2002 CHEVROLET SILVERADO check engine

6-22
3. Remove the air filter by pulling downward on the
element. Remove the second portion of the air filter
by sliding it towards the rear of the vehicle and then
pulling downward.
4. Install the new filter by reversing the steps listed
previously. Be sure to follow any instructions that
may be included in the replacement filter package.
Because this procedure can be a little difficult,
you may choose to have it done at your dealer's
service department.
Refer to the Maintenance Schedule to determine when to
replace the passenger compartment air filter. See
ªScheduled Maintenanceº in the Index.Automatic Transmission Fluid
(Except Allison Transmission)
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 50,000 miles
(83 000 km) if the vehicle's GVWR is over 8,600 or
if the vehicle is mainly driven under one or more of
these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.

In hilly or mountainous terrain.

When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.
If your vehicle's GVWR is not over 8,600 and you do not
use your vehicle under any of these conditions, change
the fluid and filter every 100,000 miles (166 000 km).
See ªScheduled Maintenance Servicesº in the Index.

6-23 How to Check
Because this operation can be a little difficult,
you may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission fluid.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:

When outside temperatures are above 90F (32C).

At high speed for quite a while.

In heavy traffic
-- especially in hot weather.

While pulling a trailer.
To get the right reading, the fluid should be at
normal operating temperature, which is 180F
to 200F (82C to 93C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50F
(10C). If it's colder than 50F (10C), drive the
vehicle in THIRD (3) until the engine temperature gage
moves and then remains steady for 10 minutes.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine run at
idle for five minutes if outside temperatures are 50F
(10C) or more. If it's colder than 50F (10C), you
may have to idle the engine longer. Should the fluid
level be low during this cold check, you must check the
fluid hot before adding fluid. Checking the fluid hot will
give you a more accurate reading of the fluid level.

6-24
Checking the Fluid Level
Prepare your vehicle as follows:

Park your vehicle on a level place. Keep the
engine running.

With the parking brake applied, place the shift lever
in PARK (P).

With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).

Let the engine run at idle for three minutes or more.
Then, without shutting off the engine, follow these steps:
The red transmission dipstick handle labeled
ªTRANS/LOCKº, or labeled with the graphic shown,
is located at the rear of the engine compartment, on the
passenger's side.
See ªEngine Compartment Overviewº in the Index for
further information on location.
1. Flip the handle up and then pull out the dipstick and
wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.

6-26
Automatic Transmission Fluid
(Allison Only)
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 25,000 miles
(41 500 km) if the vehicle is mainly driven under one or
more of these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.

In hilly or mountainous terrain.

When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of
these conditions, change the fluid and filter
every 50,000 miles (83 000 km).
See ªScheduled Maintenance Servicesº in the Index.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission fluid.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:

When outside temperatures are above 90F (32C).

At high speed for quite a while.

In heavy traffic
-- especially in hot weather.

While pulling a trailer.

6-27
Checking the Fluid Level
Prepare your vehicle as follows:

Park your vehicle on a level place. Keep the
engine running.

With the parking brake applied, place the shift lever
in PARK (P).

With your foot on the brake pedal, run the engine for
at least once minute and shift to DRIVE (D). Then
shift to NEUTRAL (N) and then REVERSE (R) to
fill the hydraulic system. Then, position the shift
lever in PARK (P).

Allow the engine to run at idle (500
- 800 rpm).
Slowly release the brake pedal.
Then, without shutting off the engine, follow these steps:Cold Check Procedure
The purpose of the cold check is to determine if the
transmission has enough fluid to be operated safely until
a hot check can be made. The fluid level rises as fluid
temperature increases. DO NOT fill above the COLD
CHECK band if the transmission fluid is below normal
operating temperatures.
1. Pull out the dipstick and wipe it with a clean rag or
paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
3. Check the fluid level reading. Repeat the check
procedure to verify the reading.
4. If the fluid level is within the COLD CHECK band,
the transmission may be operated until the fluid is
hot enough to perform a hot check. If the fluid level
is not within the COLD CHECK band, add or drain
fluid as necessary to bring the level into the middle
of the COLD CHECK band.
5. Perform a hot check at the first opportunity after the
normal operating temperature of 160F (71C) to
200F (93C) is reached.
6. If the fluid level is in the acceptable range, push the
dipstick back in all the way.

6-29
NOTICE:
We recommend you use only fluid labeled
DEXRON-III, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than
DEXRON
-III is not covered by your new
vehicle warranty.

After adding fluid, recheck the fluid level as
described under ªHow to Check.º

When the correct fluid level is obtained, push the
dipstick back in all the way.
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. See your maintenance schedule to find out
when to change your transmission fluid.
How to Check
Because this operation can be a little difficult, you
may choose to have this done at your GM 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 fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission fluid.
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.

6-30
Then, follow these steps:
5-Speed for VORTEC 4300 V6 and 4800 V8 Engines
Shown, Other Manual Transmissions Similar
1. Remove the filler plug.
2. Check that the lubricant level is up to the bottom of
the filler plug hole.
3. If the fluid level is good, install the plug 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
ªRecommended Fluids and Lubricantsº in the Index.
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of the
filler plug hole.
3. Install the filler plug. Be sure the plug is fully seated.

6-31
Hydraulic Clutch
The hydraulic clutch linkage in your vehicle is
self
-adjusting. The clutch master cylinder reservoir is
filled with hydraulic clutch fluid.
It is not necessary to regularly check clutch fluid unless
you suspect there is a leak in the system. Adding fluid
won't correct a leak.
A fluid loss in this system could indicate a problem.
Have the system inspected and repaired.
When to Check and What to Use
The clutch master cylinder
reservoir is located in the
rear of the engine
compartment on the
driver's side of the vehicle.
See ªEngine Compartment
Overviewº in the Index
for more information
on location.Refer to the Maintenance Schedule to determine how
often you should check the fluid level in your clutch
master cylinder reservoir and for the proper fluid. See
ªOwner Checks and Servicesº and ªRecommended
Fluids and Lubricantsº in the Index.
How to Check and Add Fluid
The proper fluid should be added if the level does not
reach the bottom of the diaphragm when it's in place in
the reservoir. See the instructions on the reservoir cap.