check engine GMC SIERRA 2007 Owner's Guide

5. Inspect or replace the engine air cleaner/lter.
6. Reinstall the cover and tighten the screws.
7. Reset the air lter restriction indicator, if
the vehicle has one, by pressing the top button
on the indicator.
{CAUTION:
Operating the engine with the air
cleaner/lter off can cause you or others
to be burned. The air cleaner not only
cleans the air; it helps to stop ames if
the engine backres. If it is not there and
the engine backres, you could be
burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/lter off.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission uid level. The only reason for uid
loss is a transmission leak or overheating the
transmission. If you suspect a small leak, then use
the following checking procedures to check the
uid level. However, if there is a large leak, then it
may be necessary to have the vehicle towed to
a dealership service department and have it
repaired before driving the vehicle further.
Notice:Use of the incorrect automatic
transmission uid may damage your vehicle,
and the damages may not be covered by
your warranty. Always use the automatic
transmission uid listed inRecommended
Fluids and Lubricants on page 635.
Change the uid and lter at the intervals listed in
the Maintenance Schedule. SeeScheduled
Maintenance (Gasoline Engine) on page 623.Be
sure to use the transmission uid listed in
Recommended Fluids and Lubricants on page 635.
508

How to Check Automatic Transmission
Fluid
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 parts 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.
Before checking the uid level, prepare your
vehicle as follows:
1. Start the engine and park your vehicle on a
level surface. Keep the engine running.
2. Apply the parking brake and place the shift
lever in PARK (P).3. With your foot on the brake pedal, move the
shift lever through each gear range, pausing
for about three seconds in each range.
Then, move the shift lever back to PARK (P).
4. Allow the engine to idle (500 – 800 rpm) for
at least one minute. Slowly release the brake
pedal.
5. Keep the engine running and press the
Trip/Fuel button or trip odometer reset
stem until TRANS TEMP (Transmission
Temperature) displays on the Driver
Information Center (DIC).
6. Using the TRANS TEMP reading, determine
and perform the appropriate check procedure.
If the TRANS TEMP reading is not within
the required temperature ranges, allow
the vehicle to cool, or operate the vehicle until
the appropriate transmission uid temperature
is reached.
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Cold Check Procedure
Use this procedure only as a reference to
determine if the transmission has enough uid to
be operated safely until a hot check procedure
can be made. The hot check procedure is the most
accurate method to check the uid level. Perform
the hot check procedure at the rst opportunity.
Use this cold check procedure to check uid level
when the transmission temperature is between
80°F and 90°F (27°C and 32°C).
1. Locate the transmission dipstick at the rear of
the engine compartment, on the passenger’s
side of the vehicle.
The dipstick handle has
this graphic. SeeEngine
Compartment Overview
on page 498for
more information.
2. Flip the handle up, and then pull out the
dipstick and wipe it with a clean rag or
paper towel.3. Install the dipstick by pushing it back in all the
way, wait three seconds, and then pull it back
out again.
4. Check both sides of the dipstick, and read the
lower level. Repeat the check procedure to
verify the reading.
5. If the uid level is below the COLD check
band, add only enough uid as necessary
to bring the level into the COLD band. It does
not take much uid, generally less than
one pint (0.5L). Do not overll.
510

6. Perform a hot check at the rst opportunity
after the transmission reaches a normal
operating temperature between 160°F to
200°F (71°C to 93°C).
7. If the uid level is in the acceptable range,
push the dipstick back in all the way, then
ip the handle down to lock the dipstick
in place.
Hot Check Procedure
Use this procedure to check the transmission uid
level when the transmission uid temperature is
between 160°F and 200°F (71°C and 93°C).
The hot check is the most accurate method to
check the uid level. The hot check should be
performed at the rst opportunity in order to verify
the cold check. The uid level rises as uid
temperature increases, so it is important to ensure
the transmission temperature is within range.1. Locate the transmission dipstick at the rear of
the engine compartment, on the passenger’s
side of the vehicle.
The dipstick handle has
this graphic. SeeEngine
Compartment Overview
on page 498for
more information.
2. Flip the handle up, and then pull out the
dipstick and wipe it with a clean rag or
paper towel.
3. Install the dipstick by pushing it back in all the
way, wait three seconds, and then pull it back
out again.
4. Check both sides of the dipstick, and read the
lower level. Repeat the check procedure to
verify the reading.
511

What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant which will
not damage aluminum parts. If you use this coolant
mixture, you do not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant
mixture, your engine could overheat and be
badly damaged. The repair cost would not be
covered by your warranty. Too much water
in the mixture can freeze and crack the engine,
radiator, heater core, and other parts.
If you have to add coolant more than four times a
year, have your dealer check your cooling
system.
Notice:If you use extra inhibitors and/or
additives in your vehicle’s cooling system, you
could damage your vehicle. Use only the
proper mixture of the engine coolant listed in
this manual for the cooling system. See
Recommended Fluids and Lubricants on
page 635for more information.
514

Checking Coolant
The coolant surge tank is located in the engine
compartment on the passenger’s side of the
vehicle. SeeEngine Compartment Overview on
page 498for 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 vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the
FULL COLD mark on the coolant surge tank.
If your vehicle has a low coolant sensor and the
LOW COOLANT LEVEL message comes on
and stays on, it means you are low on engine
coolant. See “LOW COOLANT LEVEL” underDIC
Warnings and Messages on page 279.
Adding Coolant
If you need more coolant, add the proper
DEX-COOL®coolant mixture at the surge tank,
but only when the engine is cool. SeeCooling
System on page 520for more information.
{CAUTION:
You can be burned if you spill coolant on
hot engine parts. Coolant contains
ethylene glycol, and it will burn if the
engine parts are hot enough. Do not spill
coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
515

Cooling System
If your vehicle has the DURAMAX®Diesel engine,
see the DURAMAX®Diesel manual for more
information.
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
{CAUTION:
An electric engine cooling fan can start
even when the engine is not running.
To avoid injury, always keep hands,
clothing, and tools away from any engine
cooling fan.
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
Check the coolant level after the system cools
down. Some amount of coolant may be lost due
to overheating.
5.3L Engine (4.3L, 4.8L and 6.0L Similar)
520

How to Add Coolant to the Coolant
Surge Tank for Gasoline Engines
If your vehicle has a diesel engine, see “Cooling
System” in the DURAMAX®Diesel Supplement for
the proper coolant ll procedure.
If you have not found a problem yet, check to see
if coolant is visible in the surge tank. If coolant
is visible but the coolant level is not at or above the
FULL COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant at
the coolant surge tank, but be sure the cooling
system, including the coolant surge tank pressure
cap, is cool before you do it. SeeEngine
Coolant on page 513for more information.If no coolant is visible in the surge tank, add
coolant as follows:
{CAUTION:
Steam and scalding liquids from a hot
cooling system can blow out and burn
you badly. They are under pressure, and if
you turn the coolant surge tank pressure
cap — even a little — they can come out at
high speed. Never turn the cap when the
cooling system, including the coolant
surge tank pressure cap, is hot. Wait for
the cooling system and coolant surge
tank pressure cap to cool if you ever have
to turn the pressure cap.
522

Power Steering Fluid
SeeEngine
Compartment Overview
on page 498for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power
steering uid unless you suspect there is a leak in
the system or you hear an unusual noise. A
uid loss in this system could indicate a problem.
Have the system inspected and repaired.
How to Check Power Steering Fluid
To check the power steering uid, do the following:
1. Turn the key off and let the engine
compartment cool down.
2. Wipe the cap and the top of the reservoir
clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the
uid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough uid to bring the level
up to the mark.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 635.
Always use the proper uid. Failure to use the
proper uid can cause leaks and damage hoses
and seals.
526

Brakes
Brake Fluid
The brake master
cylinder reservoir is
lled with DOT-3 brake
uid. SeeEngine
Compartment Overview
on page 498for the
location of the reservoir.
There are only two reasons why the brake uid
level in the reservoir might go down. The rst
is that the brake uid goes down to an acceptable
level during normal brake lining wear. When
new linings are put in, the uid level goes back
up. The other reason is that uid is leaking out of
the brake system. If it is, you should have the
brake system xed, since a leak means that
sooner or later the brakes will not work well.So, it is not a good idea to top off the brake uid.
Adding brake uid will not correct a leak. If
you add uid when the linings are worn, then you
will have too much uid when you get new
brake linings. You should add or remove brake
uid, 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.
Refer to the Maintenance Schedule to determine
when to check the brake uid. SeeScheduled
Maintenance (Gasoline Engine) on page 623.
528