COOLING SYSTEM Ram 2500 2016 User Guide

Autostop, the Climate Controls system may automati-
cally adjust airflow to maintain cabin comfort. Customer
settings will be maintained upon return to an engine
running condition.
Possible Reasons The Engine Does Not Autostop
Prior to engine shut down, the system will check many
safety and comfort conditions to see if they are fulfilled.
In following situations, the engine will not stop:
•Driver ’s seat belt is not buckled.
• Driver ’s door is not closed.
• Outside temperature is less than 1°F (–17°C) or greater
than 104°F (40°C).
• Battery temperature too warm or cold.
• The vehicle is on a steep grade. •
Cabin heating or cooling is in process and an accept-
able cabin temperature has not been achieved.
• HVAC is set to full defrost mode at a high blower
speed.
• Engine has not reached normal operating temperature.
• Battery discharged.
• The transmission is not in DRIVE.
• Hood is open.
• Vehicle is in 4LO transfer case mode.
Other factors which can inhibit AutoStop include: fuel
level, accelerator pedal input, engine temp too high and
steering angle.
It may be possible for the vehicle to be driven several
times without the STOP/START system going into a
STOP/START READY state under more extreme condi-
tions of the items listed above.
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STARTING AND OPERATING 483

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
temperature as well as vehicle speed. This feature im-
proves warm up time of the engine and transmission to
achieve maximum efficiency. Engagement of both the
torque converter clutch and the top overdrive gear are
inhibited until the transmission fluid is warm (refer to the
“Note” under “Torque Converter Clutch” in this section).
During extremely cold temperatures (-16°F [-27°C] or
below), operation may briefly be limited to first and direct gears only. 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 direct gear regardless of which forward gear is se-
lected. 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 dam-
aging the transmission.
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.
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STARTING AND OPERATING 505

If the transmission temperature exceeds normal operat-
ing limits, the powertrain controller will modify the
transmission 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.
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
temperature as well as vehicle speed. This feature im-
proves warm up time of the engine and transmission to
achieve maximum efficiency. Engagement of both the
torque converter clutch and the top overdrive gear are
inhibited until the transmission fluid is warm (refer to the
“Note” under “Torque Converter Clutch” in this section).
During extremely cold temperatures (-16°F [-27°C] or
below), operation may briefly be limited to first and
direct gears only. 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 fourth gear regardless of which forward gear is
5
STARTING AND OPERATING 517

crossing is the water depth, current and bottom con-
ditions. On soft bottoms the vehicle will sink in,
effectively increasing the water level on the vehicle. Be
sure to consider this when determining the depth and
the ability to safely cross.
• Crossing Puddles, Pools, Flooded Areas Or Other
Standing Water – Puddles, pools, flooded or other
standing water areas normally contain murky or
muddy waters. These water types normally contain
hidden obstacles and make it difficult to determine an
accurate water depth, approach angle, and bottom
condition. Murky or muddy water holes are where
you want to hook up tow straps prior to entering. This
makes for a faster, cleaner and easier vehicle recovery.
If you are able to determine you can safely cross, than
proceed using the low and slow method.CAUTION!
Muddy waters can reduce the cooling system effec-
tiveness by depositing debris onto the radiator.
• Crossing Ditches, Streams, Shallow Rivers Or Other
Flowing Water – Flowing water can be extremely
dangerous. Never attempt to cross a fast running
stream or river even in shallow water. Fast moving
water can easily push your vehicle downstream
sweeping it out of control. Even in very shallow water,
a high current can still wash the dirt out from around
your tires putting you and your vehicle in jeopardy.
There is still a high risk of personal injury and vehicle
damage with slower water currents in depths greater
than the vehicle’s running ground clearance. You
should never attempt to cross flowing water which is
deeper than the vehicle’s running ground clearance.
Even the slowest current can push the heaviest vehicle
582 STARTING AND OPERATING

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 trans-
mission fluid and filter(s) as specified forpolice, taxi,
fleet, or frequent trailer towing. Refer to the “Mainte-
nance Schedule” for the proper maintenance intervals.
NOTE: Check the automatic transmission fluid level
before towing (6-speed automatic only).
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.
Electronic Speed Control — If Equipped
• Do not use in 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 over-
heating, take the following actions:
City Driving
When stopped for short periods of time, shift the trans-
mission into NEUTRAL and increase engine idle speed.
Highway Driving
Reduce speed.
710 STARTING AND OPERATING

HAZARD WARNING FLASHERS
The Hazard Warning flasher switch is located on the
upper switch bank just below the radio.Push the switch to turn on the Hazard Warning
flasher. When the switch is activated, all direc-
tional turn signals will flash on and off to warn oncoming
traffic of an emergency. Push the switch a second time to
turn off the Hazard Warning flashers.
This is an emergency warning system and it should not
be used when the vehicle is in motion. Use it when your
vehicle is disabled and it is creating a safety hazard for
other motorists.
When you must leave the vehicle to seek assistance, the
Hazard Warning flashers will continue to operate even
though the ignition is placed in the OFF position.
NOTE: With extended use the Hazard Warning flashers
may wear down your battery.
IF YOUR ENGINE OVERHEATS
In any of the following situations, you can reduce the
potential for overheating by taking the appropriate ac-
tion.
• 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.
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WHAT TO DO IN EMERGENCIES 727

•You can also turn the temperature control to maximum
heat, the mode control to floor and the blower control
to high. This allows the heater core to act as a
supplement to the radiator and aids in removing heat
from the engine cooling system.
CAUTION!
Driving with a hot cooling system could damage
your vehicle. If the temperature gauge reads HOT
(H), pull over and stop the vehicle. Idle the vehicle
with the air conditioner turned off until the pointer
drops back into the normal range. If the pointer
remains on HOT (H), and you hear continuous
chimes, turn the engine off immediately and call for
service.
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator. If
you see or hear steam coming from under the hood,
do not open the hood until the radiator has had time
to cool. Never try to open a cooling system pressure
cap when the radiator or coolant bottle is hot.
WHEEL AND TIRE TORQUE SPECIFICATIONS
Proper lug nut/bolt torque is very important to ensure
that the wheel is properly mounted to the vehicle. Any
time a wheel has been removed and reinstalled on the
vehicle the lug nuts/bolts should be torqued using a
properly calibrated torque wrench.
728 WHAT TO DO IN EMERGENCIES

▫Body Lubrication .....................811
▫ Windshield Wiper Blades ...............812
▫ Adding Washer Fluid ..................815
▫ Exhaust System ..................... .816
▫ Cooling System ..................... .818
▫ Brake System ....................... .825
▫ Rear Axle And 4x4 Front Driving Axle Fluid
Level ............................. .827
▫ Transfer Case ....................... .829
▫ Automatic Transmission ................829
▫ Appearance Care And Protection From
Corrosion .......................... .833
 FUSES ............................. .841
▫ Power Distribution Center ...............842
VEHICLE STORAGE ....................851
 REPLACEMENT BULBS .................852
 BULB REPLACEMENT ..................854
▫ Base Quad / Premium Bi-Halogen: Low Beam
Headlamp, High Beam Headlamp, Front Park
And Turn — If Equipped ...............854
▫ Fog Lamps — If Equipped ..............856
▫ Rear Tail/Stop, Turn Signal And Backup
Lamps ............................ .857
▫ Center High-Mounted Stoplamp (CHMSL) With
Cargo Lamp ........................ .858
▫ Cab Top Clearance Lamps — If Equipped . . . .860
▫ Rear Lamp Bar ID Marker (Dual Rear Wheels) —
If Equipped ......................... .862
788 MAINTAINING YOUR VEHICLE

To minimize the possibility of catalytic converter damage:
•Do not shut off the engine or interrupt the ignition,
when the transmission is in gear and the vehicle is in
motion.
• Do not try to start the engine by pushing or towing the
vehicle.
• Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough
idle or malfunctioning operating conditions.
Cooling System
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator. If
(Continued)
WARNING! (Continued)
you see or hear steam coming from under the hood,
do not open the hood until the radiator has had time
to cool. Never try to open a cooling system pressure
cap when the radiator is hot.
Engine Coolant Checks
Check the engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
applicable). If the engine coolant (antifreeze) is dirty or
rusty in appearance, the system should be drained,
flushed and refilled with fresh coolant. Check the front of
the A/C condenser (if equipped) or radiator for any
accumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the A/C condenser (if equipped) or the back of the
radiator core.
818 MAINTAINING YOUR VEHICLE

Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts and tightness of the connection at the
coolant recovery bottle and radiator. Inspect the entire
system for leaks.
With the engine at normal operating temperature (but
not running), check the cooling system pressure cap for
proper vacuum sealing by draining a small amount of
engine coolant (antifreeze) from the radiator drain cock.
The radiator drain cock is located in the lower radiator
tank. If the cap is sealing properly, the engine coolant
(antifreeze) will begin to drain from the coolant expan-
sion bottle. DO NOT REMOVE THE COOLANT PRES-
SURE CAP WHEN THE COOLING SYSTEM IS HOT.
Cooling System — Drain Flush And Refill
If the engine coolant (antifreeze) is dirty or contains a
considerable amount of sediment, clean and flush with areliable cooling system cleaner. Follow with a thorough
rinsing to remove all deposits and chemicals. Properly
dispose of old engine coolant (antifreeze).
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
Selection Of Coolant
Refer to “Fluids, Lubricants, And Genuine Parts” in
“Maintaining Your Vehicle” for further information.
CAUTION!
•
Mixing of engine coolant (antifreeze) other than
specified Organic Additive Technology (OAT) en-
gine coolant (antifreeze), may result in engine
damage and may decrease corrosion protection.
Organic Additive Technology (OAT) engine cool-
ant is different and should not be mixed with
(Continued)
7
MAINTAINING YOUR VEHICLE 819