transmission GMC SIERRA 2002 User Guide

2-40
There is a delay in the transition between the daytime
and nighttime operation of the Daytime Running Lamps
(DRL) and the automatic headlamp systems so that
driving under bridges or bright overhead street lights does
not affect the system. The DRL and automatic headlamp
system will only be affected when the light sensor sees a
change in lighting lasting longer than the delay.
To idle your vehicle with the automatic headlamp
system off, set the parking brake while the ignition is
off. Then start your vehicle. The automatic headlamp
system will stay off until you release the parking brake.
You may be able to turn off your automatic headlamp
system. See ªDaytime Running Lamps (DRL)º later in
this section for more information.
As with any vehicle, you should turn on the regular
headlamps if you need them.
Lamps On Reminder
A reminder chime will sound when your headlamps or
parking lamps are manually turned on and your ignition
is in OFF, LOCK or ACCESSORY. To disable the
chime, turn the thumbwheel all the way down. In the
automatic mode, the headlamps turn off once the
ignition key is in OFF.
Daytime Running Lamps
Daytime Running Lamps (DRL) can make it easier
for others to see the front of your vehicle during
the day. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the
short periods after dawn and before sunset. Fully
functional daytime running lamps are required on all
vehicles first sold in Canada.
The DRL system will come on when the following
conditions are met:

The ignition is on,

the exterior lamp control off,

the automatic transmission is not in PARK (P),

the light sensor determines it is daytime and

the parking brake is released.
When the DRL are on, only your DRL lamps will be on.
The taillamps, sidemarker and other lamps won't be on.
The instrument panel won't be lit up either.

2-41
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps or the
last chosen headlamp setting that was used.
When you turn the exterior lamp control to off,
the headlamps will go off, and your DRL lamps will
illuminate, provided it is not dark outside.
To idle your vehicle with the DRL off, set the
parking brake, before starting the vehicle. Shifting the
transmission into PARK (P) will also allow you to idle
the vehicle with the DRL off. The DRL will stay off
until you release the parking brake or shift the
transmission out of PARK (P).
The following procedure applies only to vehicles first
sold in the United States.
When necessary, you may turn off the automatic
headlamp system and the Daytime Running Lamps
(DRL) feature by following these steps. When the system
is turned off, the headlamps will not automatically come
on when it becomes dark outside.1. Turn the ignition to RUN.
2. Press the DOME OVERRIDE button four times
within six seconds. After the fourth press of the
button, a chime will sound informing you the
system is off.
The system will revert back to the automatic mode when
the DOME OVERRIDE button is again pushed four
times within six seconds (a chime will sound), or when
the ignition is turned off and on again.
As with any vehicle, you should turn on the regular
headlamp system when you need it.
Puddle Lamps
Your vehicle is equipped with puddle lamps to help you
see the area near the base of the front doors when it is
dark out. The puddle lamps will illuminate when a door
is opened or when you press the UNLOCK button on the
keyless entry transmitter. You can program the puddle
lamps not to come on if you wish. See ªSecondary
Information Centerº in the Index for more information.

2-57
HomeLink
Transmitter
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference,
and (2) this device must accept any interference received
including interference that may cause undesired operation.
This device complies with RSS
-210 of Industry Canada.
Operation is subject to the following two conditions:
(1) this device may not cause interference, and (2) this
device must accept any interference, including interference
that may cause undesired operation of the device.
Changes and modifications to this system by other than
an authorized service facility could void authorization to
use this equipment.
Programming the HomeLink Transmitter
Do not use the HomeLink Transmitter with any garage
door opener that does not have the ªstop and reverseº
feature. This includes any garage door opener model
manufactured before April 1, 1982.
Be sure that people and objects are clear of the garage
door you are programming.
It is recommended that a new battery be installed in
your hand
-held transmitter for quicker and more
accurate transmission of the radio frequency.
Your vehicle's engine should be turned off while
programming the transmitter. Follow these steps to
program up to three channels:
1. Decide which one of the three channels (one of the
HomeLink buttons) you want to program.
2. Press and hold the desired button on HomeLink
through Step 3.
3. When the HomeLink indicator light begins to blink
slowly (this may take up to 30 seconds), hold the
hand
-held transmitter about 1 to 3 inches (3 to 8 cm)
away from HomeLink and then press and hold the
transmit button on the hand
-held transmitter.
Continue to hold both buttons until the indicator
light on HomeLink begins to flash rapidly
(this may take up to 90 seconds).

2-70 Engine Coolant Temperature Gage
United States Canada
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210
F (100
C) or less. If you are pulling a
load or going up hills, it is normal for the temperature to
fluctuate and approach the 250
F (122
C) mark. If the
gage reaches the 260
F (125
C) mark, it indicates that
the cooling system is working beyond its capacity.
See ªEngine Overheatingº in the Index.
Transmission Temperature Gage
United States Canada
Your vehicle is equipped with a transmission
temperature gage.
When your ignition is on, the gage shows the temperature
of the transmission fluid. The normal operating range is
from 100
F (38
C) to about 265
F (130
C).

2-71
At approximately 265
F (130
C), the message center
will display a TRANS FLUID HOT message and the
transmission will enter a transmission protection mode.
When the transmission enters the protection mode,
you may notice a change in the transmission shifting
patterns. The transmission will return to normal shifting
patterns when the transmission fluid temperature falls
below 260
F (127
C).
See ªMessage Centerº in the Index for further
information.
If the transmission fluid reaches temperatures of
approximately 275
F (135
C) or greater, the message
center will display a TRANS HOT...IDLE ENG warning
message. Pull the vehicle off the roadway when it is safe
to do so. Set the parking brake, place the transmission
in PARK (P) and allow the engine to idle until the
transmission temperature falls below 260
F (127
C).
If the transmission continues to operate above 265
F
(130
C), please contact your nearest dealer or the
GM Roadside Assistance Center.
NOTICE:
If you keep driving your vehicle with the
transmission temperature gage above the
normal operating range, you can damage the
transmission. This could lead to costly repairs
that may not be covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a large or heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler.
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.

2-72 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.
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.

2-78 Trans Fluid Hot
The automatic transmission temperature warning display
is contained in the message center.
If the transmission fluid
temperature becomes high,
the message center will
display this message.
When the transmission enters the protection mode
you may notice a change in the transmission shifting
patterns. When the transmission fluid temperature
returns to normal, the display will turn off and the
transmission shifting patterns will return to normal.
NOTICE:
If you keep driving your vehicle with the
transmission TRANS FLUID HOT message
displayed, you can damage the transmission.
This could lead to costly repairs that may not be
covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a large or heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler.
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.

3-5 Heating
The heater works best if you keep your windows closed
while using it. On cold days, use the floor or bi
-level
modes with the temperature knob in the red area.
On cold days, approximately 32
F (
-0
C) or lower you
may experience differences in how the transmission
shifts until the engine is warm. This feature
automatically reduces the time it takes for the engine to
reach normal operating temperature and shortens the
time it takes the heater to reach full output.
If you use the engine coolant heater before starting your
engine in cold weather, 20
F (
-8
C) or lower, the
heating system will produce warmer air faster to heat the
passenger compartment.
The use of an engine coolant heater also reduces the
time it takes for the engine to reach normal operating
temperature. For more information, see ªEngine Coolant
Heaterº in the Index.
Defogging and Defrosting
On cool, humid days, use blend mode to keep the
windshield and side windows clear. Use defrost mode to
remove fog or ice from the windshield in extremely
humid or cold conditions. Use defrost mode with the
temperature knob toward the red area and the fan knob
turned all the way clockwise.

4-21
Q:What should I do if my vehicle stalls, or is about
to stall, and I can't make it up the hill?
A:If this happens, there are some things you should
do, and there are some things you must not do.
First, here's what you should do:

Push the brake pedal to stop the vehicle and
keep it from rolling backwards. Also, apply the
parking brake.

If your engine is still running, shift the transmission
to REVERSE (R), release the parking brake, and
slowly back down the hill in REVERSE (R).

If your engine has stopped running, you'll need
to restart it. With the brake pedal pressed and the
parking brake still applied, shift the transmission to
PARK (P) and restart the engine. Then, shift to
REVERSE (R), release the parking brake, and
slowly back down the hill as straight as possible
in REVERSE (R).
As you are backing down the hill, put your left hand
on the steering wheel at the 12 o'clock position. This
way, you'll be able to tell if your wheels are straight
and maneuver as you back down. It's best that you
back down the hill with your wheels straight rather
than in the left or right direction. Turning the wheel
too far to the left or right will increase the possibility
of a rollover.
Here are some things you must not do if you stall, or are
about to stall, when going up a hill.

Never attempt to prevent a stall by shifting into
NEUTRAL (N) to ªrev
-upº the engine and regain
forward momentum. This won't work. Your vehicle
will roll backwards very quickly and you could go
out of control.
Instead, apply the regular brake to stop the vehicle. Then
apply the parking brake. Shift to REVERSE (R), release
the parking brake, and slowly back straight down.

Never attempt to turn around if you are about to stall
when going up a hill. If the hill is steep enough to
stall your vehicle, it's steep enough to cause you to
roll over if you turn around. If you can't make it up
the hill, you must back straight down the hill.

4-22
Q:Suppose, after stalling, I try to back down the
hill and decide I just can't do it. What should
I do?
A:Set the parking brake, put your transmission in
PARK (P) and turn off the engine. Leave the
vehicle and go get some help. Exit on the uphill
side and stay clear of the path the vehicle would
take if it rolled downhill.
Driving Downhill
When off-roading takes you downhill, you'll want to
consider a number of things:

How steep is the downhill? Will I be able to maintain
vehicle control?

What's the surface like? Smooth? Rough? Slippery?
Hard
-packed dirt? Gravel?

Are there hidden surface obstacles? Ruts?
Logs? Boulders?

What's at the bottom of the hill? Is there a hidden
creek bank or even a river bottom with large rocks?If you decide you can go down a hill safely, then try to
keep your vehicle headed straight down, and use a low
gear. This way, engine drag can help your brakes and
they won't have to do all the work. Descend slowly,
keeping your vehicle under control at all times.
CAUTION:
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could
cause loss of control and a serious accident.
Apply the brakes lightly when descending a
hill and use a low gear to keep vehicle speed
under control.