2007 Ram 2500 (Diesel) engine

Although your vehicle will usually be drivable and not
need towing, see your dealer for service as soon as
possible.
CAUTION!
Prolonged driving with the MIL on could cause
damage to the engine control system. It also could
affect fuel economy and driveability.
If the MIL is flashing, severe catalytic converter
damage and power loss will soon occur. Immediate
service is required.
19. Brake System Warning Light
This light illuminates when the ignition key is turned to
the ON position and remains on for a few seconds. If the
light stays on longer, it may be an indication that the
parking brake has not been released. This light willilluminate if the brake fluid is low, especially when
braking or accelerating hard. This light will illuminate if
the ABS indicator light has a malfunction. This light will
flash if the engine is running and the parking brake is on.
If the light remains on when the parking brake is
released, it indicates a possible brake hydraulic system
malfunction. In this case, the light will remain on until
the cause is corrected.
If brake failure is indicated, immediate repair is necessary
and continued operation of the vehicle in this condition is
dangerous.
Acceleration which causes the rear wheels to slip for a
period of time may result in the red brake light illumi-
nating and a brake switch code being set on ABS
equipped vehicles. Depressing the brake pedal should
extinguish the red brake light.
UNDERSTANDING YOUR INSTRUMENT PANEL 203
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20. ABS Warning Light
This light monitors the Anti-Lock Brake System
which is described elsewhere in this manual. This
light will come on when the ignition key is turned to the
ON position and may stay on for five seconds. If the ABS
light remains on or comes on during driving, it indicates
that the anti-lock portion of the brake system is not
functioning and that service is required. See your autho-
rized dealer immediately. The ABS light could also
illuminate during loss of traction and remain illuminated
until the brake pedal is pressed.
21. Cargo Light
The Cargo Lamp light will illuminate when the
Cargo Lamp is activated by pressing the Cargo
Light Button on the headlight switch.22. Electronic Throttle Control (ETC)
This light informs you of a problem with the
Electronic Throttle Control system. If a prob-
lem is detected the light will come on while the
engine is running. If the light remains lit with
the engine running your vehicle will usually be drivable,
however, see your dealer for service as soon as possible.
If the light is flashing when the engine is running,
immediate service is required and you may experience
reduced performance, an elevated/rough idle or engine
stall and your vehicle may require towing. The light will
come on when the ignition is first turned on and remain
on for 15 seconds as a bulb check. If the light does not
come on during starting, have the system checked by an
authorized dealer.
204 UNDERSTANDING YOUR INSTRUMENT PANEL

23. SERV 4WD Indicator
The 4WD indicator will be illuminated whenever the
4WD mode is engaged for either the manual or electric
shift 4WD systems. The SERV 4WD indicator monitors
the electric shift 4WD system. If the SERV 4WD light
stays on or comes on during driving, it means that the
4WD system is not functioning properly and that service
is required.
24. Water In Fuel Indicator
Indicates there is water detected in the fuel
filter. Refer to the Maintenance section, Drain-
ing Fuel/Water Separator Filter, for water
drain procedure. (See page 427 for more information.)
25. Transmission Oil Temperature Warning Light
(Automatic Transmissions Only)
This light indicates that there is excessive trans-
mission fluid temperature that might occur
with severe usage such as trailer towing. It mayalso occur when operating the vehicle in a high torque
converter slip condition, such as 4-wheel-drive operation
(e.g. snow plowing, off- road operation). If this light
comes on, stop the vehicle and run the engine at idle or
faster, with the transmission in NEUTRAL until the light
goes off.
26. Wait To Start Indicator
The Wait To Start Indicator will illuminate when
the ignition is turned to the run position and the
intake manifold temperature is below 66 degrees F.
Follow engine starting procedure for proper engine start-
ing and operating. Wait until the Wait To Start Indicator
turns OFF then start the vehicle.
NOTE:The Wait To Start Indicator may not illuminate if
the engine coolant temperature is warm enough.
UNDERSTANDING YOUR INSTRUMENT PANEL 205
4

snowflake button shows that the air conditioning is on.
Press the button a second time to turn the air condition-
ing off.
Slight changes in engine speed or power may be noticed
when the air conditioning compressor is on. This is a
normal occurrence as the compressor will cycle on and
off to maintain comfort and increase fuel economy.
The mode control (at the right of the
control panel) can be set in any of the
following positions:
NOTE:To improve your selection choices, the system
allows you to operate at intermediate positions between
the major modes. These intermediate positions are iden-
tified by the small dots.Recirculation Modes (Panel or Bi-Level)
Select the recirculation modes when
the outside air contains smoke, odors,
high humidity, or if rapid cooling is
desired. This feature allows for recir-
culation of interior air only. Air flows
through the panel only or through
both the panel and floor vents depend-
ing on the selected mode (panel vs bi-level).
NOTE:Selecting a “Recirculation Mode” mode does not
necessarily consume more fuel than normal A/C mode.
Panel
Outside air flows through the outlets located in the
instrument panel.
Bi-Level
Outside air flows through the outlets located in the
instrument panel and at the floor.
260 UNDERSTANDING YOUR INSTRUMENT PANEL

Circulation
The cab is designed with features to promote outside air
circulation. There are grilles in the cab back panel. These
are air exhausters that provide the means for regular
exchange of cab air.
Side window demisters direct air flow specifically to the
window glass to help prevent interior fogging of the
glass. They are located in the extreme outside upper
edges of the instrument panel. The demisters also pro-
vide extra air ducts for circulation. They are in operation
whenever the Floor, Mix or Defrost modes are in use. To
remove frost from the side windows, it is best to use the
full defrost mode.
NOTE:When you turn off the engine you may hear a
hissing sound from under the hood for a short period of
time. This is a normal condition that occurs if the air
conditioning system has been on. It is not an indication of
a problem with the air conditioning system.
Air Conditioning with Dual Zone Temperature
Control — If Equipped
With the Dual Zone Temperature Control System, each
front seat occupant can independently control the tem-
perature of air coming from the outlets on their side of
the vehicle.
Dual Zone Control Head
262 UNDERSTANDING YOUR INSTRUMENT PANEL

Circulation
The cab is designed with features to promote outside air
circulation. There are grilles in the cab back panel. These
are air exhausters that provide the means for regular
exchange of cab air.
Side window demisters direct air flow specifically to the
window glass to help prevent interior fogging of the
glass. They are located in the extreme outside upper
edges of the instrument panel. The demisters also pro-
vide extra air ducts for circulation. They are in operation
whenever the Floor, Mix or Defrost modes are in use.
NOTE:When you turn off the engine you may hear a
hissing sound from under the hood for a short period of
time. This is a normal condition that occurs if the air
conditioning system has been on. It is not an indication of
a problem with the air conditioning system.
Rear Air Duct—Mega Cab Only
The rear seat will receive air flow in all modes except for
Defrost.
The rear air duct is designed to be pointed up when in
A/C mode, and pointed down in Heat mode.
Mega Cab Rear Air Duct
266 UNDERSTANDING YOUR INSTRUMENT PANEL

Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Recommended
Fluids and Genuine Parts for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
NEUTRAL and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.NOTE:On models equipped with Diesel engines, the
idle speed will automatically increase to 1000 rpm at
elevated coolant temperatures to improve engine cooling.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.
Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
268 UNDERSTANDING YOUR INSTRUMENT PANEL

STARTING AND OPERATING
CONTENTS

Starting Procedures – Diesel Engines.........275
▫Manual Transmission – If Equipped........275
▫Automatic Transmission – If Equipped......276
▫Normal Starting Procedure — Engine Manifold
Airtemperature Above 66°F (19°C).........276
▫Starting Procedure — Engine Manifold Air
Temperature Below 66°F (19°C)...........277
▫Starting Fluids.......................281

Normal Operation (Diesel Engine)...........281▫Cold Weather Precautions...............282
▫Engine Idling — In Cold Weather..........286
▫Stopping The Engine...................287
▫Engine Speed Control..................288
▫Operating Precautions..................288
▫Cooling System Tips —
Automatic Transmission................288

Diesel Exhaust Brake (Engine Braking) –
If Equipped...........................290
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