2005 GMC YUKON brake sensor

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.
To turn off the automatic headlamp system, turn the
exterior lamps switch to the off position and then
release. Turning off the automatic headlamp system
with the headlamp switch is not available for vehicles
rst sold in Canada. For vehicles rst sold in Canada,
you can turn off the automatic headlamp system
when parked at night by applying the parking brake
before starting your vehicle. The headlamps will remain
off once the vehicle is started for as long as you are
parked. If you release the parking brake, the lights will
turn on. If the parking brake is not released before
you begin to drive, the exterior lamps will turn on
above 2 mph (3.2 km/h).
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.
If you start your vehicle in a dark garage, the automatic
headlamp system will come on immediately. Once
you leave the garage, it will take approximately
one minute for the automatic headlamp system to
change to DRL if it is bright enough outside. During that
delay, your instrument panel cluster may not be as
bright as usual. Make sure your instrument panel
brightness control is in the full bright position. See
Instrument Panel Brightness on page 3-18.
To idle your vehicle with the automatic headlamp
system off, turn the control to the off position.
You may be able to turn off your Automatic Headlamp
System. SeeDaytime Running Lamps (DRL) on
page 3-15for more information.
Your headlamps will also stay on after you exit the
vehicle. You can program this feature using the Driver
Information Center (DIC). SeeDIC Vehicle
Customization on page 3-68.
As with any vehicle, you should turn on the regular
headlamp system when you need them.
3-16

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. See your GM dealer. Pressing any of the
four DIC buttons, if equipped, will acknowledge the
message and clear it from the DIC display. If your vehicle
is not equipped with the four DIC buttons, pressing the
trip odometer reset stem will acknowledge the message
and clear it from the DIC 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 are 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 Your
Vehicle is Stuck in Sand, Mud, Ice or Snow on page 4-49.
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. SeeBrake System
Warning Light on page 3-43.
The message could be displayed if the stability
system takes longer than usual to complete its
diagnostic checks due to driving conditions.
3-66

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 LOCK.
10. Set all four tires to the recommended air pressure
level as indicated on the Tire and Loading
Information label.
11. Put the valve caps back on the valve stems
The spare tire does not have a TPM sensor. If you
replace one of the road tires with the spare, the CHECK
TIRE PRESSURE message will be displayed on the
DIC screen. This message should go off once you
re-install the road tire containing the TPM sensor. The
SERVICE TIRE MONITOR message is displayed
when the TPM system is malfunctioning. One or more
missing or inoperable TPM sensors will cause the
service tire monitor message to be displayed. See your
dealer for service.
5-67

*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
HYBRID Hybrid
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
ABS Anti-Lock Brakes
VSES/ECAS Vehicle Stability
Fuses Usage
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
STRTR Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
S/ROOF Sunroof
SEO B2 Off-Road Lamps
4WSVent Solenoid Canister/
Quadrasteer Module Power
RR HVAC Rear Climate Control
AUX PWRAuxiliary Power
Outlet — Console
IGN 1 Ignition Relay
5-111