2002 GMC ENVOY engine oil

2-22
Engine Coolant Heater (If Equipped)
In very cold weather, 0
F (-18
C) or colder, the
engine coolant heater can help. You'll get easier starting
and better fuel economy during engine warm
-up.
Usually, the coolant heater should be plugged in a
minimum of four hours prior to starting your vehicle.
At temperatures above 32
F (0
C), use of the coolant
heater is not required.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord. The
cord is located on the driver's side of the engine
compartment, behind the underhood fuse block.
3. Plug it into a normal, grounded 110
-volt AC outlet.
CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the wrong
kind of extension cord could overheat and cause
a fire. You could be seriously injured. Plug the
cord into a properly grounded three
-prong
11 0
-volt AC outlet. If the cord won't reach, use a
heavy
-duty three-prong extension cord rated for
at least 15 amps.
4. Before starting the engine, be sure to unplug
and store the cord as it was before to keep it away
from moving engine parts. If you don't, it could
be damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead of
trying to list everything here, we ask that you contact
your dealer in the area where you'll be parking your
vehicle. The dealer can give you the best advice for that
particular area.

2-86
Oil Pressure Gage
United States Canada
The oil pressure gage shows the engine oil pressure in
psi (pounds per square inch) when the engine is running.
Canadian vehicles indicate pressure in kPa (kilopascals).
CAUTION:
Don't keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches fire. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
NOTICE:
Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.
A reading in the low pressure zone may be caused by a
dangerously low oil level or other problems causing low
oil pressure.

2-87
Change Engine Oil Light
United States Canada
This light is displayed when the engine oil needs to
be changed.
Once the engine oil has been changed, the CHANGE
ENG OIL light must be reset. Until it is reset, the light
will be displayed when the engine is on. For more
information on resetting the system, see ªOil Life
Systemº in the Index.
Security Light
United States Canada
This light will come on briefly when you turn the
key toward START. The light will stay on until the
engine starts.
If the light flashes, the Passlock

system has entered a
tamper mode. If the vehicle fails to start, see ªPasslockº
in the Index.
If the light comes on continuously while driving and
stays on, there may be a problem with the Passlock
system. Your vehicle will not be protected by Passlock,
and you should see your dealer.
Also, see ªContent Theft
-Deterrentº in the Index for
additional information regarding the SECURITY light.

2-89
Service Four-Wheel-Drive Warning Light
(If Equipped)
United States Canada
This light should come on briefly when you turn on the
ignition, as a check to show you it is working.
The SERVICE 4WD light comes on to indicate that
there may be a problem with the drive system and
service is required. Malfunctions can be indicated by the
system before any problem is apparent, which may
prevent serious damage to the vehicle. This system is
also designed to assist your service technician in
correctly diagnosing a malfunction.
Check Gages Light
United States Canada
The CHECK GAGES light will come on briefly when
you are starting the engine.
If the light comes on and stays on while you are driving,
check your coolant temperature and engine oil pressure
gages to see if they are in the warning zones.

2-91
Here are four things that some owners ask about.
None of these show a problem with your fuel gage:

At the gas station, the gas pump shuts off before the
gage reads full.

It takes a little more or less fuel to fill up than the
gage indicated. For example, the gage may have
indicated the tank was half full, but it actually took a
little more or less than half the tank's capacity to fill
the tank.

The gage moves a little when you turn a corner or
speed up.

The gage doesn't go back to empty when you turn
off the ignition.
Low Fuel Light
The light next to the fuel gage will come on briefly
when you are starting the engine.
This light comes on when the fuel tank is low on fuel.
To turn it off, add fuel to the fuel tank. See ªFuelº in
the Index.
Driver Information Center (DIC)
(If Equipped)
The DIC display is located on the instrument panel
cluster above the steering wheel. The DIC can display
information such as the trip odometer, fuel economy and
personalization features.
A.Trip Information: This button will display the
odometer, trip odometer and the timer.
B.Fuel Information: This button will display the
current range, average fuel economy, instant fuel
economy and engine oil life.
C.Personalization: This button will change personal
options available on your vehicle.
D.Select: This button resets certain functions and turns
off or acknowledges messages on the DIC.

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GM Oil Life System

Press the fuel information button until ENGINE OIL
LIFE appears in the display. The GM Oil Life System

shows an estimate of the oil's remaining useful life.
It will show 100% when the system is reset after an oil
change. It will alert you to change your oil on a schedule
consistent with your driving conditions.
Always reset the engine oil life after an oil change.
To reset the Oil Life System press and hold the select
button while ENGINE OIL LIFE is displayed.
The DIC does not replace the need to maintain your
vehicle as recommended in the Maintenance Schedule
in this manual. Also, the oil change reminder will not
detect dusty conditions or engine malfunctions that may
affect the oil. Also, the oil change reminder does not
measure how much oil you have in your engine. So, be
sure to check your oil level often. See ªEngine Oilº in
the Index.Personalization Button
You can program certain features to a preferred setting
for up to two people. Press the personalization button
to scroll through the following personalization features.
All of the personalization options may not be available
on your vehicle. Only the options available will be
displayed on your DIC.

ALARM WARNING TYPE

AUTOMATIC LOCKING

AUTOMATIC UNLOCKING

SEAT POSITION RECALL (If Equipped)

PERIMETER LIGHTING

REMOTE LOCK FEEDBACK

REMOTE UNLOCK FEEDBACK

HEADLAMPS ON AT EXIT

TILT MIRROR IN REVERSE (If Equipped)

EASY EXIT SEAT (If Equipped)

DISPLAY UNITS (E/M)

DISPLAY LANGUAGE
The driver's preferences are recalled by pressing the
unlock button on the remote keyless entry transmitter
or by pressing the appropriate memory button 1 or 2
located on the driver's door.

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DIC Warnings and Messages
Warning messages are displayed on the DIC to notify
the driver that the status of the vehicle has changed and
that some action may be needed by the driver to correct
the condition. More than one message may appear at
one time, they will appear one behind the other. Some
messages may not require immediate action but you
should press the select button to acknowledge that you
received the message and clear it from the display.
Some messages cannot be cleared from the display
because they are more urgent. These message required
action before they can be removed from the DIC display.
The following are the possible messages that can be
displayed and some information about them.
ENGINE COOLANT HOT/IDLE ENGINE
If the cooling system temperature gets hot this message
will appear in the DIC and you will hear a chime. Stop
the vehicle and let the engine idle in PARK (P) to allow
the coolant to reach a safe temperature. This message
will clear when the coolant temperature drops to a safe
operating temperature.ENGINE OVERHEATED/STOP ENGINE
(If Equipped)
If the engine cooling system reaches unsafe
temperatures for operation, this message will appear
in the DIC and you will hear a chime. Stop and turn off
the vehicle as soon as it is safe to do so to avoid severe
damage. This message will clear when the engine has
cooled to a safe operating temperature.
OIL PRESSURE LOW/STOP ENGINE
If low oil pressure levels occur this message will be
displayed on the DIC. Stop the vehicle as soon as safely
possible and do not operate it until the cause of the low
oil pressure has been corrected. Check your oil as soon
as possible and have your vehicle serviced.
BATTERY NOT CHARGING
If the battery is not charging during operation this
message will appear on the DIC. Driving with this
problem could drain your battery. Have the electrical
system checked as soon as possible. Pressing the select
button will acknowledge this message and clear it from
the DIC display.

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CHECK OIL LEVEL
If the oil level in the vehicle is low this message will
appear on the DIC. Check the oil level and correct it as
necessary. You may need to need to let the vehicle cool
or warm up and cycle the ignition to be sure this
message will clear. Once the problem is corrected,
pressing the select button will clear this message from
the DIC display.
CHECK WASHER FLUID
If the washer fluid level is low this message will appear
on the DIC. Adding washer fluid will clear the message.
Pressing the select button will acknowledge this
message and clear it from the DIC display.
TRANS HOT IDLE ENGINE
If the transmission fluid in the vehicle gets hot this
message will appear on the DIC. Driving with the
transmission fluid temperature high can cause damage to
the vehicle. Stop the vehicle and let it idle to allow the
transmission to cool. This message will clear when the
fluid temperature reaches a safe level.ICE POSSIBLE
If the outside temperature reaches a level where ice
could form on the roadway, this message may appear
on the DIC. If the temperature rises to a safe level the
message will clear. Pressing the select button will
acknowledge this message and clear it from the
DIC display.
DRIVER DOOR AJAR
If the driver's door is not fully closed this message will
appear on the display and you will hear a chime. Stop
and turn off the vehicle, check the door for obstacles,
and close the door again. Check to see if the message
still appears on the DIC. Pressing the select button
will acknowledge this message and clear it from the
DIC display.