ignition GMC ENVOY XL 2006 Service Manual

Charging System Light
The charging system light
will come on briey when
you turn on the ignition,
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 you are driving, you may have a
problem with the charging system. It could indicate
that you have problems with a generator drive belt,
or another electrical problem. Have it checked
right away. Driving while this light is on could drain
your battery.
If you must drive a short distance with the light on, be
certain to turn off all your accessories, such as the
radio and air conditioner.
Voltmeter Gage
When your engine is not
running, but the ignition is
in RUN, this gage
shows your battery’s state
of charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between the
low and high warning zones indicate the normal
operating range.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left idling for an
extended period. This condition is normal since the
charging system is not able to provide full power
at engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create maximum power.
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You can only drive for a short time with the reading in
either warning zone. If you must drive, turn off all
unnecessary accessories.
Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
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 doesn’t release
fully. If it stays on after your parking brake is fully
released, it means you have 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 isn’t 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 doesn’t come on then, have it
xed so it will be ready to warn you if there’s 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 4-50.
{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
3-39

Anti-Lock Brake System
Warning Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on for
several seconds, that is
normal. A chime may also
sound when the light
comes on.
If the light stays on, or comes on when you are driving,
your vehicle needs service. If the regular brake
system warning light is not on, you still have brakes, but
you do not have anti-lock brakes. If the regular brake
system warning light is also on, you do not have
anti-lock brakes and there is a problem with your regular
brakes. SeeBrake System Warning Light on page 3-39
earlier in this section.
The anti-lock brake system warning light should come
on briey when you turn the ignition key to RUN. If
the light does not come on then, have it xed so it will
be ready to warn you if there is a problem.
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 4-9.
3-40

Malfunction Indicator Lamp
Check Engine Light
Your vehicle has 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 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.
Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls
may not work as well, your fuel economy may not
be as good, and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is
not running. If the light does not come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
3-42

Service Four-Wheel Drive
Warning Light
This light should come on
briey when you turn on
the ignition, as a check to
show you it is working.
The service four-wheel drive 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 GM dealer in
correctly diagnosing a malfunction.
Check Gages Warning Light
The check gages light will
come on briey 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.
Gate Ajar Light
If this light comes on, your
liftgate or liftglass is not
completely shut.
Close the liftgate or liftglass. Never drive with the liftgate
or liftglass even partially open.
3-48

Fuel Gage
When the ignition is on, the fuel gage tells you about
how much fuel you have remaining.
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 ll 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
ll 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 Warning Light
The light next to the fuel gage will come on briey 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. SeeFuel on
page 5-5.
Check Gas Cap Light
If equipped, this light will
come on if your gas cap is
not securely fastened.
SeeMalfunction Indicator Lamp on page 3-42for
more information. United States
Canada
3-49

DIC Operation and Displays
The DIC comes on when the ignition is on. After a short
delay the DIC will display the information that was
last displayed before the engine was turned off.
If a problem is detected, a warning message will appear
on the display. Pressing the trip stem will acknowledge
any warning or service messages. Pressing any of
the DIC steering wheel buttons — trip information, fuel
information, customization, or select button — will
also acknowledge any warnings or service messages.
You should take any message that appears on the
display seriously and remember that clearing the
message will only make the message disappear, not
correct the problem.
The DIC has different modes which can be accessed by
pressing the four DIC buttons located on the steering
wheel. These buttons are trip information, fuel
information, customization, and select. The button
functions are detailed in the following pages.
Trip Information Button
3
(Trip Information):Press the trip information
button to scroll through the ODOMETER, TRIP A,
TRIP B, and TIMER.
Odometer:Press the trip information button until
ODOMETER appears on the display. This mode shows
the total distance the vehicle has been driven in
either miles or kilometers. Pressing the reset stem
located on the instrument cluster with the vehicle off will
also display the odometer.
Trip A:Press the trip information button until TRIP A
appears on the display. This mode shows the current
distance traveled since the last reset for TRIP A in either
miles or kilometers.
Trip B:Press the trip information button until TRIP B
appears on the display. This mode shows the current
distance traveled since the last reset for TRIP B in either
miles or kilometers.
To reset TRIP A or TRIP B information, press and hold
the select button for one second while in one of the
trip modes. This will reset the information for TRIP A
or TRIP B.
3-51

You can also reset the TRIP A or TRIP B while they are
displayed by pressing the reset stem on the cluster. If
you press and hold the reset stem or the select
button for four seconds, the display will show the
distance traveled since the last ignition cycle for TRIP A
or TRIP B.
Timer:The DIC can be used as a timer. Press the
select button while TIMER is displayed to start the timer.
The display will show the amount of time that has
passed since the timer was last reset, not including time
the ignition is off. Time will continue to be counted as
long as the ignition is on, even if another display is being
shown on the DIC. The timer will record up to 99 hours,
59 minutes and 59 seconds (99:59:59) after which
the display will roll back to zero.
To stop the counting of time, press the select button
briey while TIMER is displayed.
To reset the timer to zero, press and hold the select
button while TIMER is displayed.Fuel Information Button
t
(Fuel Information):Press the fuel information
button to scroll through the range, fuel used, average
fuel economy, and the engine oil life system.
Fuel Range:Press the fuel information button until
RANGE appears on the display. This mode shows the
remaining distance you can drive without refueling.
It is based on fuel economy and the fuel remaining in
the fuel tank. The display will show LOW if the fuel
level is low.
The fuel economy data used to determine fuel range is
an average of recent driving conditions. As your
driving conditions change, this data is gradually updated.
Fuel range cannot be reset.
Fuel Used:Press the fuel information button until
FUEL USED appears on the display. This mode shows
the number of gallons or liters of fuel used since the
last reset of this menu item. To reset the fuel used
information, press and hold the select button for
one second while FUEL USED is displayed.
3-52

DIC Warnings and Messages
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 after the other. Some
messages may not require immediate action, but
you should press the trip stem on the instrument panel
cluster to acknowledge that you received the message
and to clear it from the display. Pressing any of the DIC
steering wheel buttons — trip information, fuel
information, customization, or select button — will also
acknowledge any warnings or service messages.
Some messages cannot be cleared from the display
because they are more urgent. These messages require
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.
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 by your GM dealer as soon as possible.
SeeVoltmeter Gage on page 3-38. Press the select
button to acknowledge this message and clear it from
the DIC display.
CHANGE ENGINE OIL
This message is displayed when the engine oil needs to
be changed and service is required for your vehicle.
SeeScheduled Maintenance on page 6-4andEngine
Oil on page 5-16for more information. Also seeEngine
Oil Life System on page 5-20for information on how
to reset the message. This message will clear itself after
10 seconds until the next ignition cycle.
3-54

REAR ACCESS OPEN
If the liftgate or liftglass is open while the ignition is in
RUN, this message will appear on the DIC and you will
hear a chime. Turn off the vehicle and check the
liftgate and liftglass. SeeLiftgate/Liftglass on page 2-13.
Restart the vehicle and check for the message on the
DIC display. Press the select button to acknowledge this
message and clear it from the DIC display.
RIGHT REAR DOOR AJAR
If the passenger’s side rear 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. Press the
select button to acknowledge this message and clear
it from the DIC display.
SERVICE AIR BAG
If there is a problem with the airbag system this
message will be displayed on the DIC. Have your
GM dealer inspect the system for problems. SeeAirbag
Readiness Light on page 3-35andAirbag System on
page 1-58for more information. Press the select button
to acknowledge this message and clear it from the
DIC display.
SERVICE BRAKE SYSTEM
If a problem occurs with the brake system this message
will appear on the DIC. If this message appears, stop
as soon as possible and turn off the vehicle. Restart the
vehicle and check for the message on the DIC display.
If the message is still displayed, or appears again when
you begin driving, the brake system needs service.
See your GM dealer.
SERVICE STABILITRAK
If you ever see the SERVICE STABILITRAK message,
it means there may be a problem with your StabiliTrak®
system. If you see this message, try to reset the
system by performing the following: stop; turn off the
engine; then start the engine again. If the SERVICE
STABILITRAK message still comes on, it means there
is a problem. You should see your GM dealer for
service. The vehicle is safe to drive, however, you do
not have the benet of StabiliTrak
®, so reduce your
speed and drive accordingly. Press the select button
to acknowledge this message and clear it from the
DIC display.
3-57