2015 Ram 1500 cooling

WARNING!(Continued)
Vehicle.” Follow the warnings under the “Cooling
System Pressure Cap” paragraph.
6. Brake Warning Light This light monitors various brake functions,
including brake fluid level and parking brake
application. If the brake light turns on it may
indicate that the parking brake is applied, that
the brake fluid level is low, or that there is a problem with
the Anti-lock Brake System reservoir.
If the light remains on when the parking brake has been
disengaged, and the fluid level is at the full mark on the
master cylinder reservoir, it indicates a possible brake
hydraulic system malfunction or that a problem with the
Brake Booster has been detected by the Anti-Lock Brake
System (ABS)/Electronic Stability Control (ESC) system.
In this case, the light will remain on until the condition has been corrected. If the problem is related to the brake
booster, the ABS pump will run when applying the brake
and a brake pedal pulsation may be felt during each stop.
The dual brake system provides a reserve braking capac-
ity in the event of a failure to a portion of the hydraulic
system. A leak in either half of the dual brake system is
indicated by the Brake Warning Light, which will turn on
when the brake fluid level in the master cylinder has
dropped below a specified level.
The light will remain on until the cause is corrected.
NOTE:
The light may flash momentarily during sharp
cornering maneuvers, which change fluid level condi-
tions. The vehicle should have service performed, and
the brake fluid level checked.
If brake failure is indicated, immediate repair is neces-
sary.
3
UNDERSTANDING YOUR INSTRUMENT PANEL 167

▫Cooling System Tips — Automatic
Transmission ........................ .225
 ENGINE BLOCK HEATER — IF EQUIPPED . . .227
▫ Block Heater Usage ....................227
 DIESEL EXHAUST BRAKE
(ENGINE BRAKING) ....................227
 AUTOMATIC TRANSMISSION — IF
EQUIPPED .......................... .230
▫ Key Ignition Park Interlock ...............232
▫ Brake/Transmission Shift Interlock System . . .232
▫ Six-Speed Automatic Transmission — If
Equipped .......................... .232
 MANUAL TRANSMISSION — IF EQUIPPED . .244
▫ Shifting ............................ .244▫
Downshifting ....................... .246
▫ Reverse Shifting ..................... .247
 AUXILIARY SWITCHES — IF EQUIPPED .....248
 POWER TAKE OFF OPERATION — IF
EQUIPPED (CHASSIS CAB ONLY) ..........248
▫ Stationary Mode ..................... .249
▫ Mobile Mode ........................ .250
 ENGINE RUNAWAY ....................251
 FUEL REQUIREMENTS ..................252
▫ Fuel Specifications ....................253
▫ Bio-Diesel Fuel Requirements .............254
 ADDING FUEL — 2500/3500 DIESEL
MODELS ........................... .257
 ADDING FUEL — CHASSIS CAB MODELS . . .260
204 STARTING AND OPERATING

diesel engine. However, if seasonably adjusted fuel is
not available and you are operating below 20°F (-6°C),
Mopar® Premium Diesel Fuel Treatment (or equiva-
lent) may be beneficial to avoid fuel gelling.
Engine Oil Usage
Refer to “Maintenance Procedures” in “Maintaining Your
Vehicle” for the correct engine oil viscosity.
Winter Front Usage
A winter front or cold weather cover is to be used in
ambient temperatures below 32°F (0°C), especially dur-
ing extended idle conditions to reduce condensation
build-up within engine crankcase. If a winter front or
cold weather cover is to be used, a percentage of the total
grille opening area must be left uncovered to provide
sufficient air flow to the charge air cooler and automatic
transmission oil cooler. The percentage of opening must
be increased with the increasing ambient air temperature
and/or engine load. If the cooling fan can be heardcycling frequently, increase the size of the opening in the
winter front. A suitable cold weather cover is available
from your MOPAR® dealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0°F (-18°C). For the same de-
crease in temperature, the engine requires twice as much
power to crank at the same RPM. The use of 120 VAC
powered battery blankets will greatly increase starting
capability at low temperatures. Suitable battery blankets
are available from your authorized 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.
220 STARTING AND OPERATING

Operating Precautions
Avoid Overheating The Engine
The temperature of the engine coolant (antifreeze) (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 indi-
cated 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 (antifreeze)
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 combus-
tion which allows carbon and varnish to form on pistonrings 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 — Automatic Transmission
To reduce potential for engine and transmission over-
heating in high ambient temperature conditions, take the
following actions:
•
City Driving —
When stopped, shift the transmission 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.
4
STARTING AND OPERATING 225

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 the torque
converter clutch is inhibited until the transmission fluid
is warm (refer to the “Note” under “Torque Converter
Clutch” in this section). On Pickup models with 68RFE
transmission, top overdrive gear is also inhibited until
the transmission fluid is warm, and during extremely
cold temperatures (-16°F [-27°C] or below), operation
may briefly be limited to first and direct gears only. On
trucks with AS69RC 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), operation may briefly be limited to third gear
only. During this condition, the ability of the vehicle to
238 STARTING AND OPERATING

MAINTAINING YOUR VEHICLE
CONTENTS
ENGINE COMPARTMENT — 6.7L DIESEL —
SIX-SPEED 68RFE (2500/3500 Models) .......277
 ENGINE COMPARTMENT — 6.7L DIESEL —
SIX-SPEED AS69RC HD (3500/CHASSIS CAB
MODELS) ........................... .278
 MAINTENANCE PROCEDURES ...........279
▫ Engine Oil ......................... .280
▫ Engine Air Cleaner Filter ................284
▫ Draining Fuel/Water Separator Filter .......288
▫ Engine Mounted Fuel Filter Replacement .....290
▫ Underbody Mounted Fuel Filter Replacement. .292 ▫
Priming If The Engine Has Run Out Of Fuel . .294
▫ Intervention Regeneration Strategy — Message
Process Flow ....................... .295
▫ Diesel Exhaust Fluid ...................296
▫ Maintenance-Free Batteries ..............297
▫ Cooling System ..................... .298
▫ Charge Air Cooler — Inter-Cooler .........303
▫ Brake System ....................... .304
▫ Clutch Hydraulic System ................305
▫ Transfer Case — If Equipped .............305
6

Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0°F (-18°). For the same de-
crease in temperature, the engine requires twice as much
power to crank at the same RPM. The use of 120 Volt AC
powered battery blankets will greatly increase starting
capability at low temperatures. Suitable battery blankets
are available from your authorized MOPAR® dealer.
Cooling System
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 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.
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
298 MAINTAINING YOUR VEHICLE

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 a
reliable 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
Hybrid Organic Additive Technology (HOAT) en-
gine coolant (antifreeze) or any “globally compat-
ible” coolant (antifreeze). If a non-OAT engine
coolant (antifreeze) is introduced into the cooling
system in an emergency, the cooling system will
need to be drained, flushed, and refilled with fresh
OAT coolant (conforming to MS.90032), by an au-
thorized dealer as soon as possible.
(Continued)
6
MAINTAINING YOUR VEHICLE 299