Reduced Engine Power Light
If the check engine and
reduced engine power
lights are on, the throttle
may be disabled, and
a noticeable reduction in
the vehicle’s performance
may occur.
If the reduced engine power light is on, but there is no
reduction in performance, proceed to your destination.
The performance may be reduced the next time
the vehicle is driven. The vehicle may be driven at a
reduced speed while the reduced engine power light is
on, but acceleration and speed may be reduced.
Anytime the check engine light stays on, the vehicle
should be taken to an authorized GM dealer as soon as
possible for service.
Daytime Running Lamps
Indicator Light
This light is located on the
instrument panel cluster. It
goes on whenever the
Daytime Running Lamps
are on.
SeeDaytime Running LampsunderExterior Lamps on
page 3-13for further information.
When it begins to get dark, the DRL indicator light is a
reminder to turn on your headlamps.
3-41
Low Washer Fluid Warning Light
This light will come on
when your vehicle is low
on windshield washer fluid.
For more information, seeWindshield Washer Fluid on
page 5-44.
Check Gages Warning Light
This light will come on as
you’re starting the engine,
just as a check.
If this light comes on and stays on while you are driving.
it means that either your engine coolant temperature
gage or your engine oil pressure gage may be showing
a reading in the warning zone.When the check gages light comes on, you will also
hear a warning tone. The tone and the light will
stay activated until the problem is corrected.
This light may also come on if your vehicle is equipped
with the optional automatic engine shutdown system
and engine shutdown has begun. SeeEngine Alarm and
Automatic ShutdownunderStarting Your Diesel
Engine on page 2-14.
Fuel Gage
Your fuel gage is located
on the right side of your
instrument panel cluster.
When the ignition is on, your fuel gage lets you know
about how much fuel you have left. When the gage first
shows empty, you’ll still have a little fuel left, but you
should get more fuel soon.
3-42
Hourmeter Gage
The instrument panel cluster displays the accumulated
engine run time hours using the reconfigurable
odometer VF display. The engine run time hours
displays only when the ignition is in the OFF or ACC
position and the trip reset switch is pressed for
about four seconds.
When the ignition is in the OFF or ACC position, the
instrument panel cluster displays the engine
accumulated hours for up to 30 seconds. The value of
the accumulated hours does not change when the
battery is disconnected.
The hourmeter resets to 0.0 when 10,000 hours are
accumulated. The instrument panel cluster begins
to reaccumulate the engine run time hours from 0.0
hours.
Audio System(s)
Notice:Before you add any sound equipment to
your vehicle – like a tape player, CB radio, mobile
telephone or two-way radio – be sure you can
add what you want. If you can, it’s very important to
do it properly. Added sound equipment may
interfere with the operation of your vehicle’s engine,
radio or other systems, and even damage them.Your vehicle’s systems may interfere with the
operation of sound equipment that has been added
improperly.
So, before adding sound equipment, check with
your dealer and be sure to check federal rules
covering mobile radio and telephone units.
Your audio system has been designed to operate easily
and to give years of listening pleasure. You will get
the most enjoyment out of it if you acquaint yourself with
it first. Figure out which radio you have in your vehicle,
find out what your audio system can do, and how to
operate all of its controls to be sure you are getting
the most out of the advanced engineering that went
into it.
Setting the Time
Press and hold the HR or MIN arrow for two seconds.
Then press the HR (down) arrow until the correct
hour appears on the display. Press and hold the
MIN (up) arrow until the correct minute appears on
the display. The time may be set with the ignition on
or off.
3-45
Anti-lock Brake System (ABS)
Your vehicle has anti-lock brakes. ABS is an advanced
electronic braking system that will help prevent a
braking skid.
When you start your engine and begin to drive away,
your anti-lock brake system will check itself. You
may hear a momentary motor or clicking noise while
this test is going on. This is normal.
If there is a problem with
the anti-lock brake system,
this warning light will
stay on. SeeAnti-Lock
Brake System Warning
Light on page 3-34.
Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down. If
one of the wheels is about to stop rolling, the computer
will separately work the brakes at each wheel.
4-7
Highway Hypnosis
Is there actually such a condition as “highway
hypnosis”? Or is it just plain falling asleep at the wheel?
Call it highway hypnosis, lack of awareness, or
whatever.
When you drive the vehicle for a long distance, there is
something about an easy stretch of road with the
same scenery, along with the hum of the tires on the
road, the drone of the engine, and the rush of the wind
against the vehicle that can make you sleepy. Do
not let it happen to you! If it does, your vehicle can leave
the road inless than a second,and you could crash
and be injured.
What can you do about highway hypnosis? First, be
aware that it can happen.
Then here are some tips:
•Make sure your vehicle is well ventilated, with a
comfortably cool interior.
•Keep your eyes moving. Scan the road ahead and
to the sides. Check your mirrors and your
instruments frequently.
•If you get sleepy, pull off the road into a rest,
service or parking area and take a nap, get some
exercise, or both. For safety, treat drowsiness
on the highway as an emergency.
Hill and Mountain Roads
Driving on steep hills or mountains is different from
driving in flat or rolling terrain.
4-23
Here are some tips that can make your drive through
steep country safer:
•Keep the vehicle in good shape. Check all fluid
levels and also the brakes, tires, cooling system
and transmission. These parts can work hard
on mountain roads.
•Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift to a lower gear when you go
down a steep or long hill.
{CAUTION:
If you do not shift down, your brakes could get
so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Shift down
to let your engine assist your brakes on a
steep downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. Your brakes will have
to do all the work of slowing down. They could
get so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Always
have your engine running and your vehicle in
gear when you go downhill.
•Know how to go uphill. Use lower gears. They help
cool your engine and transmission, and you can
climb the hill better.
•Stay in your own lane when driving on two-lane
roads in hills or mountains. Do not swing wide
or cut across the center of the road. Drive at speeds
that let you stay in your own lane.
•As you go over the top of a hill, be alert. There
could be something in your lane, like a stalled car or
an accident.
•You may se highway signs on mountains that warn
of special problems. Examples are long grades,
passing or no-passing zones, a falling rocks area,
winding roads and special truck lanes. Be alert
to these and take appropriate action.
4-24
•Put on extra clothing or wrap a blanket around you.
If you have no blankets or extra clothing, make
body insulators from newspapers, burlap bags, rags,
floor mats — anything you can wrap around
yourself or tuck under your clothing to keep warm.
You can run the engine to keep warm, but be careful.
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You can not see it
or smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle if any is blocking your
exhaust pipe. And check around again from
time to time to be sure snow does not
collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get and
it keeps the battery (or batteries) charged. You will
need a well-charged battery (or batteries) to restart the
vehicle, and possibly for signaling later on with your
headlamps. Let the heater run for a while.
4-28
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