Page 634 of 684

(e)Make sure the safety belt reminder light and all
your belts, buckles, latch plates, retractors, and
anchorages are working properly. Look for
any other loose or damaged safety belt system
parts. If you see anything that might keep a safety
belt system from doing its job, have it repaired.
Have any torn or frayed safety belts replaced. Also
look for any opened or broken airbag coverings,
and have them repaired or replaced. The
airbag system does not need regular maintenance.
(f)Lubricate all key lock cylinders, body door
hinges, hood latch assembly, secondary latch,
pivots, spring anchor, release pawl, tailgate hinges,
tailgate linkage, tailgate handle pivot points,
latch bolt, fuel door hinge, locks, and folding seat
hardware. More frequent lubrication may be
required when exposed to a corrosive
environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better, and not stick or squeak.
(g)Check vent hose at transfer case for kinks and
proper installation. Check to be sure vent hose
is unobstructed, clear, and free of debris.(h)Change automatic transmission uid and lter
if the vehicle Gross Vehicle Weight Rating
(GVWR) is over 8600 lbs or if the vehicle is mainly
driven under one or more of these conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
(i)Drain, ush, and re ll cooling system. This
service can be complex; you should have
your dealer perform this service. See Engine
Coolant on page 514 for what to use. Inspect
hoses. Clean radiator, condenser, pressure cap,
and ller neck. Pressure test the cooling
system and pressure cap.
(j)A uid loss in any vehicle system could indicate
a problem. Have the system inspected and
repaired and the uid level checked. Add uid
if needed.
634
Page 637 of 684

At Least Once a Year
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough
room around the vehicle.
2. Firmly apply both the parking brake and the
regular brake. SeeParking Brake on
page 164.
Do not use the accelerator pedal, and be ready
to turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The
vehicle should start only in PARK (P) or
NEUTRAL (N). If the vehicle starts in any
other position, contact your GM Goodwrench
®
dealer for service.
Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough
room around the vehicle. It should be parked
on a level surface.
2. Firmly apply the parking brake. SeeParking
Brake on page 164.
Be ready to apply the regular brake
immediately if the vehicle begins to move.
3. With the engine off, turn the ignition to RUN,
but do not start the engine. Without applying
the regular brake, try to move the shift
lever out of PARK (P) with normal effort. If the
shift lever moves out of PARK (P), contact
your GM Goodwrench
®dealer for service.
637
Page 638 of 684
Ignition Transmission Lock Check
While parked, and with the parking brake set, try
to turn the ignition to LOCK in each shift lever
position.
The ignition should turn to LOCK only when
the shift lever is in PARK (P).
The ignition key should come out only
in LOCK.
Contact your GM Goodwrench
®dealer if service
is required.
Parking Brake and Automatic
Transmission Park (P) Mechanism Check
{CAUTION:
When you are doing this check, your
vehicle could begin to move. You or
others could be injured and property
could be damaged. Make sure there is
room in front of your vehicle in case it
begins to roll. Be ready to apply the
regular brake at once should the vehicle
begin to move.
638
Page 639 of 684

Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular
brake, set the parking brake.
To check the parking brake’s holding ability:
With the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure
from the regular brake pedal. Do this until the
vehicle is held by the parking brake only.
To check the PARK (P) mechanism’s holding
ability: With the engine running, shift to
PARK (P). Then release the parking brake
followed by the regular brake.
Contact your GM Goodwrench
®dealer if service
is required.
Underbody Flushing Service
At least every spring, use plain water to ush any
corrosive materials from the underbody. Take
care to clean thoroughly any areas where mud and
other debris can collect.
Recommended Fluids and
Lubricants
This maintenance section applies to vehicles with
a gasoline engine. If your vehicle has a diesel
engine, see the maintenance schedule section in
the DURAMAX
®Diesel Engine Supplement.
Fluids and lubricants identi ed below by name,
part number, or speci cation can be obtained from
your dealer.
Usage Fluid/Lubricant
Engine OilEngine oil which meets GM
Standard GM6094M and displays
the American Petroleum Institute
Certi ed for Gasoline Engines
starburst symbol. GM Goodwrench
®
oil meets all the requirements for
your vehicle. To determine the
proper viscosity for your vehicle’s
engine, seeEngine Oil (Gasoline
Engine) on page 502.
Engine Coolant50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
coolant. SeeEngine Coolant on
page 514.
639
Page 640 of 684