2004 PONTIAC GTO check engine light

Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster if you do a lot of heavy braking. If you keep pace
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 are driving, brake
normally but do not 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 (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, and you may even notice that your
brake pedal moves a little. 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 3-28.
4-6

Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airflow around it. This may cause wind
noise and affect windshield washer performance. Check
with your dealer before adding equipment to the
outside of your vehicle.
Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
Gasoline Octane
Use premium unleaded gasoline with a posted octane of
91 or higher for best performance. You may also use
middle grade or regular unleaded gasoline rated at
87 octane or higher, but your vehicle’s acceleration may
be slightly reduced. If the octane is less than 87, you
may get a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher
as soon as possible. Otherwise, you might damage your
engine.
Gasoline Specications
It is recommended that gasoline meet specifications
which were developed by automobile manufacturers
around the world and contained in the World-Wide Fuel
Charter which is available from the Alliance of
Automobile Manufacturers at www.autoalliance.org.
Gasoline meeting these specifications could provide
improved driveability and emission control system
performance compared to other gasoline.
In Canada, look for the
“Auto Makers’ Choice”
label on the pump.
Canada Only
5-5

A. Engine Compartment Fuse Block. See “Engine
Compartment Fuse Block” underFuses and Circuit
Breakers on page 5-87.
B. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-37.
C. Battery. SeeBattery on page 5-41.
D. Engine Oil Dipstick. SeeEngine Oil on page 5-13.
E. Engine Oil Fill Cap. SeeEngine Oil on page 5-13.
F. Automatic Transmission Dipstick (If Equipped).
SeeAutomatic Transmission Fluid on page 5-19.
G. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-36.
H. Brake Fluid Reservoir. SeeBrakes on page 5-38.
I. Hydraulic Clutch Fluid Reservoir (If Equipped). See
Hydraulic Clutch on page 5-24.
J. Engine Coolant Reservoir. SeeEngine Coolant on
page 5-25.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18.Engine Oil
If the Check Oil message appears on the trip computer
display, it means you need to check your engine oil
level right away.
For more information, seeOil Pressure Light on
page 3-32.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It is a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don’t, the oil
dipstick might not show the actual level.
Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
5-13

Engine Air Cleaner/Filter
SeeEngine Compartment Overview on page 5-12for
more information on location.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at every oil change and
replace at the first oil change after 25,000 miles
(40 000 km).
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter, remove the filter from
the vehicle and lightly shake filter to release loose dust
and dirt. If the filter remains caked with dirt, a new
filter is required.To inspect or replace the engine air cleaner/filter, do the
following:
1. Remove the screws that hold the cover on.
2. Lift off the cover.
3. Check or replace the engine air cleaner/filter.
4. Put the cover back on tightly.
5-18

Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, the fluid in your manual transmission
doesn’t require changing.
How to Check
Because this operation can be difficult, you may choose
to have this done at your dealership service department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading.
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
part or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission uid.Check the fluid level only when your engine is off, the
vehicle is parked on a level place and the transmission
is cool enough for you to rest your fingers on the
transmission case.
Then, follow these steps:
1. Remove the reverse light switch.
2. Check that the lubricant level is up to the bottom of
the switch hole.
3. If the fluid level is good, install the switch and be
sure it is fully seated. If the fluid level is low, add
more fluid as described in the next steps.
How to Add Fluid
Here’s how to add fluid. Refer to the Maintenance
Schedule to determine what kind of fluid to use. See
Recommended Fluids and Lubricants on page 6-13.
1. Remove the reverse light switch.
2. Add fluid at the switch hole. Add only enough
fluid to bring the fluid level up to the bottom of
the switch hole.
3. Install the reverse light switch. Be sure the switch is
fully seated.
5-23

Checking Coolant
The coolant surge tank is located in the engine
compartment on the driver’s side of the vehicle. See
Engine Compartment Overview on page 5-12for more
information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The coolant level should be checked at least weekly, by
looking at the level on the coolant reservoir when the
engine is cold. The vehicle must be on a level surface.
When your engine is cold, the coolant level should
be at or slightly above the COLD FILL mark, at
the center weld joint. The level rises when the engine is
running and drops when the engine cools down. If
the level falls below the weld joint, the coolant should
be added to a little over the mark. Do not overfill,
as coolant requires space to expand when warmed up.
If the Low Coolant message on the trip computer
display comes on and stays on, it means you’re low on
engine coolant. You should check the level as soon
as possible. You may have to check the coolant level
when it is hot. SeeEngine Overheating on page 5-28.
5-27

Brakes
Brake Fluid
Your brake master cylinder
reservoir is filled with
DOT-4 brake fluid. See
Engine Compartment
Overview on page 5-12for
the location of the
reservoir.
There are only two reasons why the brake fluid level in
the reservoir might go down. The first is that the
brake fluid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the fluid level goes back up. The other reason is
that fluid is leaking out of the brake system. If it is, you
should have your brake system fixed, since a leak
means that sooner or later your brakes will not work
well, or will not work at all.So, it is not a good idea to “top off” your brake fluid.
Adding brake fluid will not correct a leak. If you add fluid
when your linings are worn, then you will have too
much fluid when you get new brake linings. You should
add (or remove) brake fluid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can spill on
the engine. The uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
uid only when work is done on the brake
hydraulic system. See “Checking Brake Fluid”
in this section.
When your brake fluid falls
to a low level, your brake
warning light will come
on. SeeBrake System
Warning Light on
page 3-27.
5-38

Electrical System
Add-On Electrical Equipment
Notice:Don’t add anything electrical to your
vehicle unless you check with your dealer rst.
Some electrical equipment can damage your vehicle
and the damage wouldn’t be covered by your
warranty. Some add-on electrical equipment can
keep other components from working as they
should.
Your vehicle has an air bag system. Before attempting
to add anything electrical to your vehicle, see
Servicing Your Air Bag-Equipped Vehicle on page 1-52.
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by fuses, circuit breakers and thermal links
in the wiring itself. This greatly reduces the chance of
fires caused by electrical problems.
Look at the metallic band inside the fuse. If the band is
broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the correct size.
If you ever have a problem on the road and don’t have a
spare fuse, you can borrow one. Just pick some
feature of your vehicle that you can get along
without — like the radio or cigarette lighter — and use
its fuse, if it is the size you need. Replace it as soon as
you can.
Before replacing a fuse, turn every vehicle electrical
switch off.
There are two fuse blocks in your vehicle: the
instrument panel fuse block and the engine compartment
fuse block.
5-87