2001 CHEVROLET ASTRO sensor

1-33 Servicing Your Air Bag-Equipped Vehicle
Air bags affect how your vehicle should be serviced.
There are parts of the air bag system in several places
around your vehicle. You don't want the system to
inflate while someone is working on your vehicle. Your
dealer and the service manual have information about
servicing your vehicle and the air bag system. To
purchase a service manual, see ªService and Owner
Publicationsº in the Index.
CAUTION:
For up to 10 minutes after the ignition key is
turned off and the battery is disconnected, an air
bag can still inflate during improper service. You
can be injured if you are close to an air bag when
it inflates. Avoid wires wrapped with yellow tape
or yellow connectors. They are probably part of
the air bag system. Be sure to follow proper
service procedures, and make sure the person
performing work for you is qualified to do so.
The air bag system does not need regular maintenance.
Adding Equipment to Your Air
Bag-Equipped Vehicle
Q:If I add a push bumper or a bicycle rack to the
front of my vehicle, will it keep the air bags
from working properly?
A:As long as the push bumper or bicycle rack is
attached to your vehicle so that the vehicle's basic
structure isn't changed, it's not likely to keep the
air bags from working properly in a crash.
Q:Is there anything I might add to the front 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 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.

2-42 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 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.
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
headlamp system when you need it.
Lamps On Reminder
A reminder tone will sound when your headlamps or
parking lamps are manually turned on and your ignition is
in OFF, LOCK or ACCESSORY. To disable the tone, turn
the thumbwheel all the way down. In the automatic mode,
the headlamps turn off once the ignition key is in OFF.

2-43 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 lights are required on all
vehicles first sold in Canada.
The DRL system will make your headlamps come on at a
reduced brightness when the following conditions are met:

The ignition is on,

the headlamp switch 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.
Your 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.To idle your vehicle with the DRL off, put the
transmission in PARK (P). The DRL will stay off until
you shift out of PARK (P).
The following does not apply to vehicles first sold in
Canada, and to some early production vehicles.
When necessary, you may turn off the automatic
headlamp system and the Daytime Running
Lamps (DRL) feature by following the steps below:

Turn the ignition to RUN.

Press the DOME OVERRIDE button four times
within six seconds. After the fourth press of the
button, a chime will sound informing you that the
system is off.

To return to the automatic mode, push the DOME
OVERRIDE button four times within six seconds
(the chime will sound), or turn the ignition to
OFF and then to RUN again.
As with any vehicle, you should turn on the regular
headlamp system when you need it.

2-66 Safety Belt Reminder Light
When the key is turned to RUN or START, a tone 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 tone
nor the light will come on.
Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows AIR BAG or 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 sensor,
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.
United States Canada
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.

6-66
Fuse/Circuit
BreakerUsage
HORN Horn Relay and Horn
A/C COMP A/C Enable Relay and Compressor
RR HTR/AC Rear Heater and A/C
ATC Active Transfer Case
-L Van
FRT HVAC Front Heater and A/C
ENG
-I Oxygen Sensors, Camshaft
Position Sensor, Mass Air Flow
Sensor, Evaporative Emission
Canister Vent Solenoid
IGN
-E A/C Enable Relay Coil
ECM
-I Fuel Injectors 1-6, Crankshaft
Position Sensor, VCM, Coil
Driver Module (EST),
Ignition Coil
Blank Not Used
RH HDLMP Right Headlamp
LH Headlamp Left HeadlampFuse/Circuit
BreakerUsage
Blank Not Used
Blank Not Used
DIODE
-1 A/C
Blank Not Used
Blank Not Used
Blank Not Used
LIGHTING Courtesy Fuse, Pwr. Adj. Mirrors
Fuse, TBC
-Battery Fuse
BATT Power ACCY CB, Stop/Hazard
Fuse, Auxiliary Power Fuse,
Cigarette Lighter Fuse, Radio
Battery Fuse
IGN A Starter Relay, Ignition Switch
IGN B Ignition Switch
ABS Electronic Brake Control Module
Blank Not Used
RAP Radio Accy, Power Windows
HTD MIR/RR
DEFOGRear Window Defogger, HVAC
Control Head