Page 10 of 100
Fuel Operated Heater (FOH)
(Van Models Only)
If your vehicle includes a fuel operated heater (FOH),
it will enhance heater performance and will reduce the
amount of time it takes to warm the inside of your vehicle
in cold conditions below 40°F (4.4°C). The fuel operated
heater is installed in the frame rail on the driver’s side of
the vehicle and uses diesel to warm up the engine
coolant, which finally warms up the passenger’s cabin
air. The FOH works automatically, depending on the
fuel level, engine coolant temperature and outside air
temperature. It works only with the engine running.
Engine Coolant Heater
In very cold weather, 0°F (−18°C) or colder, the engine
coolant heater can help. You’ll get easier starting
and better fuel economy during engine warm-up.
Usually, the coolant heater should be plugged in a
minimum of four hours prior to starting your vehicle.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located in the engine compartment,
on the passenger’s side of the vehicle, near the
right side engine mount.
3. Plug it into a normal, grounded 110-volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously injured.
Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord
will not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
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Page 11 of 100
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you don’t, it could
be damaged.
How long should you keep the coolant heater plugged in?
The answer depends on the outside temperature. You
may wish to use your coolant heater to improve ease
of starting at temperatures between 0°F (−18°C)
and−20°F (−29°C).Keep the coolant heater plugged in for
a minimum of four hours. At temperatures below−20°F
(−29°C), the coolant heater should remain plugged in for
at least eight hours. It will not harm either the coolant
heater or the vehicle to leave the coolant heater plugged
in longer than the times stated. Be sure to remove and
store the cord before starting the engine. SeeDiesel
Fuel Requirements and Fuel System on page 5-2for
information on what fuel to use in cold weather.
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Page 13 of 100
Warning Lights, Gages and Indicators...............3-2
Instrument Panel Cluster.................................3-2
Malfunction Indicator Lamp..............................3-4
Oil Pressure Gage..........................................3-6
Wait to Start Light..........................................3-7Reduced Engine Power Light (Van Models Only) . . .3-7
Fuel Gage.....................................................3-8
Water in Fuel Warning Light (Van Models Only).....3-9
Driver Information Center (DIC)
(Pickup Models Only)....................................3-9
Section 3 Instrument Panel
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Page 16 of 100
Malfunction Indicator Lamp
Check Engine Light
Your vehicle has a computer which monitors operation
of the fuel, timing, and emission control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the life
of the vehicle, helping to produce a cleaner environment.The check engine light comes on to indicate when service
is required. Malfunctions often will be indicated by the
system before any problem is apparent. This may prevent
more serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls may not
work as well, your fuel economy may not be as good,
and your engine may not run as smoothly. This could
lead to costly repairs that may not be covered by
your warranty.
Notice:Modi cations made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modi cations to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test. Pickup Models
Van Models
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Page 17 of 100
If the Light Comes On
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is not
running. If it does not, have it repaired. This light will also
come on if an emission control system malfunction has
been detected on your vehicle. Diagnosis and service
may be required.
You also may be able to correct the emission system
malfunction by considering the following:
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
Are you low on fuel?
As your engine starts to run out of fuel, your engine may
not run as efficiently as designed since small amounts of
air are sucked into the fuel line. The system can detect
this. Adding fuel should correct this condition. It will take
a few driving trips to turn the light off.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has the
proper test equipment and diagnostic tools to fix any
mechanical or electrical problems that may have
developed.
Emissions Inspection and
Maintenance Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this inspection
could prevent you from getting a vehicle registration.
Here are some things you need to know in order to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the check
engine light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your battery
has run down. The diagnostic system is designed to
evaluate critical emission control systems during normal
driving. This may take several days of routine driving. If
you have done this and your vehicle still does not pass
the inspection for lack of OBD system readiness, your
GM dealer can prepare the vehicle for inspection.
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Page 18 of 100
Oil Pressure GageThe oil pressure gage shows the engine oil pressure in
psi (pounds per square inch) when the engine is running.
Canadian vehicles indicate pressure in kPa (kilopascals).
Oil pressure may vary under different driving conditions
and oil types. The DURAMAX
®engine may generate
oil pressure in excess of 80 psi (548 kPa) under certain
conditions, especially in cold temperatures. This is a
normal operating range.
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be covered
by your warranty. Always follow the maintenance
schedule in this manual for changing engine oil. United States
(Pickup Models)Canada
(Pickup Models)
United States
(Van Models)Canada
(Van Models)
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Page 19 of 100
Wait to Start Light
Your diesel engine has a
glow plug system to aid in
starting your vehicle.
For pickup models, this light shows that the system is
functioning properly and tells you when the engine is
ready to be started. For van models, an instrument panel
WAIT TO START indicator light shows that the system
is functioning properly and tells you when the engine is
ready to be started.
Your vehicle has a fast warm-up glow plug system. The
wait to start light will illuminate for a considerably shorter
time than most diesel engines due to the rapid heating of
the glow plug system.
For more information, seeStarting the Diesel Engine
on page 2-2.
Reduced Engine Power Light
(Van Models Only)
If the reduced engine
power light comes on
while you are driving, the
computer is indicating that
your vehicle has a problem.
You should take your
vehicle in for service soon.
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Page 21 of 100
Water in Fuel Warning Light
(Van Models Only)
The light will come on to
warn you if there is water
in the diesel fuel system.
For more information on how this light works, seeDiesel
Fuel Requirements and Fuel System on page 5-2.
Driver Information Center (DIC)
(Pickup Models Only)
The Driver Information Center (DIC) is located on the
instrument panel cluster above the steering wheel. The
DIC comes on when the ignition is on. After a short delay
the DIC will display the current driver and the information
that was last displayed before the engine was last
turned off.
If a problem is detected, a warning message will appear
on the display. Pressing the select button on the DIC
steering wheel buttons, or the trip odometer reset stem
for vehicles without DIC steering wheel buttons, will
acknowledge some current warning or service messages.Some messages that your DURAMAX
®diesel may
show are:
ELEVATED IDLE OFF
This message will appear when the elevated
idle/exhaust restrictor feature has been turned off. For
more information on the elevated idle/exhaust restrictor
feature, seeStarting the Diesel Engine on page 2-2.
ELEVATED IDLE ON
This message will appear when the elevated
idle/exhaust restrictor feature has been turned on. For
more information on the elevated idle/exhaust restrictor
feature, seeStarting the Diesel Engine on page 2-2.
REDUCED ENGINE POWER
A computer monitors the operation of the electric
accelerator. If the REDUCED ENGINE POWER
message comes on while you are driving, the computer
is indicating that your vehicle has a problem. You
should take your vehicle in for service soon.
WATER IN FUEL
This message will come on to warn you if there is water in
the diesel fuel system. For more information on how this
message works, seeDiesel Fuel Requirements and Fuel
System on page 5-2.
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