Page 633 of 680

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 162.
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 162.
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.
633
Page 634 of 680
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.
634
Page 635 of 680

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 500.
Engine Coolant50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
coolant. SeeEngine Coolant on
page 513.
635
Page 636 of 680