2007 CHEVROLET KODIAK engine

The engine idle speed will return to normal once
the following conditions are met:
•Once engine coolant temperature reaches
about 150°F (65°C).
•The intake temperature reaches a
certain level.
The high idle speed will be temporarily interrupted
and the engine speed will return to normal if
any of the following conditions occur:
•The brake pedal is applied.
•The accelerator pedal is pressed.
•The automatic transmission is shifted out of
PARK (P) or NEUTRAL (N).
•The clutch pedal on the manual transmission
is pressed.
•Vehicle speed is detected.
Once these conditions no longer exist, the engine
idle speed will slowly increase to high idle after
the normal delay, if the conditions for engine
coolant temperature and air intake temperature
are still met.
Engine Checks Before Operating
When you have started your engine, let it run for
20 to 30 seconds before you put a load on the
engine. But do not leave the vehicle while
the engine is running.
Avoid unnecessary idling of diesel engine
equipped vehicles.
If the engine idles too long, the temperature of the
engine coolant will fall below the normal operating
range. Low engine operating temperature
causes several conditions which affect engine
operation and reduce engine life.
The engine should be permitted to go through a
warm-up period. Operate the vehicle at a minimum
of 600 rpm during the warm-up period. During
this period and during operation, the following
observations should be made.
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 175for more information.
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•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 173for 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 169for 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 183for
more information.
•The charging system light should come on
when the ignition key is turned to 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 thegenerator is not charging; it does not reflect
the condition of the battery.) SeeCharging
System Light on page 167for 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 168
for 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.
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Engine Coolant Heater
Your vehicle may be equipped with this feature.
In very cold weather, 0°F (–18°C) or colder,
the engine coolant heater can help. You will 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. At temperatures
above 32°F (0°C), use of the coolant heater is
not required.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Find the plug-in outlet located under the
driver’s door.
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.
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 do
not, it could be damaged.
How long should you keep the coolant heater
plugged in? The answer depends on the outside
temperature, the kind of oil you have, and some
other things. Instead of trying to list everything here,
we ask that you contact your dealer in the area
where you will be parking your vehicle. The dealer
can give you the best advice for that particular area.
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Diesel Engine Exhaust Brake
If your vehicle has a Isuzu 6H or Caterpillar®
Diesel Engine, it may have an exhaust brake,
which is located in the exhaust system.
If your vehicle has a 6.6L DURAMAX
®6600
Diesel Engine, it may have an exhaust brake,
which is controlled through the turbocharger.
The exhaust brake for both engines operates
the same.
The exhaust brake
switch is located in the
instrument panel
switchbank.
Push the bottom of the switch to turn the exhaust
brake on. When you push the top of the switch,
the exhaust brake will turn off.
There is an indicator light on the instrument panel
similar to the symbol on the switch, that will come
on when the exhaust brake is active. SeeExhaust
Brake Indicator Light on page 178for more
information.When using the exhaust brake, the proper gear
range selection is important. The exhaust brake will
be most effective if the gear range selected is the
lowest possible range that does not allow the
engine rpm to go more than 200 rpm above rated
(full load) rpm. If you have a Caterpillar®Diesel
Engine, do not exceed 2900 rpm. If you have a
Isuzu 6H Diesel engine, do not exceed 2550 rpm.
If you have a DURAMAX
®6600 Diesel Engine, do
not exceed 3600 rpm.
If your vehicle has an Allison
®
1000/2200/2300/2500 series automatic
transmission and press this button, the
transmission will downshift to a factory default
setting of third gear. To change the default setting,
or for more information on factory default
settings, contact your dealer for assistance.
The accelerator and clutch pedals must be
released in order for the exhaust brake to engage.
The exhaust brake will automatically shut off
when the anti-lock brake system is active.
If your vehicle has a Caterpillar
®Diesel Engine or
a DURAMAX®6600 Diesel Engine, the exhaust
brake will become active in cruise control
when you exceed the set speed by 3 to 5 mph.
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Two-Speed Rear Axle Electric
Shift Control
If your vehicle has this feature, you will find a label
on the headliner above the windshield or in
another place near the driver that shows how to
use it. Be sure to follow the directions carefully.
Use the following directions based on the type of
shift control the vehicle has.
The rear axle shift
control switch for a
manual transmission
is located on the
shift lever.
When the switch is down, the rear axle is in the
high range. When the switch is up the rear axle is
in low range. Push or pull the switch to change
the range.The two-speed axle control should be in the up
position or low range when you park the vehicle.
You will need to engage the transmission and
move the vehicle a little to assure the axle is in the
low range. Then apply the parking brake, shift
into NEUTRAL and shut off the engine.
Also, always start the vehicle in motion with the
two-speed axle in the low range.
To shift up from low to high, do the following:
1. Move the switch down for the high range.
2. Disengage the clutch.
3. After a brief pause, engage the clutch and
then press down on the accelerator pedal
until the axle engages.
To shift down from high to low, do the following:
1. Release the accelerator and move the
switch upward for low range.
2. Press the accelerator pedal slowly until the
axle engages.
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Air Shift Control (Automatic
Transmission)
The rear axle shift
control switch for an
automatic transmission
is located in the
instrument panel
switchbank.
To use the rear axle shift control, press the bottom
of the switch to get to the high range. The
switch indicator light will come on when the vehicle
is in the high range. Press the top of the switch
to return to the low range.The two-speed axle should be in low range when
you park the vehicle. You will need to engage
the transmission and move the vehicle a little to
assure the axle is in range. Then shift into
PARK (P), apply the parking brake, and shut off
the engine.
To shift up from low to high range while driving,
press the bottom of the rear axle shift control
switch as you are releasing the accelerator pedal.
After the shift has occurred, apply the accelerator
as desired.
To shift from high to low range while driving, press
the top of the rear axle shift control switch as
you release the accelerator pedal. Press the
accelerator pedal slowly until the down shift has
occurred, then apply the accelerator as desired.
For better performance during off-road or under a
heavy load, shift the axle into low range and
then operate the transmission normally.
For better performance on the highway, shift the
axle to high range and operate the transmission
normally.
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Automatic Transmission Operation
We build vehicles with Allison®five and
six-speed automatic transmissions. This part of
the manual covers the basics of these. With these
transmissions, you will find another Allison
®
manual in your vehicle that goes into more detail.
On the headliner, in front of and above the
driver, or in some other place near the driver, you
will see a label that describes important operating
facts about the automatic transmission in your
vehicle. Make sure you follow the instructions on
this label.
Be sure to keep your parking brake set until you
are ready to shift into DRIVE (D), and press
the brake pedal while shifting from NEUTRAL (N)
or PARK (P) to a drive gear.
All vehicles equipped with automatic transmissions
can be started in PARK (P), if equipped, or in
NEUTRAL (N). See the Allison
®Transmission
Operator’s Manual in your vehicle for more
information about this.
{CAUTION:
It can be dangerous to get out of your
vehicle without the parking brake rmly
set. Your vehicle can roll. If you have left
the engine running, the vehicle can move
suddenly. You or others could be injured.
To be sure your vehicle will not move,
even when you are on fairly level ground,
always set the parking brake.
{CAUTION:
Shifting into a drive gear while your
engine is running at high speed is
dangerous. Unless your foot is rmly on
the brake pedal, your vehicle could move
very rapidly. You could lose control and
hit people or objects. Do not shift into a
drive gear while your engine is running at
high speed.
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Overdrive Defeat
If your vehicle has this feature, you can select not
to shift up to fifth gear. This is useful when
towing or under a heavy load.
The overdrive defeat
switch is located in
the instrument panel
to the right of the
steering column.
Press the switch to limit the transmission to
fourth gear. This will allow for fewer downshifts
while pulling a trailer or under a heavy load.
The indicator light in the switch will come on
whenever overdrive defeat is active.
Manual Transmission Operation
Using the Clutch
When you are starting to move the vehicle, it is
important to begin with the engine speed at idle.
Then start to engage the clutch and listen for an
engine speed drop of about 100 rpm. At this point,
the clutch is engaging, so you should increase the
engine speed and fully engage the clutch. It is
important not to increase the engine speed sooner
or before the clutch begins its engagement. If you
do, you can cause damage to your vehicle.
Double-Clutching
You must use the double-clutching method when
you shift an unsynchronized gear set. Disengage
the clutch, shift to NEUTRAL and engage the
clutch. When upshifting, slow the engine until the
engine rpm and road speed match. When
downshifting, accelerate the engine until the
engine rpm and road speed match. Then quickly
disengage the clutch and move the shift lever
to the next gear position and engage the clutch.
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