2001 GMC SIERRA headlamp

6-44 Headlamps
1. Remove the two pins on the top of the headlamp
assembly. To remove the pins, turn the outer pin
outward and pull it straight up. To remove the inner
pin, turn it inward and pull it straight up.
A. Low-Beam Headlamp
B. High
-Beam Headlamp
2. Pull the headlamp lens assembly out.
3. Unplug the electrical connector.
4. Turn the old bulb counterclockwise and remove it
from the headlamp lens assembly.
5. Put the new bulb into the lens assembly and turn it
clockwise until it is tight. Use care not to touch the
bulb with your fingers or hands.
6. Plug in the electrical connector.
7. Put the headlamp lens assembly back into the
vehicle. Install and tighten the two pins.

6-45 Front Turn Signal, Sidemarker and
Daytime Running Lamps
A. Sidemarker Lamp
B. Retainer Clip
C. Front Turn Signal Lamp
D. Daytime Running Lamp1. Remove the headlamp lens assembly as
mentioned previously.
2. Press the retainer clip, located behind the turn
signal housing, towards the outside of the vehicle.
3. Pull the turn signal housing out from the vehicle.
4. Press the locking release lever, turn the bulb socket
counterclockwise and remove it from the turn signal
lens housing.
5. Remove the old bulb from the bulb socket.
6. Put the new bulb into the bulb socket. Use care
not to touch the bulb with your fingers or hands.
7. Put the bulb socket into the turn signal housing
and turn it clockwise until it locks.
8. Put the turn signal housing back onto the vehicle
placing the hook and posts on the inner side into the
alignment holes first and then the outer side into the
retainer bracket until you hear a click.
9. Put the headlamp lens assembly back into the vehicle.

6-60
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted the
same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new GM original
equipment parts. This way, you will be sure to have the
right wheel, wheel bolts and wheel nuts for your vehicle.
CAUTION:
Using the wrong replacement wheels, wheel bolts
or wheel nuts on your vehicle can be dangerous.
It could affect the braking and handling of your
vehicle, make your tires lose air and make you
lose control. You could have a collision in which
you or others could be injured. Always use
the correct wheel, wheel bolts and wheel nuts
for replacement.
NOTICE:
The wrong wheel can also cause problems with
bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper
height, vehicle ground clearance and tire or tire
chain clearance to the body and chassis.
Whenever a wheel, wheel bolt or wheel nut is replaced
on a dual wheel setup, check the wheel nut torque after
100, 1,000 and 6,000 miles (160, 1 600 and 10 000 km)
of driving. For proper torque, see ªWheel Nut Torqueº
in the Index.
See ªChanging a Flat Tireº in the Index for
more information.

6-78
Name Usage
ETC Electronic Throttle Control
IGN E A/C Compressor Relay, Rear
Window Defogger, Daytime
Running Lamps, A.I.R. System
B/U LP Backup Lamps, Automatic
Transmission Shift Lock
Control System
ATC Automatic Transfer Case
RR DEFOG Rear Window Defogger,
Heated Mirrors (Relay)
RR PRK Right Rear Parking Lamps
ECM B PCM
F/PMP Fuel Pump (Relay)
O2 A Oxygen Sensors
FUEL HT Fuel Heater, Glow Plug and
Intake Heater Controls
O2 B Oxygen Sensors
LR PRK Left Rear Parking Lamps
RR DEFOG Rear Window Defogger,
Heated MirrorsName Usage
HDLP Headlamps (Relay)
TRL PRK Parking Lamps Trailer Wiring
RT HDLP Right Headlamps
DRL Daytime Running Lamps (Relay)
HTD MIR Heated Mirrors
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

6-79
Name Usage
CIGAR Cigarette Lighter,
Auxiliary Power Outlets
RT TURN Right Turn Signals
BTSI Automatic Transmission Shift
Lock Control System
LT TURN Left Turn Signals
FR PRK Front Parking Lamps,
Sidemarker Lamps
W/W PMP Windshield Washer Pump
HORN Horn (Relay)
IGN C Ignition Switch, Fuel Pump,
PRND321 Display, Crank
RDO AMP Not Used
HAZ LP Exterior Lamps, Hazard Lamps
EXP LPS Not Used
HORN Horn
CTSY LP Interior Lamps
RR WPR Not Used
TBC Body Control Module, Remote
Keyless Entry, HeadlampsReplacement Bulbs
Low-Beam Headlamps2 9006
High
-Beam Headlamps2 9005
Daytime Running Lamps (DRL) 2 3157KX
Front Marker Lamp 2 194
Front Parking and Turn Lamp 2 3157 A
Rear Marker Lamp,
Taillamp and Stop Lamp2 3157
Taillamp and Stop Lamp** 2 1157
Rear Turn Lamp 2 3157
Rear Turn Lamp ** 2 1156
Back
-up Lamp2 3157
Back
-up Lamp **2 1156
Center High
-Mounted Stoplamp2 912
Cargo Lamp 2 912
* For replacement bulbs not listed here, please consult
your dealer.
** Chassis Cab Models