Page 144 of 356

2-91
Engine Coolant Temperature Gage
United States Canada
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, your engine is
approaching an overheating condition.
If you have been operating your vehicle under normal
driving conditions, you should pull off the road, stop
your vehicle and turn off the engine as soon as possible.
See ªEngine Overheatingº in the Index.
Malfunction Indicator Lamp (Service
Engine Soon Light in the United States or
Check Engine Light in Canada)
United States Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition and emission
control systems.
This system is called OBD II (On
-Board
Diagnostics
-Second Generation) and is intended to assure
that emissions are at acceptable levels for the life of the
vehicle, helping to produce a cleaner environment. The
SERVICE ENGINE SOON or CHECK ENGINE light
comes on to indicate that there is a problem and service is
required. Malfunctions often will be indicated by the
system before any problem is apparent. This may prevent
more serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Page 209 of 356

4-38 Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much
that they would get hot and no longer work well.
On a long uphill grade, shift down and reduce your
speed to around 45 mph (70 km/h) to reduce the
possibility of engine and transmission overheating.
If you are towing a trailer and you have an automatic
transmission with overdrive, you may prefer to drive in
DRIVE (D) instead of AUTOMATIC OVERDRIVE ()
or, as you need to, a lower gear. Or, if you have a
manual transmission with FIFTH (5) gear and you are
towing a trailer, it is better not to use FIFTH (5) gear.
Just drive in FOURTH (4) or, as you need to, a lower
gear. If you have a manual transmission with SIXTH (6)
gear, drive in FIFTH (5) or, as you need to, a lower gear.
Parking on Hills
CAUTION:
You really should not park your vehicle, with
a trailer attached, on a hill. If something goes
wrong, your rig could start to move. People can
be injured, and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill,
here's how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet, or into gear for a manual transmission.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your parking
brake and then shift to PARK (P) or REVERSE (R)
for a manual transmission.
5. Release the regular brakes.
Page 210 of 356

4-39 When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for
more on this. Things that are especially important
in trailer operation are automatic transmission fluid
(don't overfill), engine oil, axle lubricant, drive belts,
cooling system and brake system. Each of these is
covered in this manual, and the Index will help you
find them quickly. If you're trailering, it's a good idea
to review this information before you start your trip.
Check periodically to see that all hitch nuts and
bolts are tight.
Engine Cooling When Trailer Towing
Your cooling system may temporarily overheat during
severe operating conditions. See ªEngine Overheatingº
in the Index.
Page 211 of 356
5-
5-1
Section 5 Problems on the Road
Here you'll find what to do about some problems that can occur on the road.
5
-2 Hazard Warning Flashers
5
-3 Other Warning Devices
5
-3 Jump Starting
5
-8 Towing Your Vehicle
5
-9 Engine Overheating5
-12 Cooling System
5
-22 If a Tire Goes Flat
5
-23 Changing a Flat Tire
5
-35 Compact Spare Tire
5
-36 If You're Stuck: In Sand, Mud, Ice or Snow
Page 219 of 356

5-9
Engine Overheating
You will find a coolant temperature gage on your
instrument panel cluster. See ªEngine Coolant
Temperature Gageº in the Index.
Overheated Engine Protection
Operating Mode
This emergency operating mode allows your vehicle
to be driven to a safe place in an emergency situation.
If an overheated engine condition exists, an overheat
protection mode which alternates firing groups of
cylinders helps prevent engine damage.In this mode, you will notice a significant loss in power
and engine performance. The low coolant light may
come on and the temperature gage will indicate an
overheat condition exists. Driving extended miles (km)
and/or towing a trailer in the overheat protection mode
should be avoided.NOTICE:
After driving in the overheated engine protection
operating mode, to avoid engine damage, allow
the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair
the cause of coolant loss, change the oil and reset
the oil life system. See ªEngine Oilº in the Index.
Page 223 of 356

5-13
If it isn't, you may have a leak at the pressure cap in the
radiator hoses, heater hoses, radiator, water pump or
somewhere else in the cooling system.
CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Don't touch them.
If you do, you can be burned.
Don't run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
If there seems to be no leak, with the engine on,
check to see if the electric engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they aren't, your vehicle needs service.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index.
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.
Page 273 of 356

6-27 What to Use
Standard Differential
Use SAE 75W
-90 Synthetic Gear Lubricant
(GM Part No. 12378261) or equivalent meeting
GM Specification 9986115.
Limited
-Slip Differential
To add lubricant when the level is low, use SAE 75W
-90
Synthetic Gear Lubricant (GM Part No. 12378261) or
equivalent meeting GM Specification 9986115. To
completely refill after draining, add 4 ounces (118 ml)
of Limited
-Slip Differential Lubricant Additive (GM
Part No. 1052358) or equivalent. Then fill to the bottom
of the filler plug hole with the Synthetic Gear Lubricant.
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating or if you need to add coolant to your
radiator, see ªEngine Overheatingº in the Index.A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:
Give freezing protection down to
-34F (-37C).
Give boiling protection up to 265F (129C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
NOTICE:
When adding coolant, it is important that you use
only DEX
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL is added to the
system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.
Page 275 of 356

6-29 Checking Coolant
See ªEngine Compartment Overviewº in the Index for
information on location.
The vehicle must be on a level surface. When your engine
is cold, check the dipstick on the cap of the coolant
recovery tank. The coolant level should be at COLD, or a
little higher. When your engine is warm, the level on the
dipstick should be up to HOT, or a little higher.
Adding Coolant to the Recovery Tank
If you need more coolant, add the proper DEX
-COOL
coolant mixture at the coolant recovery tank, but only
when your engine is cool. If the tank is very low or
empty, also add coolant to the radiator. See ªEngine
Overheatingº in the Index for information.
CAUTION:
Turning the radiator 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 pressure cap
-- even a
little
-- when the engine and radiator are hot.
Add coolant mixture at the recovery tank, but be careful
not to spill it.
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. Don't spill coolant on a hot engine.
Occasionally check the coolant level in the radiator. For
information on how to add coolant to the radiator, see
ªCooling Systemº in the Index.