RAM 1500 2021 Owners Manual
Manufacturer: RAM, Model Year: 2021, Model line: 1500, Model: RAM 1500 2021Pages: 496, PDF Size: 20.89 MB
Page 141 of 496

GETTING TO KNOW YOUR INSTRUMENT PANEL139
If your OBD II system is not ready, you should 
see an authorized dealer or repair facility. If your 
vehicle was recently serviced or had a battery 
failure or replacement, you may need to do 
nothing more than drive your vehicle as you 
normally would in order for your OBD II system 
to update. A recheck with the above test routine 
may then indicate that the system is  now ready.
Regardless of whether your vehicle's OBD II 
system is ready or not, if the MIL is illuminated 
during normal vehicle operation you should 
have your vehicle serviced before going to the 
I/M station. The I/M station can fail your vehicle 
because the MIL is on with the engine running.
3
21_DT_OM_EN_USC_t.book  Page 139   
Page 142 of 496

140  (Continued)
(Continued)
STARTING AND OPERATING
STARTING THE ENGINE  
GASOLINE 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. DIESEL ENGINE
Before starting your vehicle, adjust your seat, 
both inside and outside mirrors, and fasten your 
seat belts.
The starter is allowed to crank for up to 
25-second intervals. Waiting a few minutes 
between such intervals will protect the starter 
from overheating.
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)WARNING!
Before exiting a vehicle, always come to a 
complete stop, then shift the automatic 
transmission into PARK and apply the 
parking brake.
Always make sure the ENGINE START/STOP 
button is in the OFF mode, key fob is 
removed from the vehicle and vehicle is 
locked.
Never leave children alone in a vehicle, or 
with access to an unlocked vehicle. Leaving 
children in a vehicle unattended 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.
21_DT_OM_EN_USC_t.book  Page 140   
Page 143 of 496

STARTING AND OPERATING141
(Continued)
NOTE:
Engine start up in very low ambient temperature 
could result in evident white smoke. This condi -
tion will disappear as the engine warms up.
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  Ú page 390.
AUTOPARK
AutoPark is a supplemental feature to assist in 
placing the vehicle in PARK should the 
situations on the following pages occur. It is a 
back up system and should not be relied upon  as the primary method by which the driver shifts 
the vehicle into PARK.
The conditions under which AutoPark will 
engage are outlined on the following pages.
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.
CAUTION!
The engine is allowed to crank as long as 
25 seconds. If the engine fails to start 
during this period, please wait at least two 
minutes for the starter to cool before 
repeating start procedure.
WARNING!
 (Continued)
If the “Water in Fuel Indicator Light” 
remains on, DO NOT START engine before 
you drain the water from the fuel filter to 
avoid engine damage  Ú page 412.
CAUTION! (Continued)
WARNING!
Driver inattention could lead to failure to 
place the vehicle in PARK. ALWAYS DO A 
VISUAL CHECK that your vehicle is in PARK 
by verifying that a solid (not blinking) “P” is 
indicated in the instrument cluster display 
and near the gear selector. If the “P” indi -
cator is blinking, your vehicle is not in 
PARK. As an added precaution, always 
apply the parking brake when exiting the 
vehicle.
AutoPark is a supplemental feature. It is not 
designed to replace the need to shift your 
vehicle into PARK. It is a back up system 
and should not be relied upon as the 
primary method by which the driver shifts 
the vehicle into PARK.
4
21_DT_OM_EN_USC_t.book  Page 141   
Page 144 of 496

142STARTING AND OPERATING  
If the vehicle is not in PARK and the driver turns 
off the engine, the vehicle may AutoPark.
AutoPark will engage when all of these 
conditions are met:
Vehicle is equipped with a rotary shifter and 
an 8-speed transmission
Vehicle is not in PARK
Vehicle speed is 1.2 mph (1.9 km/h) or less
Ignition switched from RUN to ACC
NOTE:
For Keyless Enter-N-Go equipped vehicles, the 
engine will turn off and the ignition switch will 
change to ACC mode. After 30 minutes the igni -
tion switches to OFF automatically, unless the 
driver turns the ignition switch OFF.
If the vehicle is not in PARK and the driver exits 
the vehicle with the engine running, the vehicle 
may AutoPark.
AutoPark will engage when all of these 
conditions are met:
Vehicle is equipped with a rotary shifter and 
an 8-speed transmission
Vehicle is not in PARK
Vehicle speed is 1.2 mph (1.9 km/h) or less
Driver’s seat belt is unbuckled
Driver’s door is ajar
Brake pedal is not pressed
The message “ AutoPark Engaged Shift to P then 
Shift to Gear ” will display in the instrument 
cluster.
NOTE:
In some cases the ParkSense graphic will be 
displayed in the instrument cluster, causing the 
“ AutoPark Engaged Shift to P then Shift to Gear ” 
message to not be seen. In these cases, the 
gear selector must be returned to “P” to select 
desired gear.
If the driver shifts into PARK while moving, the 
vehicle may AutoPark.
AutoPark will engage  ONLY when vehicle speed 
is 1.2 mph (1.9 km/h) or less.
The message “ Vehicle Speed is Too High to 
Shift to P ” will be displayed in the instrument 
cluster if vehicle speed is above 1.2 mph 
(1.9 km/h). 4WD LOW — If Equipped
AutoPark will be disabled when operating the 
vehicle in 4WD LOW.
The message “
AutoPark Disabled ” will be 
displayed in the instrument cluster.
Additional customer warnings will be given 
when all of these conditions are met:
Vehicle is not in PARK
Driver’s door is ajar
Vehicle is in 4WD LOW range
The message “ AutoPark Not Engaged ” will be 
displayed in the instrument cluster. A warning 
chime will continue until you shift the vehicle 
into PARK or the driver’s door is closed.
WARNING!
If vehicle speed is above 1.2 mph (1.9 km/h), 
the transmission will default to NEUTRAL until 
the vehicle speed drops below 1.2 mph 
(1.9 km/h). A vehicle left in the NEUTRAL 
position can roll. As an added precaution, 
always apply the parking brake when exiting 
the vehicle.
21_DT_OM_EN_USC_t.book  Page 142   
Page 145 of 496

STARTING AND OPERATING143
ALWAYS DO A VISUAL CHECK that your vehicle 
is in PARK by looking for the "P" in the 
instrument cluster display and near the gear 
selector. As an added precaution, always apply 
the parking brake when exiting the vehicle.
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.
KEYLESS ENTER-N-GO — IGNITION
This feature allows the driver to operate the 
ignition switch with the push of a button, as long 
as the Remote Start/Keyless Enter-N-Go key 
fob is in the passenger compartment.
NORMAL STARTING USING ENGINE 
START/S TOP B
UTTON — GASOLINE 
E
NGINE    
To Turn On The Engine Using The ENGINE 
START/STOP Button
1. The transmission must be in PARK.
2. Press and hold the brake pedal while pushing  the ENGINE START/STOP button once.
 3. The system starts the vehicle. If the vehicle 
fails to start, the starter will disengage 
automatically after 10 seconds.
4. If you wish to stop the cranking of the  engine prior to the engine starting, push the 
button again.
To Turn Off The Engine Using ENGINE START/
STOP Button
1. Place the gear selector in PARK, then push  and release the ENGINE START/STOP 
button. The ignition will return to the OFF 
mode.
2. If the gear selector is not in PARK, the  ENGINE START/STOP button must be held 
for two seconds or three short pushes in a 
row with the vehicle speed above 5 mph 
(8 km/h) before the engine will shut off. The 
ignition will remain in the ACC mode until 
the gear selector is in PARK and the button 
is pushed twice to the OFF mode.
3. If the gear selector is not in PARK and the  ENGINE START/STOP button is pushed 
once with the vehicle speed above 5 mph 
(8 km/h), the instrument cluster will display  a “
Vehicle Not In Park ” message and the 
engine will remain running. Never leave a 
vehicle out of the PARK position, or it could 
roll.
NOTE:
If the gear selector is not in PARK, and the 
ENGINE START/STOP button is pushed once 
with the vehicle speed below 5 mph (8 km/h), 
the engine will shut off and the ignition will 
remain in the ACC position. If vehicle speed 
drops below 1.2 mph (1.9 km/h), the vehicle 
may AutoPark  Ú page 141.
ENGINE START/STOP Button Functions — With 
Driver’s Foot OFF The Brake Pedal (In PARK Or 
NEUTRAL Position)
The ENGINE START/STOP button operates 
similar to an ignition switch. It has three modes: 
OFF, ACC, and RUN. To change the ignition 
modes without starting the vehicle and use the 
accessories, follow these directions:
1. Start with the ignition in the OFF mode.
2. Push the ENGINE START/STOP button once  to place the ignition to the ACC mode.
4
21_DT_OM_EN_USC_t.book  Page 143   
Page 146 of 496

144STARTING AND OPERATING  
(Continued)
3. Push the ENGINE START/STOP button a  second time to place the ignition to the RUN 
mode.
4. Push the ENGINE START/STOP button a  third time to return the ignition to the OFF 
mode.
If Engine Fails To Start 
If the engine fails to start after you have 
followed the “Normal Starting” procedure, it 
may be flooded. Push the accelerator pedal all 
the way to the floor and hold it there while the 
engine is cranking. This should clear any excess 
fuel in case the engine is flooded.
The starter motor will engage automatically, run 
for 10 seconds, and then disengage. Once this 
occurs, release the accelerator pedal and the 
brake pedal, wait 10 to 15 seconds, then repeat 
the “Normal Starting” procedure.
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.NORMAL STARTING USING ENGINE 
START/STOP B
UTTON — DIESEL 
E
NGINE    
Observe the instrument panel telltales when 
starting the engine.
NOTE:
Normal starting of either a cold or a warm 
engine is obtained without pumping or pressing 
the accelerator pedal.
To Turn On The Engine Using The ENGINE 
START/STOP Button
1. The transmission must be in PARK (P).
2. Press and hold the brake pedal while 
pushing the ENGINE START/STOP button 
once.
WARNING!
Never pour fuel or other flammable liquid 
into the throttle body air inlet opening in an 
attempt to start the vehicle. This could 
result in flash fire causing serious personal 
injury.
Do not attempt to push or tow your vehicle 
to get it started. Vehicles equipped with an 
automatic transmission cannot be started 
this way. Unburned fuel could enter the 
catalytic converter and once the engine has 
started, ignite and damage the converter 
and vehicle.
If the vehicle has a discharged battery, 
booster cables may be used to obtain a 
start from a booster battery or the battery in 
another vehicle. This type of start can be 
dangerous if done improperly   Úpage 386.
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!  (Continued)
21_DT_OM_EN_USC_t.book  Page 144   
Page 147 of 496

STARTING AND OPERATING145
NOTE:
A delay of the start, up to five seconds is 
possible under very cold conditions. The "Wait 
to Start" telltale will be illuminated during the 
pre-heat process. When the engine “Wait To 
Start” light goes off the engine will automati -
cally crank.
3. The system starts the vehicle. If the vehicle  fails to start, the starter will disengage 
automatically after 25 seconds.
4. If you wish to stop the cranking of the  engine prior to the engine starting, push the 
button again.
NOTE:
Normal starting of either a cold or a warm 
engine is obtained without pumping or pressing 
the accelerator pedal. To Turn Off The Engine Using ENGINE START/
STOP Button
1. Place the gear selector in PARK, then push 
and release the ENGINE START/STOP 
button. The ignition will return to the OFF 
mode.
2. If the gear selector is not in PARK, the  ENGINE START/STOP button must be held 
for two seconds or three short pushes in a 
row with the vehicle speed above 5 mph 
(8 km/h) before the engine will shut off. The 
ignition will remain in the ACC mode until 
the gear selector is in PARK and the button 
is pushed twice to the OFF mode.
3. If the gear selector is not in PARK and the  ENGINE START/STOP button is pushed 
once with the vehicle speed above 5 mph 
(8 km/h), the instrument cluster will display 
a “Vehicle Not In Park ” message and the 
engine will remain running. Never leave a 
vehicle out of the PARK position, or it could 
roll.
NOTE:
If the gear selector is not in PARK, and the 
ENGINE START/STOP button is pushed once 
with the vehicle speed below 5 mph (8 km/h),  the engine will shut off and the ignition will 
remain in the ACC position. If vehicle speed 
drops below 1.2 mph (1.9 km/h), the vehicle 
may AutoPark  Ú
page 141.
ENGINE START/STOP Button Functions — With 
Driver’s Foot OFF The Brake Pedal (In PARK Or 
NEUTRAL Position)
The ENGINE START/STOP button operates 
similar to an ignition switch. It has three modes: 
OFF, ACC, and RUN. To change the ignition 
modes without starting the vehicle and use the 
accessories, follow these directions:
1. Start with the ignition in the OFF mode.
2. Push the ENGINE START/STOP button once  to place the ignition to the ACC mode.
3. Push the ENGINE START/STOP button a  second time to place the ignition to the RUN 
mode.
4. Push the ENGINE START/STOP button a  third time to return the ignition to the OFF 
mode.
CAUTION!
If the “Water in Fuel Indicator Light” remains 
on, DO NOT START the engine before you 
drain the water from the fuel filter to avoid 
engine damage  Ú page 412.4
21_DT_OM_EN_USC_t.book  Page 145   
Page 148 of 496

146STARTING AND OPERATING  
(Continued)
COLD WEATHER OPERATION (BELOW 
–22°F O
R −30°C) 
To ensure reliable starting at these 
temperatures, use of an externally powered 
electric engine block heater (available from an 
authorized dealer) is recommended.
AFTER STARTING
The idle speed is controlled automatically, and 
it will decrease as the engine warms up.
STARTING FLUIDS — DIESEL ENGINE 
O
NLY
The engine is equipped with a glow plug 
preheating system. If the instructions in this 
manual are followed, the engine should start in 
all conditions and no type of starting fluid 
should be used.
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the diesel engine is 
operating.
All message center lights are off.
Malfunction Indicator Light (MIL) is off.
Engine Oil Pressure telltale is not illuminated.
Voltmeter operation:
The voltmeter may show a gauge fluctuation at 
various engine temperatures. This is caused by 
the glow plug heating system. The number of 
cycles and the length of the cycling operation is 
controlled by the engine control module. Glow 
plug heater operation can run for several 
minutes, once the heater operation is complete 
the voltmeter needle will stabilize.
COLD WEATHER PRECAUTIONS
Operation in ambient temperature below 32°F 
(0°C) may require special considerations. The 
following charts suggest these options:
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 make 
sure the wireless 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.
WARNING!  (Continued)
21_DT_OM_EN_USC_t.book  Page 146   
Page 149 of 496

STARTING AND OPERATING147
Fuel Operating Range
NOTE:
Use “Ultra Low Sulfur Diesel Fuels (ULSD)”  ONLY.
Fuel Operating Range Chart
*Number 1 ULSD Fuel should only be used where extended arctic conditions below (0°F/-18°C) exist.
4
21_DT_OM_EN_USC_t.book  Page 147   
Page 150 of 496

148STARTING AND OPERATING  
NOTE:
Use of Climatized ULSD Fuel or Number 
1 ULSD Fuel results in a noticeable decrease 
in fuel economy.
Climatized ULSD Fuel is a blend of Number 
2 ULSD and Number 1 ULSD Fuels which 
reduces the temperature at which wax crys -
tals form in fuel.
The fuel grade should be clearly marked on 
the pump at the fuel station.
The engine requires the use of ULSD Fuel. 
Use of incorrect fuel could result in engine 
and exhaust system damage  Ú page 471.
If Climatized or diesel Number 1 ULSD Fuel is 
not available, and you are operating below 
(20°F/-6°C), in sustained arctic conditions, 
Mopar Premium Diesel Fuel Treatment (or 
equivalent) is recommended to avoid gelling 
(see Fuel Operating Range Chart).
Engine Oil Usage
For the correct engine oil viscosity   Úpage 475.
Winter Front Cover
Winter Front Cover
A Winter front or cold weather cover can be 
used in ambient temperatures below 32°F 
(0°C), especially during extended idle 
conditions. This cover is equipped with four 
flaps for managing total grille opening in varying 
ambient temperatures. If a Winter front or cold 
weather cover is to be used the flaps should be 
in the full open position to allow air flow to the 
cooling module and automatic transmission oil 
cooler. When ambient temperatures drop below 
0°F (-17°C) the four flaps need to be closed. A 
suitable cold weather cover is available from a 
Mopar dealer.
Engine Warm-Up
Avoid full throttle operation when the engine is 
cold. When starting a cold engine, bring the 
engine up to operating speed slowly to allow the 
oil pressure to stabilize as the engine warms up.
If temperatures are below 32°F (0°C), operate 
the engine at moderate speeds for five minutes 
before full loads are applied.
ENGINE IDLING
Avoid prolonged idling, long periods of idling 
may be harmful to your engine because 
combustion chamber temperatures can drop so 
low that the fuel may not burn completely. 
Incomplete combustion allows carbon and 
varnish to form on piston rings, cylinder head 
valves, and injector nozzles. Also, the unburned 
fuel can enter the crankcase, diluting the oil 
and causing rapid wear to the engine.
STOPPING THE ENGINE
After full load operation, idle the engine for a 
few minutes before shutting it down. This idle 
period will allow the lubricating oil and coolant 
to carry excess heat away from the 
turbocharger. Refer to the following chart for 
proper engine shutdown.
21_DT_OM_EN_USC_t.book  Page 148