check engine GMC YUKON 2003 User Guide

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
itfirst. 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’re getting the
most out of the advanced engineering that went into it.Your vehicle may have a feature called Retained
Accessory Power (RAP). With RAP, you can play your
audio system even after the ignition is turned off.
See“Retained Accessory Power (RAP)”underIgnition
Positions on page 2-19.
Setting the Time for Radios without
Radio Data Systems (RDS)
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.
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with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking.
That means better braking and longer brake life.
If your engine ever stops while you’re driving, brake
normally but don’t pump your brakes. If you do,
the pedal may get harder to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and
the brake pedal will be harder to push.
Anti-lock Brake System
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’s a problem with
the anti-lock brake system,
this warning light will
stay on. SeeAnti-Lock
Brake System Warning
Light on page 3-44.
Along with ABS, your vehicle has a Dynamic Rear
Proportioning (DRP) system. If there’s a DRP problem,
both the brake and ABS warning lights will come on
accompanied by a 10-second chime. The lights
and chime will come on each time the ignition is turned
on until the problem is repaired. See your dealer for
service.
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Remember: Anti-lock doesn’t change the time you need
to get your foot up to the brake pedal or always
decrease stopping distance. If you get too close to the
vehicle in front of you, you won’t have time to apply
your brakes if that vehicle suddenly slows or stops.
Always leave enough room up ahead to stop, even
though you have anti-lock brakes.
Using Anti-Lock
Don’t pump the brakes. Just hold the brake pedal down
rmly and let anti-lock work for you. You may feel
the brakes vibrate, or you may notice some noise, but
this is normal.
Braking in Emergencies
With anti-lock, you can steer and brake at the same
time. In many emergencies, steering can help you more
than even the very best braking.
Supplemental Brake Assist System
If your vehicle has vacuum assist power brakes, it is also
equipped with a supplemental brake assist system
that supplies additional vacuum to the vacuum brake
booster if engine vacuum is reduced. Under certain
conditions, the supplemental brake assist system may
run briey after starting your vehicle or when you
apply and release the brake pedal and it may continueto run even after you have removed your foot from the
brake pedal. When the supplemental brake assist
system is operating, you may hear a motor running or
feel a slight vibration in the steering wheel or brake
pedal. This indicates that the supplemental brake assist
system is working to supply additional vacuum for
your vacuum assist power brakes. This is a normal
operation of your brake system and does not require that
the brake system be serviced.
Each time you start your vehicle and accelerate to
10 mph, the supplemental brake assist system
will perform a self-diagnostic check of the system and
you may hear or feel the supplemental brake assist
motor run briey. While you are driving your vehicle, the
supplemental brake assist system monitors itself to
ensure that it is operating properly. If there is a problem
with the supplemental brake assist system, the
SERVICE BRAKE BOOSTER message will be displayed
on the Driver Information Center. SeeDIC Warnings
and Messages on page 3-64.
If your supplemental brake assist system runs every
time you apply and release the brake pedal or you notice
that the brake pedal has suddenly become much
harder to push and the vehicle takes longer to stop, you
should have your vehicle serviced as soon as possible.
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Reduce your speed according to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you may tend to think you are
going slower than you actually are.
Before Leaving on a Long Trip
Make sure you’re ready. Try to be well rested. If you
must start when you’re not fresh—such as after a day’s
work—don’t plan to make too many miles thatrst
part of the journey. Wear comfortable clothing and shoes
you can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it’s ready to go. If it needs
service, have it done before starting out. Of course,
you’llnd experienced and able service experts in GM
dealerships all across North America. They’ll be
ready and willing to help if you need it.
Here are some things you can check before a trip:
Windshield Washer Fluid:Is the reservoir full? Are
all windows clean inside and outside?
Wiper Blades:Are they in good shape?
Fuel, Engine Oil, Other Fluids:Have you checked
all levels?
Lamps:Are they all working? Are the lenses clean?
Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough for
long-distance driving? Are the tires all inated to the
recommended pressure?
Weather Forecasts:What’s the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
Maps:Do you have up-to-date maps?
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.
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. Don’t
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.
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If you drive regularly in steep country, or if you’re
planning to visit there, here are some tips that can make
your trips safer and more enjoyable. SeeOff-Road
Driving with Your Four-Wheel-Drive Vehicle on
page 4-22for information about driving off-road.
Keep your vehicle in good shape. Check alluid
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 don’t shift down, your brakes could get
so hot that they wouldn’t 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 wouldn’t 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. You may want to shift down
to a lower gear. The lower gears 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. Don’t swing wide or
cut across the center of the road. Drive at speeds
that let you stay in your own lane.
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{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’t 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, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow
doesn’t collect there.
Open a window just a little on the side of the
vehicle that’s 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 charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine off and close the window almost
all the way to preserve the heat. Start the engine
again and repeat this only when you feel really
uncomfortable from the cold. But do it as little as
possible. Preserve the fuel as long as you can. To help
keep warm, you can get out of the vehicle and do
some fairly vigorous exercises every half hour or so until
help comes.
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Trailer Brakes
If your trailer weighs more than 2,000 lbs. (900 kg)
loaded, then it needs its own brakes–and they must be
adequate. Be sure to read and follow the instructions
for the trailer brakes so you’ll be able to install,
adjust and maintain them properly.
If your vehicle is equipped with Stabilitrak
®, your trailer
cannot tap into the vehicle’s hydraulic brake system.
Your trailer brake system can tap into the vehicle’s
hydraulic brake system only if:
The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.
The trailer’s brake system will use less than
0.02 cubic inches (0.3 cc) ofuid from your vehicle’s
master cylinder. Otherwise, both braking systems
won’t work well. You could even lose your brakes.
If everything checks out this far, make the brake tap at
the port on the master cylinder that sends theuid
to the rear brakes. But don’t use copper tubing for this.
If you do, it will bend andnally break off. Use steel
brake tubing.
Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon
monoxide (CO) could come into your vehicle.
You can’t see or smell CO. It can cause
unconsciousness or death. See“Engine
Exhaust”in the Index. To maximize your safety
when towing a trailer:
•Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
•Keep the rear-most windows closed.
•If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use
the climate control setting for maximum air
because it only recirculates the air inside
your vehicle. See“Climate Controls”in the
Index.
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Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns
than normal. Do this so your trailer won’t strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel willash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will alsoash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel willash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or, if necessary, a lower
gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See“Tow/Haul Mode”
for more information.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine off. If you do get
the overheat warning, seeEngine Overheating on
page 5-29.
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When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmissionuid (don’t overll),
engine oil, axle lubricant, belts, cooling system and brake
system. Each of these is covered in this manual, and the
Index will help yound them quickly. If you’re trailering,
it’s a good idea to review these sections before you start
your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Your vehicle is equipped with the following wiring
harnesses for towing a trailer.
Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector,
is located at the rear of the vehicle and is tied to
the vehicle’s frame. The harness connector can be
plugged into a seven-pin universal heavy-duty trailer
connector available through your dealer.
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Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specifications....................................5-4
California Fuel...............................................5-5
Additives.......................................................5-5
Fuel E-85 (85% Ethanol).................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.....................5-10
Checking Things Under
the Hood....................................................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-23
Engine Coolant.............................................5-26
Coolant Surge Tank Pressure Cap..................5-29Engine Overheating.......................................5-29
Cooling System............................................5-32
Engine Fan Noise.........................................5-37
Power Steering Fluid.....................................5-38
Windshield Washer Fluid................................5-39
Brakes........................................................5-40
Battery........................................................5-43
Jump Starting...............................................5-44
All-Wheel Drive..............................................5-49
Rear Axle.......................................................5-50
Four-Wheel Drive............................................5-51
Front Axle......................................................5-52
Bulb Replacement..........................................5-52
Halogen Bulbs..............................................5-53
Headlamps..................................................5-53
Front Turn Signal, Sidemarker and Daytime
Running Lamps.........................................5-54
Side Identification Marker Lamps.....................5-55
Roof Marker Lamps......................................5-55
Taillamps.....................................................5-57
Replacement Bulbs
.......................................5-59
Section 5 Service and Appearance Care
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