Cold Weather Starting
If your vehicle has the 6.6L DURAMAX®Diesel Engine
and the Isuzu 6H Diesel Engine, the following notice
applies:
Notice:Your diesel engine has an electric air
intake heater system which reduces white smoke
and helps start the engine in cold weather. Do
not spray starting uid into the air intake where it
can contact the heater elements.
If you do not have the GM Automatic Ether Injection
System, do not use starting uid or you could
damage your engine. If you have the GM system,
use only GM approved starting uid that has
been tested to establish compatibility with the air
inlet heater system.
The following tips will help you get good starting in cold
weather.
•Use the recommended engine oil when the outside
temperature drops below freezing. SeeEngine Oil
(Caterpillar
®Diesel Engine) on page 5-23or
Engine Oil (Gasoline Engine) on page 5-24or
Engine Oil (DURAMAX
®Diesel Engine) on
page 5-28orEngine Oil (Isuzu Diesel Engine) on
page 5-32. When the outside temperature drops
below 0°F (−18°C), use of the optional engine
coolant block heater is recommended.
•If you experience longer cranking times, notice an
unusual amount of exhaust smoke or are at
higher altitudes (over 7,000 ft. or 2 135 m), you may
use your optional engine coolant block heater.
SeeEngine Coolant Heater on page 2-25.
•SeeWhat Fuel to Use on page 5-9for information
on what fuel to use in cold weather.
Cold Weather Starting (Caterpillar®
Diesel)
Because the diesel engine uses compression ignition, it
is harder to start in cold weather than a gasoline
engine. The air intake heater and use of the proper
engine oil, optional engine coolant heaters and optional
ether injection systems help cold weather starting.
See the Caterpillar
®Diesel Engine Operation &
Maintenance Manual for more information.
Restarting the Diesel Engine While
Moving (Automatic Transmission)
If you have to restart the engine while the vehicle is
moving, you will first have to shift to NEUTRAL (N). This
safety feature prevents starting the engine when the
transmission is in a drive gear for more information.
2-16
During this warm-up period, check your warning lights
and gages:
•If oil pressure does not begin to rise within
15 seconds of starting, stop the engine and find the
cause. SeeOil Pressure Gage on page 3-37for
more information.
•If the engine coolant temperature gage needle goes
into the hot area on the gage, stop the engine and
find the cause of the overheating. SeeEngine
Coolant Temperature Gage on page 3-35for more
information.
•If you have air brakes, the dual-needle air pressure
gage should read at least 115 psi (790 kPa) for both
service systems before you try to move the vehicle.
When air pressure is below 60 psi (420 kPa), the
LOW AIR light will come on and you will hear a tone
alarm. SeeBrake System Warning Light on
page 3-32for more information. If the pressure does
not build up or drops during warm-up, stop the
engine and find the cause before you try to move the
vehicle. Recommended air pressure before driving is
120 psi (830 kPa). SeeAir Pressure Gage on
page 3-46for more information.
•The charging system light should come on when the
ignition key is turned to ON/RUN or START and
should go out when the engine is running above idle.
If the light does not go out or comes back on during
normal engine operation, have the charging system
checked right away. (This light tells you if the
generator is not charging; it does not reflect the
condition of the battery.) SeeCharging System Light
on page 3-30for more information.
•The voltmeter charge indicator gage tells you the
condition of your battery’s charge. The gage should
be in the center area during engine operation. The
red area on the left indicates an undercharge
condition; the red area on the right indicates an
overcharge. If the gage is in either red area, have the
battery and charging system checked right away.
SeeVoltmeter Gage on page 3-31for more
information.
Notice:Do not allow the engine to operate at low
idle for more than ve minutes. This can cause
low engine operating temperatures which can affect
engine operation and reduce engine life. Engine
idle speed should be increased to 1200 rpm
whenever extended idle is required. Once started,
the engine should be placed under load to allow the
engine coolant temperature to reach 150°F (66°C)
before shutting off the engine.
2-24
Diesel Engine Fuel
For the Caterpillar®diesel, see the Caterpillar®
Operation & Maintenance Manual for information
concerning fuel usage.
Notice:Diesel fuel or fuel additives not
recommended in this manual could damage the fuel
system and engine. Your warranty would not
cover this damage. And:
Diesel fuel that has been mixed with engine oil
or automatic transmission uid could damage
the engine and emission controls.
We do not test aftermarket diesel fuel additives.
Some additives, particularly those which
contain alcohol or water emulsi ers, could
damage the fuel system. If you believe that
unique circumstances call for a fuel additive to
be used, consult your dealer/retailer for
advice.
If you ever run out of diesel fuel, it can be
difficult to restart the engine. To avoid this,
never let the tank get empty.
If gasoline is ever accidentally added to the fuel
tank, to avoid severe engine damage, do not run the
engine until the fuel tank can be drained.
If you run out of fuel,Running Out of Fuel on page 5-17
tells you how to restart the engine.
What Fuel to Use
Notice:Use of diesel fuel other than Ultra Low
Sulfur Diesel (15 ppm sulfur maximum) or engine oil
other than low ash CJ-4 oil will cause permanent
damage to the DPF and related components. This
damage would not be covered by your warranty.
The emission control system requires the use of diesel
fuel with ultra low-sulfur (0.0015% by weight, or 15 ppm,
maximum) content. Both Ultra Low Sulfur Diesel and Low
Sulfur Diesel fuels are available in the United States and
Ultra Low Sulfur Diesel fuel is available in Canada.
However, only higher sulfur diesel fuel is available
in Mexico.
At a minimum, the diesel fuel you use should meet the
latest version of ASTM specification D 975 (Grades
No. 2-D or No. 1-D S15 commonly known as Ultra Low
Sulfur diesel) in the United States. In addition, the
Engine Manufacturers Association (EMA) has identified
properties of an improved diesel fuel for better engine
performance and durability. Diesel fuels corresponding
to the EMA Recommended Guideline on Premium
Diesel Fuel (FQP-1A) could provide better starting, less
noise, and better vehicle performance. If there are
questions about the fuel you are using, contact your fuel
supplier.
5-9
In the United States, for best results use No. 2-D diesel
fuel year-round (above and below freezing conditions)
as oil companies blend No. 2-D fuel to address climate
differences. No. 1-D diesel fuel can be used in very
cold temperatures (when it stays below 0°F or−18°C);
however, it will produce a power and fuel economy loss.
Avoid the use of No. 1-D diesel fuel in warm or hot
climates. It can result in stalling, poor starting when the
engine is hot, and could damage the fuel injection
system.
It is acceptable to use diesel fuel containing up to
5% biodiesel (B5), but the final blended fuel must meet
the same specification, ASTM D 975 (Grades No. 2-D or
No. 1-D S15 commonly known as Ultra Low Sulfur
diesel), as other fuels used in your vehicle, and the
biodiesel used for making this fuel must meet the latest
version of ASTM specification D 6751. Biodiesel is
produced from vegetable oils or animal fat that have been
chemically modified to reduce the possibility of damage to
the fuel system and engine. Higher concentration (i.e.,
greater than B5) biodiesel-containing fuels or the use of
unmodified bio-oils blended into diesel fuel at any
concentration is not recommended and could damage the
fuel system and engine. Such damage would not be
covered by your warranty. If there are questions about
the biodiesel-containing fuels you are using, contact your
fuel supplier.Because of the cleansing properties of biodiesel,
switching from straight diesel to a biodiesel blend can
prematurely restrict the fuel filter with normal deposits in
the fuel system. A fuel filter replacement might be
required sooner than the recommended interval.
Diesel fuel can foam when you fill the tank. This can
cause the automatic pump nozzle to shut off, even
though the tank is not full. If this happens, just wait for
the foaming to stop and then try filling the tank more
slowly. SeeFilling the Tank on page 5-20.
{CAUTION:
Heat coming from the engine can cause the
fuel to expand and force the fuel out of the
tank. If something ignites the fuel, a re could
start and people could be burned. To help
avoid this, try lling the tank more slowly and
ll the fuel tank only until the automatic nozzle
shuts off. Do not try to top it off.
5-10
What Fuel to Use in Canada
Notice:Use of diesel fuel other than Ultra Low
Sulfur Diesel (15 ppm sulfur maximum) or engine oil
other than low ash CJ-4 oil will cause permanent
damage to the DPF and related components.
This damage would not be covered by your
warranty.
The emission control system requires the use of diesel
fuel with ultra low-sulfur (0.0015% by weight, or 15 ppm,
maximum) content. Both Ultra Low Sulfur Diesel and Low
Sulfur Diesel fuels are available in the United States and
Ultra Low Sulfur Diesel fuel is available in Canada.
However, only higher sulfur diesel fuel is available
in Mexico.
At a minimum, the diesel fuel you use should meet the
latest version of specification CAN/CGSB-3.517 (ULS) in
Canada. In addition, the Engine Manufacturers
Association (EMA) has identified properties of an
improved diesel fuel for better engine performance and
durability (FQP-1A). Diesel fuels corresponding to the
EMA description could provide better starting, less noise,
and better vehicle performance. If there are questions
about the fuel you are using, contact your fuel supplier.Canadian fuels are blended for seasonal changes.
Diesel Type “A” fuel is blended for better cold weather
starting (below 0°F or−18°C); however, you might notice
some power and fuel economy loss. If Type “A” fuel is
used in warmer temperatures, stalling and hard
starting may occur. Diesel Type “B” fuel is blended for
temperatures above 0°F (−18°C).
It is acceptable to use diesel fuel containing up to
5% biodiesel (B5), but the final blended fuel must meet
the same specification, CAN/CGSB-3.517 (ULS) in
Canada, as other fuels used in your vehicle, and the
biodiesel used for making this fuel must meet the latest
version of ASTM specification D 6751. Biodiesel is
produced from vegetable oils or animal fat that have been
chemically modified to reduce the possibility of damage to
the fuel system and engine. Higher concentration (i.e.,
greater than B5) biodiesel-containing fuels or the use of
unmodified bio-oils blended into diesel fuel at any
concentration is not recommended and could damage the
fuel system and engine. Such damage would not be
covered by your warranty. If there are questions about
the biodiesel-containing fuels you are using, contact your
fuel supplier.
5-11
5. Reinstall and tighten the filter container and
reconnect the water sensor wire to the filter.
6. Use the fuel filter priming procedure earlier in this
section to prime the fuel filter.
7. Tighten the air bleed valve by turning it clockwise
until hand-tight.
8. Start your engine and let it idle for five minutes.
Check your fuel filter and air bleed valve for
leaks.
How to Reset Fuel Filter Change
Light - DURAMAX®6.6L (LMM) Engine
The engine controller calculates when to change
the fuel filter based on vehicle and fuel use. Anytime
your fuel filter is changed, reset the fuel filter light so the
engine controller can calculate when the next fuel filter
change is required. If a situation occurs where you
change your fuel filter prior to a change fuel filter light
being turned on, reset the fuel filter change light.To reset the Fuel Filter Change light:
1. Turn the ignition key to RUN with the engine off
2. Fully press the accelerator and brake pedals at the
same time for 10 seconds. If the Fuel Filter Change
light flashes for 5 seconds, the system is resetting.
3. Turn the key to OFF
If the Fuel Filter Change light comes back on when you
start your vehicle, the light has not been reset. Repeat
the procedure. SeeChange Fuel Filter Warning Light on
page 3-44for more information.Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel might be hard
to find. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not be
covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
5-19
When to Add Engine Oil
If the oil is below the cross-hatched area at the tip of
the dipstick, add at least one quart/liter of the
recommended oil. This section explains what kind of oil
to use. For engine oil crankcase capacity, see
Capacities and Specifications on page 5-109.
Notice:Do not add too much oil. If the engine has
so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.The engine oil fill cap is
located near the engine oil
dipstick in the engine
compartment, on the
driver’s side of the vehicle.
Be sure to add enough oil to put the level somewhere in
the proper operating range in the cross-hatched area.
Push the dipstick all the way back in when you are
through.
5-25
Look for this information on the oil container, and use
only those oils that are identified as meeting GM
Standard GM6094M and have the starburst symbol on
the front of the oil container.
Notice:Use only engine oil identi ed as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certi ed For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both provide easier
cold starting and better protection for the engine at
extremely low temperatures.
Engine Oil Additives
Do not add anything to the oil. The recommended oils
with the API service symbol are all you need for
good performance and engine protection.
5-27