page 5 GMC ENVOY 2008 Repair Manual

EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator’s output
and the vehicle’s electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands
of some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels of
corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC) message
might be displayed, such as Battery Saver Active or
Service Battery Charging System. If this message is
displayed, it is recommended that the driver reduce the
electrical loads as much as possible. SeeDIC Warnings
and Messages on page 3-53.Battery Run-Down Protection
This feature shuts off the dome, courtesy, and vanity
lamps if they are left on for more than 20 minutes
when the ignition is off. This will keep the battery
from running down.
If the battery run-down protection shuts off the interior
lamps, it may be necessary to do one of the following to
return to normal operation:
Shut off all lamps and close all doors.
Turn the ignition key to RUN.
This feature will also turn off the parking lamps and
headlamps under most circumstances, if they are left on.
If you would like to turn them back on, turn the exterior
lamps knob.
3-19

Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something
is wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention
to your warning lights and gages could also save you
or others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle’s functions. As you
will see in the details on the next few pages, some
warning lights come on briey when you start the engine
just to let you know they’re working. If you are familiar
with this section, you should not be alarmed when
this happens.Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages and
warning lights work together to let you know when there’s
a problem with your vehicle.
When one of the warning lights comes on and stays
on when you are driving, or when one of the gages
shows there may be a problem, check the section
that tells you what to do about it. Please follow this
manual’s advice.
Waiting to do repairs can be costly—and even
dangerous. So please get to know your warning
lights and gages. They’re a big help.
Your vehicle may also have a Driver Information
Center (DIC) that works along with the warning lights
and gages. SeeDriver Information Center (DIC)
on page 3-49.
3-30

Speedometer and Odometer
The speedometer lets you see your speed in both miles
per hour (mph) and kilometers per hour (km/h).
The odometer shows how far your vehicle has been
driven, in either miles (used in the United States)
or kilometers (used in Canada).
The odometer mileage can be checked without the
vehicle running. Press the trip stem located on
the instrument panel cluster.
If your vehicle needs a new odometer installed, the new
one will be set to the correct mileage total of the old
odometer.
Trip Odometer
The trip odometer can tell you how far your vehicle has
been driven since you last set the trip odometer to zero.
The odometer works together with the Driver Information
Center (DIC). You can set a Trip A and Trip B odometer.
See “Trip Information” underDIC Operation and Displays
on page 3-50.
The odometer mileage can be checked without the
vehicle running. Press the trip stem on the instrument
panel cluster.
Tachometer
The tachometer displays
the engine speed in
revolutions per
minute (rpm).
Safety Belt Reminders
Safety Belt Reminder Light
When the engine is started, a chime will come on for
several seconds to remind people to fasten their safety
belts, unless the driver’s safety belt is already buckled.
The safety belt light will
also come on and stay on
for several seconds, then it
will ash for several more.
3-32

This chime and light is repeated if the driver remains
unbuckled and the vehicle is in motion. If the driver’s belt
is already buckled, neither the chime nor the light will
come on.
Passenger Safety Belt Reminder Light
Several seconds after the engine is started, a chime will
sound for several seconds to remind the front passenger
to buckle their safety belt. This would only occur if the
passenger airbag is enabled. SeePassenger Sensing
System on page 1-61for more information. The
passenger safety belt light, located on the instrument
panel, will come on and stay on for several seconds and
then ash for several more.
This chime and light are
repeated if the passenger
remains unbuckled and
the vehicle is in motion.
If the passenger’s safety belt is buckled, neither the
chime nor the light will come on.
Airbag Readiness Light
There is an airbag readiness light on the instrument panel
cluster, which shows the airbag symbol. The system
checks the airbag’s electrical system for malfunctions.
The light tells you if there is an electrical problem.
The system check includes the airbag sensor, the
pretensioners, the airbag modules, the wiring and
the crash sensing and diagnostic module. For more
information on the airbag system, seeAirbag System
on page 1-53.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds. The
light should go out and
the system is ready.
3-33

If the airbag readiness light stays on after you start the
vehicle or comes on when you are driving, your airbag
system may not work properly. Have your vehicle
serviced right away.
{CAUTION:
If the airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help avoid
injury to yourself or others, have your vehicle
serviced right away if the airbag readiness light
stays on after you start your vehicle.
The airbag readiness light should ash for a few
seconds when you start the engine. If the light does
not come on then, have it xed immediately. If there
is a problem with the airbag system, an airbag Driver
Information Center (DIC) message may also come
on. SeeDIC Warnings and Messages on page 3-53for
more information.
Passenger Airbag Status Indicator
Your vehicle has the passenger sensing system.
Your rearview mirror has a passenger airbag status
indicator.
When you start the vehicle, the passenger airbag status
indicator will light ON and OFF, or the symbol for on
and off, for several seconds as a system check.United States
Canada
3-34

Then, after several more seconds, the status indicator
will light either ON or OFF, or either the on or off symbol
to let you know the status of the right front passenger’s
frontal airbag.
If the word ON or the on symbol is lit on the passenger
airbag status indicator, it means that the right front
passenger’s frontal airbag is enabled (may inate).
{CAUTION:
If the on indicator comes on when you have a
rear-facing child restraint installed in the right
front passenger’s seat, it means that the
passenger sensing system has not turned off
the passenger’s frontal airbag. A child in a
rear-facing child restraint can be seriously
injured or killed if the right front passenger’s
airbag inates. This is because the back of the
rear-facing child restraint would be very close
to the inating airbag. Do not use a rear-facing
child restraint in the right front passenger’s
seat if the airbag is turned on.
{CAUTION:
Even though the passenger sensing system is
designed to turn off the right front passenger’s
frontal airbag if the system detects a rear-facing
child restraint, no system is fail-safe, and no
one can guarantee that an airbag will not deploy
under some unusual circumstance, even
though it is turned off. We recommend that
rear-facing child restraints be secured in the
rear seat, even if the airbag is off.
If the word OFF or the off symbol is lit on the airbag
status indicator, it means that the passenger sensing
system has turned off the right front passenger’s frontal
airbag. SeePassenger Sensing System on page 1-61
for more on this, including important safety information.
3-35

If, after several seconds, both status indicator lights
remain on, or if there are no lights at all, there may
be a problem with the lights or the passenger sensing
system. See your dealer/retailer for service.
{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on,
it means that something may be wrong with
the airbag system. If this ever happens, have
the vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the airbag(s). SeeAirbag Readiness Light
on page 3-33for more on this, including
important safety information.
Charging System Light
This light will come on
briey when you turn on the
ignition key, but the engine
is not running, as a check
to show you it is working.
It should go out once the engine is running. If it stays
on, or comes on while driving, there could be a problem
with the charging system. A charging system Driver
Information Center (DIC) message may also appear.
SeeDIC Warnings and Messages on page 3-53for
more information. This light could indicate that there
are problems with a generator drive belt, or that there is
an electrical problem. Have it checked right away. If you
must drive a short distance with the light on, be certain
to turn off all the accessories, such as the radio and air
conditioner.
3-36

Brake System Warning Light
When the ignition is on, the brake system warning light
will come on when you set your parking brake. The light
will stay on if your parking brake does not release fully.
If it stays on after your parking brake is fully released, it
means your vehicle has a brake problem. A chime may
also sound when the light comes on.
Your vehicle’s hydraulic brake system is divided into
two parts. If one part is not working, the other part can
still work and stop you. For good braking, though,
you need both parts working well.
If the warning light comes on, there could be a brake
problem. Have your brake system inspected right away.This light should come on briey when you turn the
ignition key to RUN. If it does not come on then, have it
xed so it will be ready to warn you if there is a problem.
If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal
is harder to push or the pedal may go closer to the
oor. It may take longer to stop. If the light is still on,
have the vehicle towed for service. SeeTowing
Your Vehicle on page 4-40.
{CAUTION:
Your brake system may not be working
properly if the brake system warning light is on.
Driving with the brake system warning light on
can lead to an accident. If the light is still on
after you have pulled off the road and stopped
carefully, have the vehicle towed for service.
United States
Canada
3-38

Antilock Brake System
Warning Light
For vehicles with
the Antilock Brake
System (ABS), this light
comes on briey when
the engine is started.
That is normal. If the light does not come on then, have
it xed so it will be ready to warn you if there is a problem.
If the ABS light stays on, turn the ignition off, if the light
comes on when you are driving, stop as soon as it is
safely possible and turn the ignition off. Then start the
engine again to reset the system. If the ABS light still
stays on, or comes on again while you are driving,
your vehicle needs service. If the regular brake system
warning light is not on, your vehicle still has brakes, but
not antilock brakes. If the regular brake system warning
light is also on, your vehicle does not have antilock
brakes and there is a problem with the regular brakes.
SeeBrake System Warning Light on page 3-38.
For vehicles with a Driver Information Center (DIC),
seeDIC Warnings and Messages on page 3-53for
all brake related DIC messages.
StabiliTrak®Service Light
This light will come on
briey when the engine
is started.
This light will come on if a problem is detected in the
StabiliTrak
®system.
For more information seeStabiliTrak
®System on
page 4-6.
3-39

StabiliTrak®Indicator Light
This warning light should
come on briey when the
engine is started.
During most driving conditions, this light will not come
on. If the StabiliTrak
®System is actively controlling
the stability and/or traction of the vehicle, this light
will ash. This is normal.
This light will come on if any portion of the system
has been manually turned off or a problem is detected
in the system.
If your vehicle has a Driver Information Center, a
message will appear also, seeDIC Warnings and
Messages on page 3-53andStabiliTrak
®System on
page 4-6for more information.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
If the gage pointer moves into the red area, it means that
the engine coolant has overheated. 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.
SeeEngine Overheating on page 5-28for more
information.
United StatesCanada
3-40