2004 CHEVROLET TAHOE brake sensor

{CAUTION:
When an air bag inates, there is dust in the
air. This dust could cause breathing problems
for people with a history of asthma or other
breathing trouble. To avoid this, everyone in
the vehicle should get out as soon as it is safe
to do so. If you have breathing problems but
can not get out of the vehicle after an air bag
inates, then get fresh air by opening a
window or a door. If you experience breathing
problems following an air bag deployment, you
should seek medical attention.
In many crashes severe enough to inate an air bag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur from the
right front passenger air bag.
Air bags are designed to inate only once. After an
air bag inates, you’ll need some new parts for your
air bag system. If you don’t get them, the air bag
system won’t be there to help protect you in another
crash. A new system will include air bag modules
and possibly other parts. The service manual for your
vehicle covers the need to replace other parts.
Your vehicle is equipped with electronic frontal
sensors which help the sensing system distinguish
between a moderate and a more severe frontal
impact. Your vehicle is also equipped with a crash
sensing and diagnostic module, which records
information about the frontal air bag system. The
module records information about the readiness of
the system and when the system commands air bag
ination. It records the status of the driver’s safety
belt usage in a crash in which the air bag deploys or
a crash in which the air bag nearly deploys. The
module also records speed, engine rpm, brake and
throttle data.
Let only qualied technicians work on your air bag
systems. Improper service can mean that an air bag
system won’t work properly. See your dealer for
service.
Notice:If you damage the covering for the driver’s
or the right front passenger’s air bag, or the air
bag covering on the driver’s and right front
passenger’s seatback, the air bag may not work
properly. You may have to replace the air bag
module in the steering wheel, both the air bag
module and the instrument panel for the right front
passenger’s air bag, or both the air bag module
and seatback for the driver’s and right front
passenger’s side impact air bag. Do not open or
break the air bag coverings.
1-83

SERVICE TIRE MONITOR
If your vehicle is equipped with the Tire Pressure
Monitor System, this message will be displayed if one or
more of the tire monitor sensors have malfunctioned,
or if all of the tire monitor sensors have not been
programmed successfully. Press the select button or
reset stem, to clear it from the display. The message will
reappear at each ignition cycle until the system has
been serviced.
STABILITY SYS ACTIVE
You may see the STABILITY SYS ACTIVE message on
the DIC. It means that an advanced computer-controlled
system has come on to help your vehicle continue to
go in the direction in which you’re steering.
Stabilitrak
®activates when the computer senses that
your vehicle is just starting to spin, as it might if you hit
a patch of ice or other slippery spot on the road.
When the system activates, you may hear a noise or
feel a vibration in the brake pedal. This is normal. When
the STABILITY SYS ACTIVE message is on, you
should continue to steer in the direction you want to go.
The system is designed to help you in bad weather
or other difficult driving situations by making the most of
whatever road conditions will permit.
STABILITY SYS DISABLED
The STABILITY SYS DISABLED message will turn on
when you press the Stabilitrak®button, or when the
stability control has been automatically disabled. To limit
wheel spin and realize the full benets of the stability
enhancement system, you should normally leave
Stabilitrak
®on. However, you should turn Stabilitrak®off
if your vehicle gets stuck in sand, mud, ice or snow
and you want to “rock” your vehicle to attempt to free it,
or if you are driving in extreme off-road conditions
and require more wheel spin. SeeIf You Are Stuck: In
Sand, Mud, Ice or Snow on page 4-52. To turn the
Stabilitrak
®system back on press the Stabilitrak®button
again. There are several conditions that can cause
this message to appear. One condition is overheating,
which could occur if Stabilitrak
®activates continuously
for an extended period of time. The message will also be
displayed if the brake system warning light is on. See
Brake System Warning Light on page 3-45. The
message could be displayed if the stability system takes
longer than usual to complete its diagnostic checks
due to driving conditions. If an engine or vehicle related
problem has been detected, and the vehicle needs
service, the message will appear. The message will also
appear if the vehicle is shifted into 4LO.
The message will turn off as soon as the conditions that
caused the message to be displayed are no longer
present.
3-74

TPM Sensor Identication Codes
Each TPM sensor has a unique identication code. Any
time you rotate your vehicle’s tires or replace one or more
of the TPM sensors, the identication codes will need to
be matched to the new tire/wheel position. Each tire/
wheel position is matched to a sensor, by increasing or
decreasing the tire’s air pressure. The sensors are
matched to the tire/wheel positions in the following
order: left front (LF); right front (RF); right rear (RR) and
left rear (LR).
You will have one minute to match the rst tire/wheel
position, and ve minutes overall to match all four
tire/wheel positions. If it takes longer than one minute,
to match the rst tire and wheel, or more than ve
minutes to match all four tire and wheel positions the
matching process stops and you will need to start over.
The TPM sensor matching process is outlined below:
1. Set the Parking brake.
2. Turn the ignition switch to RUN with the engine off.
3. Turn the exterior lamp switch from “Off” to “On”
four times within 3 seconds. A double horn
chirp will sound and the TPM low tire warning
light will begin to ash. The double horn
chirp and ashing TPM warning light indicate
that the TPM matching process has started.The TPM warning light should continue ashing
throughout the matching procedure. The SERVICE
TIRE MONITOR message will be displayed on
the Driver Information Center (DIC).
4. Start with the left (driver’s side) front tire.
5. Remove the valve cap from the valve cap stem.
Activate the TPM sensor by increasing or
decreasing the tire’s air pressure for 10 seconds,
then stop and listen for a single horn chirp.
The single horn chirp should sound within
15 seconds, conrming that the sensor identication
code has been matched to this tire and wheel
position. If you do not hear the conrming single
horn chirp, you will need to start over with step
number one. To let air-pressure out of a tire you can
use the pointy end of the valve cap, a pencil-style
air pressure gage or a key.
6. Proceed to the right (passenger’s side) front tire,
and repeat the procedure in step 5.
7. Proceed to the right (passenger’s side) rear tire,
and repeat the procedure in step 5.
8. Proceed to the left (driver’s side) rear tire, and
repeat the procedure in step 5.
9. After hearing the conrming horn chirp for the left
rear tire, check to see if the TPM warning light is
still ashing. If yes, turn the ignition switch to OFF.
5-71

*1— Gasoline Engine and Fuel Injection Rail #2.
*2— Gasoline Engine and Fuel Injection Rail #1.
*3— Gasoline Engine; Oxygen Sensors.
*4— Gasoline Engine; Oxygen Sensors.
*5— PCM Ignition
Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single Battery
and Diesels Only)/Dual Battery
(TP2) Do not install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats, Right
Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet — Rear
Cargo Area and Instrument
Panel
STUD 2Accessory Power/Trailer Wiring
Brake Feed
Fuses Usage
ABS Anti-Lock Brakes
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller
Battery Feed
SUNROOF Sunroof
5-115