO
stationary  mode.  Once  engaged,  the  TCC  will  remain
applied  and  will  not  disengage  until  the  engine  speed  falls
below  1,000  RPM.  TCC  engagement  is  desirable  for  certain
types of PTO applications (Automatic Transmission Only).
To operate  the  PTO via a remote switch, the customer must
make sure the above conditions are met. It is vital for proper
operation  that  the  PTO  and  remote  have  been  installed
correctly,  paying  special  attention  to  ensure  the  vehicle
provided  wiring  has  been  connected  properly.  This  is  the
responsibility  of  the  installer  of  the  PTO  and  switches/
remote  system.  It  is  the  responsibility  of  the  PTO  manufac -
turer  to  ensure  that  their  electrical  (switches  and  remote)
system is compatible with the vehicle’s electrical architecture
and software functionality.
NOTE:
Single  set  speed  can  be  programmed  via  the  PTO  menu  on
the  instrument  cluster  display.  Further  details  are  available
at the Ram Truck Bodybuilders web site located at  rambody -
builder.com 
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STARTING AND OPERATING 283
Mobile Mode
To  operate  the  PTO  in  this  mode  the  vehicle  must  meet  the
following conditions:
• Mobile mode is activated via the menu on  the  instrument
cluster display.
• (ON/OFF) switch has been activated.
• Transmission must be in PARK or DRIVE.
• Parking brake must not be applied.
• Brake pedal must not be applied.
• No vehicle or brake faults present.
• Vehicle engine must be running.
• PTO must be correctly installed using the vehicle provided
circuits.
The customer may choose to use the PTO while the vehicle is
moving. To do so, the PTO function must be activated prior
to  taking  the  vehicle  out  of  PARK.  This  is  accomplished  by
activating  the  upfitter-provided  PTO  on/off  switch.  At  this
point,  the  customer  may  place  the  vehicle  in  a  forward  or
reverse gear and have PTO operation once the vehicle begins
to  move.  To  disengage  PTO  operation  and  return  to  “stan -
dard  vehicle  operation”  simply  toggle  the  on/off  switch  to
the OFF position. NOTE:
For application specific information with respect to PTO and
pump  requirements  and  additional  vehicle  information
(wiring  schematics,  preset  idle  values,  engine  speed  limits,
and  vehicle  hardware  and  software  requirements)  please
refer  to  the  Body  Builders  Guide  by  accessing  rambody -
builder.com  and choosing the appropriate links.
POWER STEERING
Hydraulic Power Steering
The  standard  power  steering  system  will  give  you  good
vehicle  response  and  increased  ease  of  maneuverability  in
tight  spaces.  The  system  will  provide  mechanical  steering
capability if power assist is lost.
If for some reason the power assist is interrupted, it will still
be possible to steer your vehicle. Under these conditions, you
will  observe  a  substantial  increase  in  steering  effort,  espe -
cially at very low vehicle speeds and during parking maneu -
vers. 5 
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284 STARTING AND OPERATING
NOTE:
• Increased  noise  levels  at  the  end  of  the  steering  wheel
travel are considered normal and do not indicate that there
is a problem with the power steering system.
• Upon  initial  start-up  in  cold  weather,  the  power  steering
pump may make noise for a short amount of time. This is
due  to  the  cold,  thick  fluid  in  the  steering  system.  This
noise should be considered normal, and it does not in any
way damage the steering system.
Power Steering Fluid Check
Checking the power steering fluid  level at a defined service
interval is not required. The  fluid should only be checked if
a  leak  is  suspected,  abnormal  noises  are  apparent,  and/or
the  system  is  not  functioning  as  anticipated.  Check  fluid level when the engine is cold and off. Coordinate inspection
efforts through an authorized dealer.
If  necessary,  add  fluid  to  restore  to  the  proper  indicated
level.  With  a  clean  cloth,  wipe  any  spilled  fluid  from  all
surfaces.  Refer  to  “Fluids  And  Lubricants”  in  “Technical
Specifications” for further information.CAUTION!
Prolonged  operation  of  the  steering system  at the end  of
the  steering  wheel  travel  will  increase  the  steering  fluid
temperature  and  it  should  be  avoided  when  possible.
Damage to the power steering pump may occur. WARNING!
Fluid level should be checked on a level surface and with
the  engine  off  to  prevent  injury  from  moving  parts  and
to  ensure  accurate  fluid  level  reading.  Do  not  overfill.
Use  only  manufacturer's  recommended  power  steering
fluid.
CAUTION!
Do  not  use  chemical  flushes  in  your  power  steering
system as the chemicals can damage your power steering
components.  Such  damage  is  not  covered  by  the  New
Vehicle Limited Warranty. 
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STARTING AND OPERATING 285
SPEED CONTROL 
When  engaged,  the  Speed  Control  takes  over  accelerator
operations at speeds greater than 20 mph (32 km/h).
The Speed Control buttons are located on the right side of the
steering wheel.
Speed Control Buttons NOTE:
In  order  to  ensure  proper  operation,  the  Speed  Control
System  has  been  designed  to  shut  down  if  multiple  speed
control  functions  are  operated  at  the  same  time.  If  this
occurs,  the  Speed  Control  System  can  be  reactivated  by
pushing the Speed Control On/Off button and resetting the
desired vehicle set speed.
To Activate
Push  the  On/Off  button  to  activate  the  Speed  Control.  The
cruise  indicator  light  in  the  instrument  cluster  display  will
illuminate. To turn the system off, push the On/Off button a
second  time.  The  cruise  indicator  light  will  turn  off.  The
system should be turned off when not in use.
1 — On/Off Button 3 — SET (-)
2 — RES (+) 4 — CANCEL WARNING!
Leaving the Speed Control system on when not  in use  is
dangerous.  You  could  accidentally  set  the  system  or
cause  it  to  go  faster  than  you  want.  You  could  lose
control  and  have  an  accident.  Always  leave  the  system
off when you are not using it.  5 
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286 STARTING AND OPERATING
To Set A Desired Speed
Turn the Speed Control on. When the vehicle has reached the
desired  speed,  push  the  SET  (-)  button  and  release.  Release
the  accelerator  and  the  vehicle  will  operate  at  the  selected
speed.
NOTE:
The  vehicle  should  be  traveling  at  a  steady  speed  and  on
level ground before pushing the SET (-) button.
To Vary The Speed Setting
To Increase Speed
When  the  Speed  Control  is  set,  you  can  increase  speed  by
pushing the RES (+) button.
The  driver’s  preferred  units  can  be  selected  through  the
instrument  panel  settings  if  equipped.  Refer  to  “Getting  To
Know  Your  Instrument  Panel”  for  more  information.  The
speed  decrement  shown  is  dependant  on  the  chosen  speed
unit of U.S. (mph) or Metric (km/h):
U.S. Speed (mph)  
• Pushing  the  RES  (+)  button  once  will  result  in  a  1 mph
increase  in  set  speed.  Each  subsequent  tap  of  the  button
results in an increase of 1 mph. • If  the  button  is  continually  pushed,  the  set  speed  will
continue  to  increase  until  the  button  is  released,  then  the
new set speed will be established.
Metric Speed (km/h)  
• Pushing  the  RES  (+)  button  once  will  result  in  a  1 km/h
increase  in  set  speed.  Each  subsequent  tap  of  the  button
results in an increase of 1 km/h.
• If  the  button  is  continually  pushed,  the  set  speed  will
continue  to  increase  until  the  button  is  released,  then  the
new set speed will be established.
To Decrease Speed
When  the  Speed  Control  is  set,  you  can  decrease  speed  by
pushing the SET (-) button.
The  driver’s  preferred  units  can  be  selected  through  the
instrument  panel  settings  if  equipped.  Refer  to  “Getting  To
Know  Your  Instrument  Panel”  for  more  information.  The
speed  decrement  shown  is  dependant  on  the  chosen  speed
unit of U.S. (mph) or Metric (km/h): 
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STARTING AND OPERATING 287
U.S. Speed (mph)  
• Pushing  the  SET  (-)  button  once  will  result  in  a  1 mph
decrease  in  set  speed.  Each  subsequent  tap  of  the  button
results in a decrease of 1 mph.
• If  the  button  is  continually  pushed,  the  set  speed  will
continue  to  decrease  until  the  button  is  released, then  the
new set speed will be established.
Metric Speed (km/h)  
• Pushing  the  SET  (-)  button  once  will  result  in  a  1 km/h
decrease  in  set  speed.  Each  subsequent  tap  of  the  button
results in a decrease of 1 km/h.
• If  the  button  is  continually  pushed,  the  set  speed  will
continue  to  decrease  until  the  button  is  released, then  the
new set speed will be established.
To Accelerate For Passing 
Press the accelerator as you would normally. When the pedal
is released, the vehicle will return to the set speed. Using Speed Control On Hills
The  transmission  may  downshift  on  hills  to  maintain  the
vehicle set speed.
NOTE:
The  Speed  Control  system  maintains  speed  up  and  down
hills. A slight speed change on moderate hills is normal.
On  steep  hills,  a  greater  speed  loss  or  gain  may  occur  so  it
may be preferable to drive without Speed Control.
WARNING!
Speed  Control  can  be  dangerous  where  the  system
cannot  maintain  a constant speed. Your  vehicle  could go
too  fast  for  the  conditions,  and  you  could  lose  control
and have an accident. Do not use Speed Control in heavy
traffic or on roads that are winding, icy, snow-covered or
slippery.  5 
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288 STARTING AND OPERATING
To Resume Speed
To  resume  a  previously  set  speed,  push  the  RES  (+)  button
and release. Resume can be used at any speed above 20 mph
(32 km/h).
To Deactivate
A soft tap on the brake pedal, pushing the CANCEL button,
or  normal  brake  pressure  while  slowing  the  vehicle  will
deactivate  the  Speed  Control  without  erasing  the  set  speed
from memory.
Pushing the On/Off button, or returning the ignition to OFF,
erases the set speed from memory.
ADAPTIVE CRUISE CONTROL (ACC) — IF EQUIPPED   
Adaptive Cruise Control (ACC) increases the driving conve -
nience  provided  by  cruise  control  while  traveling  on  high -
ways and major roadways. However, it is not a safety system
and not designed to prevent collisions.  Speed Control func -
tion performs differently. Please refer to the proper section
within this chapter.
ACC  will  allow  you  to  keep  cruise  control  engaged  in  light
to  moderate  traffic  conditions  without  the  constant  need  to
reset  your  cruise  control.  ACC  utilizes  a  radar  sensor  and  a forward  facing  camera  designed  to  detect  a  vehicle  directly
ahead of you.
NOTE:
• If the  sensor  does  not  detect a  vehicle  ahead  of you,  ACC
will maintain a fixed set speed.
• If the ACC sensor detects a vehicle ahead, ACC will apply
limited braking or accelerate (not to exceed the original set
speed)  automatically  to  maintain  a  preset  following
distance, while matching the speed of the vehicle ahead.
The Cruise Control system has two control modes:
• Adaptive Cruise Control mode for maintaining an appro -
priate distance between vehicles.
• Normal (Fixed Speed) Cruise Control mode for cruising at
a  constant  preset  speed.  For  additional  information,  refer
to  “Normal  (Fixed  Speed)  Cruise  Control  Mode”  in  this
section.
NOTE:
Normal  (Fixed  Speed)  Cruise  Control  will  not  react  to
preceding vehicles. Always be aware of the mode selected.
You  can  change  the  mode  by  using  the  Cruise  Control
buttons. The two control modes function differently. Always
confirm which mode is selected.