2009 GMC YUKON HYBRID engine

Power Steering Fluid
The vehicle has electric power steering and does not
use power steering fluid.
Brakes
Brake Fluid
The brake master cylinder
reservoir is filled with
DOT-3 brake fluid. See
Engine Compartment
Overview on page 5-4
for the location of
the reservoir.
There are only two reasons why the brake fluid level in
the reservoir might go down:
•The brake fluid level goes down because of normal
brake lining wear. When new linings are installed,
the fluid level goes back up.
•A fluid leak in the brake hydraulic system can also
cause a low fluid level. Have the brake hydraulic
system fixed, since a leak means that sooner
or later the brakes will not work well.Do not top off the brake fluid. Adding fluid does not
correct a leak. If fluid is added when the linings
are worn, there will be too much fluid when new brake
linings are installed. Add or remove brake fluid, as
necessary, only when work is done on the brake
hydraulic system.
{CAUTION:
If too much brake fluid is added, it can spill on
the engine and burn, if the engine is hot enough.
You or others could be burned, and the vehicle
could be damaged. Add brake fluid only when
work is done on the brake hydraulic system.
See “Checking Brake Fluid” in this section.
When the brake fluid falls to a low level, the brake
warning light comes on. See “Brake System Warning
Light” in the owner manual.
Refer to the Maintenance Schedule to determine when
to check the brake fluid. See “Scheduled Maintenance”
in the owner manual.
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Checking Brake Fluid
Check brake fluid by looking at the brake fluid reservoir.
SeeEngine Compartment Overview on page 5-4.
With the engine not running for at least one minute, the
maximum fluid level (A) is at the top of the reservoir
body. With the engine running, the fluid level should be
in the proper operating range (B) between the MIN
and MAX marks. If it is not, have the brake hydraulic
system checked to see if there is a leak.After work is done on the brake hydraulic system,
make sure the level, with the engine running, is in
the proper operating range (B) between the MIN and
MAX marks.
What to Add
Use only new DOT-3 brake fluid from a sealed
container. See “Recommended Fluids and Lubricants”
in the owner manual.
Always clean the brake fluid reservoir cap and the area
around the cap before removing it. This helps keep
dirt from entering the reservoir.
{CAUTION:
With the wrong kind of fluid in the brake hydraulic
system, the brakes might not work well. This could
cause a crash. Always use the proper brake fluid.
5-12

Notice:
Using the wrong uid can badly damage brake
hydraulic system parts. For example, just a
few drops of mineral-based oil, such as engine
oil, in the brake hydraulic system can damage
brake hydraulic system parts so badly that they
will have to be replaced. Do not let someone
put in the wrong kind of uid.
If brake uid is spilled on the vehicle’s painted
surfaces, the paint nish can be damaged.
Be careful not to spill brake uid on the
vehicle. If you do, wash it off immediately.
See “Washing Your Vehicle” in the owner
manual.
Brake Wear
This vehicle has disc brakes. Disc brake pads have
built-in wear indicators that make a high-pitched warning
sound when the brake pads are worn and new pads
are needed. The sound can come and go or be heard all
the time the vehicle is moving, except when applying
the brake pedal firmly.
{CAUTION:
The brake wear warning sound means that soon
the brakes will not work well. That could lead to an
accident. When the brake wear warning sound is
heard, have the vehicle serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates can cause a brake
squeal when the brakes are first applied or lightly
applied. This does not mean something is wrong with
the brakes.
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Notice:If you leave the radio or other accessories
on during the jump starting procedure, they
could be damaged. The repairs would not be
covered by the warranty. Always turn off the radio
and other accessories when jump starting the
vehicle.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or the accessory power outlets. Turn off
the radio and all the lamps that are not needed.
This avoids sparks and helps save both batteries.
It could save the radio!
4. Open the hood on the other vehicle and locate the
positive (+) and negative (−) terminal locations on
that vehicle.
Your vehicle has a remote positive (+) and a remote
negative (−) jump starting terminal. You should
always use these remote terminals instead of the
terminals on the battery.If the vehicle has a remote positive (+), it is located
under a red plastic cover at the positive battery
post. To uncover the remote positive (+) terminal,
open the red plastic cover.
5. The remote negative (−) is a solid engine ground.
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{CAUTION:
An electric fan can start up even when the engine
is not running and can injure you. Keep hands,
clothing and tools away from any underhood
electric fan.
{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight if
you need more light.
CAUTION: (Continued)
CAUTION: (Continued)
Be sure the battery has enough water. You do not
need to add water to the battery installed in your
new vehicle. But if a battery has filler caps, be
sure the right amount of fluid is there. If it is low,
add water to take care of that first. If you do not,
explosive gas could be present.
Battery fluid contains acid that can burn you.
Do not get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
{CAUTION:
Fans or other moving engine parts can injure you
badly. Keep your hands away from moving parts
once the engine is running.
5-18

6. Check that the jumper cables do not have loose
or missing insulation. If they do, you could get a
shock. The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) goes to
positive (+) or to a remote positive (+) terminal
if the vehicle has one. Negative (−) will go to
a heavy, unpainted metal engine part or a solid
engine ground.
Do not connect positive (+) to negative (−)oryou
will get a short that would damage the battery
and maybe other parts too. Do not connect
the negative (−) cable to the negative (−) terminal
on the dead battery because this can cause sparks.
7. Connect the red positive (+) cable to the positive (+)
terminal of the vehicle with the dead battery.
Use a remote positive (+) if the vehicle has one.8. Do not let the other end touch metal. Connect it
to the positive (+) terminal of the good battery.
Use a remote positive (+) if the vehicle has one.
9. Now connect the black negative (−) cable to the
negative (−) terminal of the good battery. Use a
remote negative (−) if the vehicle has one.
Do not let the other end touch anything until the
next step. The other end of the negative (−) cable
does not go to the dead battery. It goes to a
heavy, unpainted metal engine part or to the remote
negative (−) terminal on the vehicle with the dead
battery.
10. Connect the other end of the negative (−) cable to
the remote negative (−) terminal, on the vehicle
with the dead battery.
11. Now start the vehicle with the good battery and run
the engine for a while.
12. Try to start the vehicle that had the dead battery.
If it will not start after a few tries, it probably needs
service.
5-19

Notice:If the jumper cables are connected or
removed in the wrong order, electrical shorting may
occur and damage the vehicle. The repairs would
not be covered by your warranty. Always connect
and remove the jumper cables in the correct
order, making sure that the cables do not touch
each other or other metal.
Jumper Cable Removal
A. Heavy, Unpainted Metal Engine Part or Remote
Negative (−) Terminal
B. Good Battery or Remote Positive (+) and Remote
Negative (−) Terminals
C. Dead Battery or Remote Positive (+) TerminalTo disconnect the jumper cables from both vehicles:
1. Disconnect the black negative (−) cable from
the vehicle that had the bad battery.
2. Disconnect the black negative (−) cable from the
vehicle with the good battery.
3. Disconnect the red positive (+) cable from the
vehicle with the good battery.
4. Disconnect the red positive (+) cable from the other
vehicle.
5. Return the remote positive (+) terminal cover to
its original position.
5-20

Replacement Bulbs
Exterior Lamp Bulb Number
Back-up Lamp and Rear Turn
Signal Lamp3156
Sidemarker Lamp 194
For replacement bulbs not listed here, contact your
dealer/retailer.
Electrical System
Fuses and Circuit Breakers
The wiring circuits in the vehicle are protected from
short circuits by a combination of fuses, circuit breakers
and fusible thermal links. This greatly reduces the
chance of fires caused by electrical problems.
Be sure you replace a bad fuse with a new one of the
identical size and rating.If you ever have a problem on the road and do not have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of the vehicle that you
can get along without, like the radio or cigarette
lighter, and use its fuse, if it is the correct amperage.
Replace it as soon as you can.
The vehicle also has a special fuse in the battery box
for the 300-volt batteries. If this fuse has failed and
needs to be replaced, the vehicle will be disabled and
you will need to have the vehicle repaired by your
dealer/retailer. Do not attempt to self-service this fuse.
Underhood Fuse Block
Hybrid Auxiliary Underhood Fuse
Block
The hybrid underhood fuse block is located in the
engine compartment near the front of the vehicle.
Lift the cover for access to the fuse/relay block.
SeeEngine Compartment Overview on page 5-4for
more information on its location. For more information on
the main underhood fuse block, see “Underhood Fuse
Block” in the owner manual.
5-22