2020 Ram 3500 Chassis Cab fuel pressure

198STARTING AND OPERATING
Idle-Up Feature
The driver-controlled high idle speed feature will
help increase cylinder temperatures and
provide additional cab heat, however, excessive
idling may still cause the exhaust aftertreat -
ment system to not properly regenerate.
Extended periods of idle time should be
avoided.
The Idle-Up feature uses the Speed Control
switches to increase engine idle speed and
quickly warm the vehicle's interior.

1. With the transmission in PARK, the parking brake applied, and the engine running,
turn on the speed control, then push the
SET switch.

2. The engine RPM will go up to 1,100 RPM. To increase the RPM, push and hold the
ACCEL/RESUME switch and the idle speed
will increase to approximately 1,500 RPM.
To decrease the RPM, push and hold the
DECEL switch and the idle speed will
decrease to approximately 1,100 RPM.
3. To cancel the Idle–Up feature, either push the CANCEL switch, push the ON/OFF
switch, or press the brake pedal.
Noise
Diesel engines can create noises that may
seem as a concern. The nature of a diesel
engine is compression ignition where
compressed air and fuel are mixed and ignited.
Weather, Barometric Pressure, Altitude and
Temperature will affect how fuel is ignited in the
engine. Engine’s will sound different from day to
day or previous model years. Clicking, ticking, or
light knocking is normal and will change from
day to day, as the engine breaks in, and can
vary with changes in ambient temperature, this
is normal. Diesel equipped vehicles also have
an exhaust aftertreatment system to reduce
emissions utilizing a Diesel Particulate Filter
(DPF) and a Selective Reduction Catalyst (SCR).
The SCR reduces Nox using the Diesel Exhaust
Fluid (DEF) system. DEF is injected directly into
the SCR through an dosing module. This
process will create a clicking sound and at
times, will make noise even with the vehicle shut off. This is normal as the DEF dosing
module is purging DEF. Fuel pump noise may
increase during low speed/light load conditions
when ambient temperature is above 100°F
(38°C), and when fuel tank level is below 10%.
This is a normal condition of the fuel system and
controls strategy. If at any time the check
engine light is on, please visit an authorized
dealer.
Stopping The Engine
Idle the engine a few minutes before routine
shutdown. After full load operation, idle the
engine three to five minutes before shutting it
down. This idle period will allow the lubricating
oil and coolant to carry excess heat away from
the combustion chamber, bearings, internal
components, and turbocharger. This is espe
-
cially important for turbocharged, charge
air-cooled engines. Refer to the following chart
for proper engine shutdown:

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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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202STARTING AND OPERATING
ENGINE BREAK-IN RECOMMENDATIONS —
GAS ENGINE
A long break-in period is not required for the
engine and drivetrain (transmission and axle) in
your vehicle.
Drive moderately during the first 300 miles
(500 km). After the initial 60 miles (100 km),
speeds up to 50 or 55 mph (80 or 90 km/h) are
desirable.
While cruising, brief full-throttle acceleration
within the limits of local traffic laws contributes
to a good break-in. Wide-open throttle accelera-
tion in low gear can be detrimental and should
be avoided.
The engine oil installed in the engine at the
factory is a high-quality energy conserving type
lubricant. Oil changes should be consistent with
anticipated climate conditions under which
vehicle operations will occur. For the recom -
mended viscosity and quality grades, refer to
“Fluids And Lubricants” in “Technical Specifica-
tions”. NOTE:
A new engine may consume some oil during its
first few thousand miles (kilometers) of opera
-
tion. This should be considered a normal part of
the break-in and not interpreted as a problem.
Please check your oil level with the engine oil
indicator often during the break in period. Add
oil as required.
ENGINE BREAK-IN RECOMMENDATIONS —
DIESEL ENGINE
The Cummins® Turbo Diesel engine does not
require a break-in period due to its construction.
Normal operation is allowed, providing the
following recommendations are followed:
Warm up the engine before placing it under
load.
Do not operate the engine at idle for
prolonged periods.
Use the appropriate transmission gear to
prevent engine lugging.
Observe vehicle oil pressure and tempera -
ture indicators.
Check the coolant and oil levels frequently.
Vary throttle position at highway speeds
when carrying or towing significant weight.
NOTE:
Light duty operation such as light trailer towing
or no load operation will extend the time before
the engine is at full efficiency. Reduced fuel
economy and power may be seen at this time.
For additional vehicle break-in requirements,
refer to “Trailer Towing” in “Starting And Oper -
ating” of the Owner’s Manual.
Because of the construction of the Cummins®
Turbo Diesel engine, engine run-in is enhanced
by loaded operating conditions which allow the
engine parts to achieve final finish and fit during
the first 6,000 miles (10,000 km).
CAUTION!
Never use Non-Detergent Oil or Straight
Mineral Oil in the engine or damage may
result.

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STARTING AND OPERATING269
REFUELING THE VEHICLE — DIESEL ENGINE
NOTE:
When the fuel nozzle “clicks” or shuts off, the
fuel tank is full.
Tighten the fuel filler cap until you hear a
“clicking” sound. This is an indication that the
fuel filler cap is properly tightened.
Make sure that the fuel filler cap is tightened
each time the vehicle is refueled.
Fuel Filler Cap
If the fuel filler cap is lost or damaged, be sure
the replacement cap is for use with this vehicle.
Avoid Using Contaminated Fuel
Fuel that is contaminated by water or dirt can
cause severe damage to the engine fuel
system. Proper maintenance of the engine fuel
filter and fuel tank is essential. Refer to “Dealer
Service” in “Servicing And Maintenance” for
further information.
Bulk Fuel Storage — Diesel Fuel
If you store quantities of fuel, good mainte -
nance of the stored fuel is also essential. Fuel
contaminated with water will promote the
growth of “microbes.” These microbes form
“slime” that will clog the fuel filtration system
and lines. Drain condensation from the supply
tank and change the line filter on a regular
basis.
NOTE:
When a diesel engine is allowed to run out of
fuel, air is pulled into the fuel system.
If the vehicle will not start, refer to “Priming If
The Engine Has Run Out Of Fuel” in “Servicing
And Maintenance” for further information.CAUTION!
To avoid fuel spillage and overfilling, do not
“top off” the fuel tank after filling.
WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle.
You could be burned. Always place gas
containers on the ground while filling.
WARNING!
Never have any smoking materials lit in or
near the vehicle when the fuel filler cap is
removed or the tank filled.
Never add fuel to the vehicle when the
engine is running.
CAUTION!
Damage to the fuel system or emission
control system could result from using an
improper fuel tank filler tube cap. A poorly
fitting cap could let impurities into the fuel
system.
WARNING!
Do not open the high pressure fuel system
with the engine running. Engine operation
causes high fuel pressure. High pressure fuel
spray can cause serious injury or death.
5

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STARTING AND OPERATING273
VEHICLE LOADING
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your
vehicle including driver, passengers, vehicle,
options and cargo. The label also specifies
maximum capacities of front and rear axle
systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not
exceeded.
Payload
The payload of a vehicle is defined as the allow -
able load weight a truck can carry, including the
weight of the driver, all passengers, options and
cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on
the front and rear axles. The load must be
distributed in the cargo area so that the GAWR
of each axle is not exceeded.
Each axle GAWR is determined by the compo -
nents in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components some -times specified by purchasers for increased
durability does not necessarily increase the
vehicle's GVWR.
Tire Size
The tire size on the Vehicle Certification Label
represents the actual tire size on your vehicle.
Replacement tires must be equal to the load
capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire
size listed.
Inflation Pressure
This is the cold tire inflation pressure for your
vehicle for all loading conditions up to full
GAWR.
Curb Weight
The curb weight of a vehicle is defined as the
total weight of the vehicle with all fluids,
including vehicle fuel, at full capacity condi
-
tions, and with no occupants or cargo loaded
into the vehicle. The front and rear curb weight
values are determined by weighing your vehicle
on a commercial scale before any occupants or
cargo are added.
Loading
The actual total weight and the weight of the
front and rear of your vehicle at the ground can
best be determined by weighing it when it is
loaded and ready for operation.
The entire vehicle should first be weighed on a
commercial scale to ensure that the GVWR has
not been exceeded. The weight on the front and
rear of the vehicle should then be determined
separately to be sure that the load is properly
distributed over the front and rear axles.
Weighing the vehicle may show that the GAWR
of either the front or rear axle has been
exceeded but the total load is within the speci -
fied GVWR. If so, weight must be shifted from
front to rear or rear to front as appropriate until
the specified weight limitations are met. Store
the heavier items down low and be sure that the
weight is distributed equally. Stow all loose
items securely before driving.
Improper weight distributions can have an
adverse effect on the way your vehicle steers
and handles and the way the brakes operate.
5

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310IN CASE OF EMERGENCY
F56 –15 Amp Blue Additional Diesel Content - If Equipped (DS 1500 Only)
F56 –10 Amp Red Fuel Vapor Blocker Valve - If Equipped (HD Only)
F57 –20 Amp Yellow TCM/PCM / Solenoid Trans Pressure SW (RFE Trans Only)
– If Equipped (HD Only)
Transmission (DS 1500 Only)
F58 –10 Amp Red Bed Lighting (LED) – If Equipped (HD Only)
F60 –15 Amp Blue Underhood Lamp / TCM – If Equipped (DS 1500 Only)
F61 –10 Amp RedUREA Sensor / PM Sensor – If Equipped (DS 1500 LD
Diesel & Cummins Diesel)
F62 –10 Amp Red Air Conditioning Clutch
F63 –20 Amp Yellow Ignition Coils (Gas), Ignition Coils Capacitors (Gas) / Short
Runner Valve Actuator / Urea Heater Control Unit (DS
1500 LD Diesel) / RLY Coil Feed-SCR (DS 1500 LD Diesel)
F64 –25 Amp ClearFuel Injectors / Powertrain Control Module / SRV – If
Equipped
F65 –10 Amp RedMOD Inverter (Wake Up) / Power Port / USB IP / WCPM –
If Equipped (HD Only)
Spare (DS 1500 Only)
F66 –10 Amp RedSunroof / Light and Rain Sensor Module / Inside Rearview
Mirror / Passenger Window SW / USB Port Rear / Feed for
R/A RLY #2 Coil – If Equipped
F67 –10 Amp RedCD / DVD / UCI Port – If Equipped (HD Only)
Bluetooth Hands-Free Module / CD – If Equipped (DS
1500 Only)
Cavity
Cartridge Fuse Micro Fuse Description

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329
SERVICING AND MAINTENANCE
SCHEDULED SERVICING — GAS ENGINE
Your vehicle is equipped with an automatic oil
change indicator system. The oil change indi-
cator system will remind you that it is time to
take your vehicle in for scheduled maintenance.
Based on engine operation conditions, the oil
change indicator message will illuminate. This
means that service is required for your vehicle.
Operating conditions such as frequent
short-trips, trailer tow, extremely hot or cold
ambient temperatures, and E85 fuel usage will
influence when the “Oil Change Required”
message is displayed. Severe Operating Condi-
tions can cause the change oil message to illu -
minate as early as 3,500 miles (5,600 km)
since last reset. Have your vehicle serviced as
soon as possible, within the next 500 miles
(805 km). An authorized dealer will reset the oil change
indicator message after completing the sched
-
uled oil change. If a scheduled oil change is
performed by someone other than an autho -
rized dealer, the message can be reset by refer -
ring to the steps described under “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel” for further information.
Gas Engines:
Under no circumstances should oil change
intervals exceed 8,000 miles (13,000 km),
12 months or 350 hours of engine run time,
whichever comes first. The 350 hours of engine
run or idle time is generally only a concern for
fleet customers.
Severe Duty:
Change Engine Oil at 4,000 miles (6,500 km) or
350 hours of engine run time if the vehicle is
operated in a dusty and off road environment or
is operated predominately at idle or very low
engine RPM. This type of vehicle use is consid -
ered Severe Duty. Once A Month Or Before A Long Trip:Check engine oil level.
Check windshield washer fluid level.
Check the tire inflation pressures and look
for unusual wear or damage. Rotate at the
first sign of irregular wear.
Check the fluid levels of the coolant reservoir,
brake master cylinder, power steering and
automatic transmission (six-speed only), and
fill as needed.
Check function of all interior and exterior
lights.
7

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SERVICING AND MAINTENANCE345
Checking Oil Level — Gas Engine
To ensure proper lubrication of your vehicle's
engine, the engine oil must be maintained at
the correct level. Check the oil level at regular
intervals, such as every fuel stop. The best time
to check the engine oil level is about five
minutes after a fully warmed up engine is shut
off.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil level
readings. Always maintain the oil level within
the SAFE zone on the dipstick. Adding one quart
of oil when the reading is at the bottom of the
SAFE zone will result in a reading at the top of
the safe zone on these engines.
Checking Oil Level — Diesel Engine
To ensure proper lubrication of your vehicle's
engine, the engine oil must be maintained at
the correct level. Check the oil level at regular
intervals. The best time to check the oil level is
before starting the engine after it has been parked overnight. When checking oil after oper
-
ating the engine, first ensure the engine is at full
operating temperature, then wait for
30 minutes after engine shutdown to check the
oil.

Engine Oil Dipstick

Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil level
readings. Add oil only when the level on the
dipstick is below the “ADD” mark. The total
capacity from the ADD mark to the Full mark is
2 Quarts (1.9Liters). Never operate the engine with oil level below
the “ADD” mark or above the upper “SAFE”
mark.
Adding Washer Fluid
The fluid reservoir is located under the hood
and should be checked for fluid level at regular
intervals. Fill the reservoir with windshield
washer solvent only (not radiator antifreeze).
When refilling the washer fluid reservoir, take
some washer fluid and apply it to a cloth or
towel and wipe the wiper blades clean. This will
help blade performance.
To prevent freeze-up of your windshield washer
system in cold weather, select a solution or
mixture that meets or exceeds the temperature
range of your climate. This rating information
can be found on most washer fluid containers.
CAUTION!
Overfilling or underfilling will cause oil
aeration or loss of oil pressure. This could
damage your engine.
1 — ADD Range
2 — Full Mark
3 — SAFE Range
CAUTION!
Overfilling or underfilling the crankcase will
cause oil aeration or loss of oil pressure. This
could damage your engine.
7

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