Gasoline Engine Warm-Up
When you’ve started your engine, let it run for
20 or 30 seconds to warm up before you put a load on
the engine.
Drive at moderate speeds for the first few miles,
especially in cold weather. Running a cold engine at
high speed can damage it. SeeHigh Idle Systemunder
Starting Your Diesel Engine on page 2-14
Restarting the Gasoline Engine While
Moving (Automatic Transmission)
If you have to restart the engine while the vehicle is
moving, you’ll first have to shift the automatic
transmission to NEUTRAL (N). This safety feature
prevents starting the engine when the transmission is in
a drive gear.
Stopping the Gasoline Engine
Let your engine idle for a few seconds before turning it
off after you have finished driving your vehicle.
If you shift to NEUTRAL (N) or PARK (P), set the
parking brake.
If your vehicle has a two-speed axle, put the range
selector in LOW. To be sure the axle has shifted into
LOW, engage the clutch and transmission; the vehicle
may move slightly when you do this.While your engine is idling before you turn it off, you
can make a list of any operational or handling concerns
to give to responsible maintenance personnel so
they can handle them right away.
Moisture will condense in a fuel tank that is almost
empty if the engine has not run for a while, even just
overnight under some conditions. So, it’s always best to
refuel your vehicle at the end of each run.
Starting Your Diesel Engine
If you have a Caterpillar®diesel engine, also refer to
your Caterpillar®Diesel Engine Operation &
Maintenance Manual for starting procedure.
For vehicles with the DURAMAX™ diesel engine, also
seeStarting Your DURAMAX™ Diesel Engine on
page 2-19.
To make starting easier in cold weather (below 32°F or
0°C), the proper viscosity engine oil should be used.
SeeEngine Oil (Caterpillar
®Diesel Engine) on
page 5-20orEngine Oil (Gasoline Engine) on page 5-20
orEngine Oil (DURAMAX™ Diesel) on page 5-25. It’s
also best to heat the engine oil first. You can do this by
using an engine coolant heater.
If you ever need to have your vehicle towed, see
Towing Your Vehicle on page 4-31.
2-14
Restarting the Diesel Engine While
Moving (Automatic Transmission)
If you have to restart the engine while the vehicle is
moving, you’ll first have to shift the automatic
transmission to NEUTRAL (N). This safety feature
prevents starting the engine when the transmission is in
a drive gear.
Stopping the Diesel Engine
If you have a Caterpillar®diesel engine, see your
Caterpillar®Diesel Engine Operation & Maintenance
Manual.
1. Set the parking brake and shift to NEUTRAL (N) or
PARK (P).
2. Turn the ignition key to OFF.
If your vehicle has a two-speed axle, see
Two-Speed Rear Axle Electric Shift Control on
page 2-26.
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.
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.
2-15
Diesel Engine Warm-Up
Several factors affect how quickly your diesel engine
warms up. These can include outside temperature,
engine load, idle time and your vehicle’s option content.
Your vehicle may be equipped with some features
that can help the engine reach operating temperature
sooner. Some of these features are discussed below.
Also, remember that an automatic transmission
adds heat to the cooling system through the heat
exchanger in the radiator. Because of this, vehicles
equipped with automatic transmissions are often able to
retain engine coolant heat better than manual
transmission vehicles.
See your Caterpillar
®Operation & Maintenance manual
for additional diesel engine warm-up information.
Engine Alarm and Automatic Shutdown
Your check gages light will come on if the system
senses high engine temperature or low engine oil
pressure. If high engine temperature or low engine oil
pressure is detected, you will also hear a tone alarm at
two beats per second. The alarm and the light will
remain on until the condition is fixed. If the engine
temperature or oil pressure condition worsens, the tone
alarm will go to five beats per second.If the system senses low engine coolant, the five beat
per second alarm and the low coolant warning light
will come on.
The five beats per second tone alarm means that your
engine will shut down in about 25–30 seconds.
There is also an engine shutdown light to indicate that
the engine will shut down. SeeEngine Shutdown
Warning Light on page 3-39.
Pull off the road and shut off the engine. Don’t start it
until the reason for the problem is known, and the
problem is fixed. If the engine shuts down when you are
still in traffic, you can restart the engine and get
another 25–30 seconds of operation. Do this only if you
have to, since there is a problem that can harm the
engine if it isn’t fixed. Engine automatic shutdown, for
gasoline engines, requires activation by your dealer.
High Idle System (Caterpillar®
Diesel and Gasoline Engines)
Your vehicle has both automatic and manual high idle
capabilities.
2-16
When the engine is started, it will slowly ramp up to the
high idle speed after a delay of a few seconds up to
about two minutes. For this method to work properly
there must be no throttle or brake pedal faults, and the
throttle pedal must not fall below 75 percent of wide
open throttle while pressing the brake pedal.
The engine idle speed will return to normal once the
following conditions are met:
•Once engine coolant temperature reaches
150°F (65°C).
•Air intake temperature reaches 41°F (5°C).
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 inputs are removed, the engine idle speed
will slowly ramp back up 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’ve started your engine, let it run for
20 to 30 seconds before you put a load on the engine.
Butdon’tleave 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 doesn’t begin to rise within
15 seconds of starting, stop the engine and find the
cause.
•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.
2-22
Instrument Panel Overview...............................3-4
Hazard Warning Flashers................................3-5
Other Warning Devices...................................3-6
Horn.............................................................3-6
Tilt Wheel.....................................................3-7
Turn Signal/Multifunction Lever.........................3-7
Exterior Lamps.............................................3-13
Interior Lamps..............................................3-15
Instrument Panel Switchbank..........................3-16
Accessory Power Outlets...............................3-17
Ashtrays and Cigarette Lighter........................3-18
Climate Controls............................................3-19
Climate Control System.................................3-19
Outlet Adjustment.........................................3-22
Rear Heating System....................................3-23
Warning Lights, Gages, and Indicators............3-23
Instrument Panel Cluster................................3-24
Speedometer and Odometer...........................3-25
Tachometer.................................................3-26
Safety Belt Reminder Light.............................3-26
Safety Belt Reminder Tone............................3-26
Air Bag Readiness Light................................3-27
Air Bag Off Light..........................................3-28Charging System Light..................................3-30
Voltmeter Gage............................................3-30
Service Transmission Warning Light................3-31
Range Inhibit Warning Indicator......................3-31
Brake System Warning Light..........................3-31
Parking Brake Warning Light..........................3-34
Anti-Lock Brake System Warning Light.............3-34
Trailer Anti-Lock Brake System
Warning Light...........................................3-35
Engine Coolant Temperature Gage..................3-35
Low Coolant Warning Light............................3-36
Wait to Start Indicator...................................3-36
Malfunction Indicator Lamp.............................3-37
Oil Pressure Gage........................................3-37
Low Oil Level Light.......................................3-38
Change Engine Oil Light................................3-39
Engine Overspeed Warning Light....................3-39
Engine Shutdown Warning Light.....................3-39
Transmission Temperature Gage.....................3-40
Exhaust Brake Indicator Light.........................3-40
Differential Lock Indicator Light.......................3-40
Reduced Engine Power Light.........................3-41
Daytime Running Lamps Indicator Light...........3-41
Section 3 Instrument Panel
3-1
Transmission Temperature Gage
If you have an automatic
transmission, this gage is
located above the
switchbank in the center of
the instrument panel.
When your ignition is on, the gage shows the
temperature of the transmission oil. A reading in the
warning zone, the red area beginning at 300°F (150°C),
means you must stop driving and check into the
cause. One possible cause is a low oil level in the
transmission.
Notice:If you drive your vehicle with the
transmission temperature gage above normal
operating range, you can damage the transmission.
This could lead to costly repairs that would not
be covered by your warranty. Do not drive your
vehicle while the transmission temperature gage
reading is above normal. See your dealer for service.
Exhaust Brake Indicator Light
If your vehicle is equipped
with an exhaust brake, you
will have this light,
located above the comfort
controls in the center of
the instrument panel.
The exhaust brake indicator light will come on and stay
on whenever the diesel engine exhaust brake or
exhaust restrictor is active. For more information, see
Diesel Engine Exhaust Brake on page 2-25.
Differential Lock Indicator Light
If your vehicle has this
feature, this light is located
in the center of the
instrument panel. The light
is on when the inter-axle
differential lock system
is in use.
The light will come on momentarily during starting. If the
light fails to come on, have it repaired as soon as
possible so you will be aware when the lock system is
in use.
3-40
Service............................................................5-3
Doing Your Own Service Work.........................5-4
Two Safety Cautions about Engine Fan
Breakage...................................................5-5
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
Additives.......................................................5-7
Diesel Engine Fuel.........................................5-8
What Fuel to Use...........................................5-8
Very Cold Weather Operation.........................5-10
Water in Fuel...............................................5-10
Running Out of Fuel.....................................5-15
Fuel Filter Replacement.................................5-15
Fuels in Foreign Countries.............................5-16
Filling Your Tank..........................................5-17
Filling a Portable Fuel Container.....................5-18
Checking Things Under the Hood....................5-18
Hood Latches...............................................5-19
Engine Oil (Caterpillar
®Diesel Engine).............5-20
Engine Oil (Gasoline Engine)..........................5-20
Engine Oil (DURAMAX™ Diesel).....................5-25
Engine Air Cleaner/Filter................................5-30
Automatic Transmission Fluid.........................5-31
Manual Transmission Fluid.............................5-32Engine Coolant (Gas and
DURAMAX™ engines)................................5-32
Engine Coolant (Caterpillar
®Diesel Engines).....5-35
Coolant Surge Tank Pressure Cap..................5-35
Engine Overheating.......................................5-36
Cooling System............................................5-38
Engine Fan Noise.........................................5-43
Power Steering Fluid.....................................5-43
Windshield Washer Fluid................................5-44
Brakes........................................................5-46
Battery........................................................5-55
Jump Starting...............................................5-56
Rear Axle.......................................................5-61
Rear Axle Shift Motor....................................5-61
Noise Control System.....................................5-62
Tampering with Noise Control System
Prohibited.................................................5-62
Bulb Replacement..........................................5-63
Replacement Bulbs.......................................5-63
Windshield Wiper Blade Replacement..............5-63
Other Service Items........................................5-64
Fuel Filter....................................................5-64
Primary Fuel Filter and Water Separator..........5-65
Secondary Fuel Filter and Water
Separator/Heater.......................................5-66
Section 5 Service and Appearance Care
5-1
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 your
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
your engine and emission controls.
Aftermarket diesel fuel additives are not tested
by General Motors. Some additives, particularly
those which contain alcohol or water
emulsi ers, may damage your fuel system. If
you believe that unique circumstances call for a
fuel additive to be used, consult your dealer
for advice.
If you ever run out of diesel fuel, it can be
difficult to restart your engine. To avoid all this,
never let your tank get empty.
If you run out of fuel,Running Out of Fuel on page 5-15,
tells you how to restart your engine.
What Fuel to Use
In the United States, for best results use Number 2–D
diesel fuel year-round (above and below freezing
conditions) as oil companies blend Number 2–D fuel to
address climate differences. Number 1–D diesel fuel
may 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 Number
1–D diesel fuel in warm or hot climates. It may result
in stalling, poor starting when the engine is hot and may
damage the fuel injection system.
At a minimum, the diesel fuel you use should meet
specifications ASTM D975-02 (Grade Low Sulfur) 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.
It is acceptable to use diesel fuel containing up to
5% biodiesel (B5), but the final blended fuel must meet
the same specification, ASTM D975–02 (Grade Low
Sulfur), as other fuels used in your vehicle, and
the biodiesel used for making this fuel must meet the
ASTM D6751–02 specification.
5-8