2001 GMC JIMMY sensor

1-45
Q:Is there anything I might add to the front or
sides of the vehicle that could keep the air bags
from working properly?
A:Yes. If you add things that change your vehicle's
frame, bumper system, front end or side sheet
metal or height, they may keep the air bag system
from working properly. Also, the air bag system
may not work properly if you relocate any of the
air bag sensors. If you have any questions about
this, you should contact Customer Assistance
before you modify your vehicle. The phone
numbers and addresses for Customer Assistance
are in Step Two of the Customer Satisfaction
Procedure in this manual. See ªCustomer
Satisfaction Procedureº in the Index.
Q:What if I add a snow plow? Will it keep the air
bags from working properly?
A:We've designed our air bag systems to work
properly under a wide range of conditions,
including snow plowing with vehicles equipped
with the optional Snow Plow Prep Package
(RPO VYU). But don't change or defeat the
snow plow's ªtripping mechanism.º If you do,
it can damage your snow plow and your vehicle,
and it may cause an air bag inflation.

2-46 Automatic Headlamp System
When it is dark enough outside, your automatic
headlamp system will turn on your headlamps at the
normal brightness along with other lamps such as the
taillamps, sidemarker, parking lamps and the instrument
panel lights. The radio lights will also be dim.
Your vehicle is equipped with a light sensor located on
the top of the instrument panel in the defroster grille.
Be sure it is not covered, or the system will be on
whenever the ignition is on.
The system may also turn on your headlamps when
driving through a parking garage, heavy overcast
weather or a tunnel. This is normal.
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.
As with any vehicle, you should turn on the regular
headlamp system when you need them.
You may be able to turn off your Automatic Headlamp
System. See ªDaytime Running Lamps (DRL)º later in
this section for more information.
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.

2-47 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 lamps control is in automatic
headlamp mode,

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.
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 headlamp switch off, the headlamps
will go off, and your DRL lamps will illuminate,
provided it is not dark outside.To idle an automatic transmission equipped vehicle
with the DRL off, set the parking brake. 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).
This 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 headlights 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 ignition is turned off and on again.
3. To return to the automatic mode, push the DOME
OVERRIDE button four times within six seconds
(the chime will sound), or turn the ignition off and
on again.
As with any vehicle, you should turn on the regular
headlamp system when you need it.

2-74
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 also has a driver information system that
works along with the warning lights and gages. See
ªMessage Centerº in the Index.
Safety Belt Reminder Light
When the key is turned to RUN or START, a chime will
come on for about six 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.
Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the air bag symbol. The system
checks the air bag's electrical system for malfunctions.
The light tells you if there is an electrical problem.
The system check includes the air bag sensors, the air
bag modules, the wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, see ªAir Bagº in the Index.
This light will come on
when you start your vehicle,
and it will flash for a few
seconds. Then the light
should go out. This means
the system is ready.
If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air bag
system may not work properly. Have your vehicle
serviced right away.

3-6
When both the fan control and mode knobs are in the
AUTO position, the system will then automatically
maintain the desired cabin temperature as selected.
Manual control of functions is also available.
Temperature Knob
The middle knob on the control panel lets you select the
desired air temperature in your vehicle. This knob will
allow you to adjust the interior air temperature
independent of the function knob setting. Move the knob
clockwise toward 82
F (28
C) for warmer air. Move the
knob counterclockwise toward 66
F (19
C) for cooler
air. When the system is set for automatic operation,
sensors will control the fan speed.
Full Hot: If you turn the temperature knob past 82
F
(28
C), the system will go into the ªfull hotº mode. The
system will remain at that maximum heating setting and
the fan will blow at the speed the fan knob is set to. If
the fan is in AUTO, it will run at full speed.
Full Cold: If you turn the temperature knob past 66
F
(19
C), the system will go into the ªfull coldº mode.
The system will remain at that maximum cooling setting
and the fan will blow at the speed the fan knob is set to.
If the fan is in AUTO, it will run at full speed.Mode Knob -- Manual Operation
The right knob on the control panel allows you to
choose the direction of air delivery.
You can choose to set the climate control system
yourself, or let the system work for you by placing the
system in AUTO mode. See ªMode Knob
-- Automatic
Operationº later in this section.
(Vent): This setting directs most of the air through
the instrument panel outlets and a small amount through
the floor outlets.
(Bi-Level): Air is delivered through the floor
outlets as well as the instrument panel outlets.
(Floor): This setting directs most of the warmed
air through the floor outlets and some air through the
windshield defroster outlets.
(Blend): Airflow is divided equally between the
floor outlet and the windshield defroster outlets. The air
conditioning compressor may run to dehumidify the air
to prevent window fogging.

3-7
(Defrost): This setting directs most of the air
through the windshield defroster outlets with air flow
also delivered from the side window and floor outlets.
When in defrost mode, the air conditioning compressor
may run to assist in dehumidifying the air and limit
window fogging.
Mode Buttons
(Outside Air): Press this button to force the
system to use outside air. Press is again to close off the
outside air.
Pressing the outside air button will cancel the
recirculation button.
(Recirculation): Press this button to limit the
amount of outside air entering your vehicle. This is
helpful when you are trying to limit odors entering your
vehicle or attempting to quickly cool down the interior.
Recirculation may be selected with the fan control in
OFF to limit odors, outside air and dust from entering
your vehicle.
Pressing the recirculation button will cancel the outside
air button.
A/C (Air Conditioning):Press this button to turn
the air conditioning on and off. The system will cool and
dehumidify the air inside the vehicle when the A/C light
is on. When in AUTO, the A/C is automatically engaged
when necessary.
Air conditioning will be automatically disabled when
the outside air temperature drops below a level at which
air conditioning is ineffective.
Mode Knob
-- Automatic Operation
When the system is set for automatic operation,
sensors will control the air delivery mode. Air will
come primarily from the floor or instrument panel
outlets, with some air directed to the windshield to
prevent fogging.
When the system is in AUTO mode, the air conditioning
light will turn on, and the recirculation and outside air
lights turn off. With the system in full auto control
(both the fan and mode knobs in AUTO), you still have
the ability to override any function. However, continually
overriding the outside air or the A/C compressor will limit
the ability of the system to cool the vehicle quickly.

3-8
If you push a button for a function which is not
available, the light next to that button will flash three
times to alert you that it's not available.
To find your comfort zone, start with the 74
F (23
C)
setting and allow about 20 minutes for the system to
adjust the temperature if necessary.
With the automatic setting, the air conditioning
compressor automatically cycles when needed to cool
the air. In cold weather, when the system senses the need
for heat, the airflow will be directed out of the floor
outlets. As the interior temperature approaches a desired
setting, the fan speed will decrease. To maintain interior
comfort, the airflow will adjust between the instrument
panel air outlets and floor outlets. On bright sunny days
in cool weather, the airflow may come out of the air
conditioning and floor outlets (bi
-level mode) to
maintain comfort and prevent stuffiness.To avoid blowing cold air in cold weather, the system will
delay turning on the fan until warm air is available. The
length of delay depends on the outside air temperature,
engine coolant temperature or the time since the engine
was last started. As the coolant warms up, the fan speed
will gradually increase and air will flow from the floor
outlets, with some airflow to the windshield to prevent
fogging under most normal conditions.
Be careful not to put anything over the solar sensor
located around the center of the instrument panel.
This sensor is used by the automatic system to
regulate temperature.

6-76
Fuse Usage
ATC Automatic Transfer Case
RR DEFOG Rear Window Defogger, Heated
Mirrors (Relay)
RTD Autoride
(Real Time Damping)
RR PRK Right Rear Parking Lamps
ECM B PCM
F/PMP Fuel Pump (Relay)
O2 A Oxygen Sensors
O2 B Oxygen Sensors
LR PRK Left Rear Parking Lamps
RR DEFOG Rear Window Defogger,
Heated Mirrors
HDLP Headlamps (Relay)
TRL PRK Parking Lamps Trailer Wiring
PRIME Not Used
RT HDLP Right Headlamps
DRL Daytime Running Lamps (Relay)
HTD MIR Heated MirrorsFuse Usage
LT HDLP Left Headlamps
A/C Air Conditioning
AUX PWR Cigarette Lighter, Auxiliary
Power Outlets
SEO 2 Special Equipment Option Power,
Power Seats, Aux Roof Mnt Lamp
SEO 1 Special Equipment Option
Power, Aux Roof Mnt Lamp,
Cell Phone, OnStar


DRL Daytime Running Lamps
A/C A/C (Relay)
FOG LP Fog Lamps
FOG LP Fog Lamps (Relay)
RADIO Audio System, Instrument Cluster,
Climate Control System
CIGAR Cigarette Lighter, Auxiliary
Power Outlets
RT TURN Right Turn Signals
BTSI Automatic Transmission Shift
Lock Control System