2001 GMC ENVOY check engine light

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Testing the Alarm
The alarm can be tested by following these steps:
1. From inside the vehicle, lower the driver's window
and open the driver's door.
2. Activate the system by locking the doors with the
power door lock switch (while the door is open), or
with the keyless entry transmitter (with the door
open or closed).
3. Get out of the vehicle, close the door and wait for
the SECURITY light to go out.
4. Then reach in through the window, unlock the
door with the manual door lock and open the door.
This should set off the alarm.
If the alarm does not sound when it should, but the
vehicle's headlamps flash, check to see if the horn
works. The horn fuse may be blown. To replace the
fuse, see ªFuses and Circuit Breakersº in the Index.
If the alarm does not sound or the vehicle's headlamps
do not flash, the vehicle should be serviced by a dealer.
Passlock

Your vehicle is equipped with the Passlock
theft
-deterrent system.
Passlock is a passive theft
-deterrent system. Passlock
enables fuel if the ignition lock cylinder is turned with a
valid key. If a correct key is not used or the ignition lock
cylinder is tampered with, fuel is disabled.
During normal operation, the SECURITY light will go
off approximately five seconds after the key is turned
to RUN.
If the engine stalls and the SECURITY light flashes,
wait about 10 minutes until the light stops flashing
before trying to restart the engine. Remember to release
the key from START as soon as the engine starts.
If the engine does not start after three tries, the vehicle
needs service.
If the engine is running and the SECURITY light
comes on, you will be able to restart the engine if you
turn the engine off. However, your Passlock system is
not working properly and must be serviced by your
dealer. Your vehicle is not protected by Passlock at
this time. You may also want to check the fuse
(see ªFuses and Circuit Breakersº in the Index).
See your dealer for service.
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The light will be red in the event of an OnStar system
malfunction. If this occurs press the OnStar button to
attempt to contact an advisor. If the connection is made,
the advisor will assist you with steps to take to make
sure that the system is functioning properly. If you
cannot contact the advisor, take your vehicle to your
dealership as soon as possible for assistance.
Safety and Security Services

Automatic Notification of Air Bag
Deployment
-- If an air bag deploys, a priority
emergency signal is automatically sent to the center.
An advisor will locate your vehicle's position, try to
contact you and assist you in the situation. If the
center is unable to contact you, an emergency service
provider will be contacted.

Stolen Vehicle Tracking
-- Call the center at
1
-888-4-ONSTAR (1-888-466-7827) to report your
vehicle stolen. The system can then locate and track
your vehicle and the advisor will be able to notify
the proper authorities.

Roadside Assistance with Location
-- For vehicle
breakdowns, press the OnStar button. An advisor
will contact the appropriate help.
Remote Diagnostics
-- If an instrument panel light
comes on, the center can perform a check of the
engine on
-board computer. An advisor can then
recommend what action needs to be taken.

OnStar MED
-NET -- Med-Net can store your
personal medical history and provide it to emergency
personnel if necessary.

Accident Assist
-- An advisor can provide
step
-by-step guidance following an accident.

Remote Door Unlock
-- To contact the center,
call 1
-888-4-ONSTAR. You will be required to
provide your security information. An advisor will
send a command to your vehicle to unlock itself.
The advisor can delay unlocking your vehicle.
Remote Door Unlock is disabled 48 hours after
the vehicle is parked to maintain the battery charge.

Vehicle Locator Service
-- To contact the center,
call 1
-888-4-ONSTAR. You will be required to
provide your security information. An advisor will
send a command to your vehicle to sound the horn
and/or flash the lamps.
In order to provide you with excellent service, calls with
the OnStar Center may be monitored or recorded.
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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 briefly 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.
Safety Belt Reminder Light
When the key is turned to RUN or START, a chime will
come on for about eight 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 about 20 seconds,
then it will flash for
about 55 seconds.
If the driver's belt is already buckled, neither the chime
nor the light will come on.
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Charging System Indicator Light
The charging system light
will come on briefly 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 on (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 at an idle 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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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 too hot!
It means that your 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.
See ªEngine Overheatingº in the Index for
more information.
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.
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NOTICE:
If you keep driving your vehicle with this light
on, after a while, 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:
Modifications 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 the SERVICE ENGINE SOON
OR CHECK ENGINE light to come on.
Modifications 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.
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 doesn't come on, have it repaired.
This light will also come on during a malfunction in one
of two ways:

Light Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control
system malfunction has been detected on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:

Reducing vehicle speed.

Avoiding hard accelerations.

Avoiding steep uphill grades.

If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stops flashing and remains on steady,
see ªIf the Light Is On Steadyº following.
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If the light continues to flash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart the
engine. If the light remains on steady, see ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully
install the cap. See ªFilling Your Tankº in the Index.
The diagnostic system can determine if the fuel cap
has been left off or improperly installed. A loose or
missing fuel cap will allow fuel to evaporate into the
atmosphere. A few driving trips with the cap properly
installed should turn the light off.Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
See ªFuelº in the Index. Poor fuel quality will cause
your engine not to run as efficiently as designed.
You may notice this as stalling after start
-up, stalling
when you put the vehicle into gear, misfiring, hesitation
on acceleration or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the light
to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
have your dealer or qualified service center check the
vehicle. Your dealer has the proper test equipment and
diagnostic tools to fix any mechanical or electrical
problems that may have developed.
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Emissions Inspection and Maintenance Programs
Some state/provincial and local governments have or may
begin programs to inspect the emission control equipment
on your vehicle. Failure to pass this inspection could
prevent you from getting a vehicle registration.
Here are some things you need to know in order to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the
SERVICE ENGINE SOON or CHECK ENGINE
light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on
-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen
if you have recently replaced your battery or if your
battery has run down. The diagnostic system is designed
to evaluate critical emission control systems during
normal driving. This may take several days of routine
driving. If you have done this and your vehicle still
does not pass the inspection for lack of OBD system
readiness, see your dealer or qualified service center to
prepare the vehicle for inspection.
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.
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