2001 GMC SONOMA lock

6-43
3. Remove the bulb.
4. Install a new bulb.
5. Reinstall the lens and tighten the screws.
If equipment such as a cap or camper is installed on
your vehicle, a center high
-mounted stoplamp feed wire
is provided along the driver's side rear frame. This wire
should be used to install a center high
-mounted
stoplamp in the cap or camper.
Taillamps
1. Open the tailgate.
2. Remove the screws from
the lamp assembly near
the tailgate latch.
3. Pull the assembly away from the pickup side panel.
4. Turn the socket counterclockwise to remove it.
Push the tab in while you turn the socket.
5. Pull the bulb out.
6. Push the new bulb into the socket.
7. Put the socket into the assembly and turn the socket
clockwise until it locks in place.
8. Reinstall the assembly. Install and tighten the screws.
9. Close the tailgate.

6-44
Windshield Wiper Blade Replacement
Windshield wiper blades should be inspected at least
twice a year for wear and cracking. See ªWiper Blade
Checkº in the Index for more information.
NOTICE:
Use care when removing or installing a blade
assembly. Accidental bumping can cause the
arm to fall back and strike the windshield.
1. To remove the old wiper blades, lift the wiper arm
until it locks into a vertical position.
A. Blade Assembly
B. Arm Assembly
C. Locking TabD. Blade Pivot
E. Hook Slot
F. Arm Hook
2. Press down on the blade assembly pivot locking tab.
Pull down on the blade assembly to release it from
the wiper arm hook.
3. Remove the insert from the blade assembly. The
insert has two notches at one end that are locked by
bottom claws of the blade assembly. At the notched
end, pull the insert from the blade assembly.

6-45
4. To install the new wiper insert, slide the insert (D),
notched end last, into the end with two blade
claws (A). Slide the insert all the way through the
blade claws at the opposite end (B). The plastic
caps (C) will be forced off as the insert is
fully inserted.
5. Be sure that the notches are locked by the bottom
claws. Make sure that all other claws are properly
locked on both sides of the insert slots.
A. Claw in Notch
B. Correct Installation
C. Incorrect Installation
6. Put the blade assembly pivot in the wiper arm hook.
Pull up until the pivot locking tab locks in the
hook slot.
7. Carefully lower the wiper arm and blade assembly
onto the windshield.

6-65 Instrument Panel Fuse Block
The instrument panel fuse
block is located at the
driver's end of the
instrument panel.
Remove the cover by turning the fastener
counterclockwise. Extra fuses and the fuse extractor are
provided in the cover. To reinstall the fuse panel cover,
push in and turn the fastener clockwise.
Fuse/Circuit
BreakerUsage
A Not Used
B Not Used
1 Not Used
2 Cigarette Lighter,
Data Link Connector

6-66
Fuse/Circuit
BreakerUsage
3 Cruise Control, Body Controls
TBC, Cruise Module,
Cruise Switch
4 Gages, Body Controls TBC,
Instrument Panel Cluster,
B+ Power
5 Parking Lamps, Power Window
Switch, TBC, Ashtray Lamp
6 STR WHL ILLUM
7 Headlamp Switch, Body Controls
TBC, Headlamp Relay
8 Courtesy Lamps, Inadvertent
Power Relay
9 HVAC Control Head
10 Turn Signal
11 Instrument Panel Cluster,
Engine ControlsFuse/Circuit
BreakerUsage
12 Interior Illumination
13 Auxiliary Power
14 Power Locks
15 4WD Switch, Engine Control
(VCM, PCM, Transmission)
16 Supplemental Inflatable Restraint
17 Front Wiper
18 STR WHL RDO IGN
19 Radio Battery
20 AMPF
21 HVAC I, HVAC Control Head,
HVAC Devices
22 Anti
-Lock Brakes
23 Rear Wiper
24 Radio, Ignition

6-67 Engine Compartment Fuse Block
The fuse block is located under the hood on the driver's
side of the engine compartment. See ªEngine
Compartment Overviewº in the Index for more
information on location.
Remove the cover by turning the fastener
counterclockwise. To reinstall the fuse panel cover, push
in and turn the fastener clockwise.
Name Usage
TRL TRN Not Used
TRR TRN Not Used
TRL B/U Not Used
VEH B/U Vehicle Back
-Up Lamps
RT TURN Right Turn Signal Front
LT TURN Left Turn Signal Front
HDLP W/W Not Used

6-68
Name Usage
LT TRN Left Turn Signal Rear
RT TRN Right Turn Signal Rear
RR PRK Right Rear Parking Lamps
TRL PRK Not Used
LT HDLP Left Headlamp
RT HDLP Right Headlamp
FR PRK Front Parking Lamps
INT BAT I/P Fuse Block Feed
ENG I Engine Sensors/Solenoids, MAF,
CAM, PURGE, VENT
ECM B Engine Control Module, Fuel
Pump Module, Oil Pressure
ABS Anti
-Lock Brake System
ECM I Engine Control Module Injectors
BTSI Automatic Transmission Shift
Lock Control System
B/U LP Back
-Up Lamps
A/C Air Conditioning
W/W PMP Not Used
HORN Horn
IGN B Column Feed, IGN 2, 3, 4
RAP Retained Accessory Power
LD LEV Not UsedName Usage
OXYSEN Oxygen Sensor
IGN E Engine
MIR/LKS Mirrors, Door Locks
FOG LP Fog Lamps
IGN A Starting and Charging IGN 1
STUD #2 Accessory Feeds, Electric Brake
PARKLP Parking Lamps
LR PRK Left Rear Parking Lamps
IGN C Starter Solenoid,
Fuel Pump, PRNDL
HTDSEAT Not Used
HVAC HVAC System
TRCHMSL Not Used
RRDFOG Not Used
TBC Truck Body Computer
CRANK Clutch Switch, NSBU Switch
HAZLP Hazard Lamps
VECHMSL Vehicle Center
High
-Mounted Stoplamp
HTDMIR Heated Outside Mirrors
ATC Transfer Case (Four
-Wheel Drive)
STOPLP Stoplamps
RR W/W Not Used

Short Trip/City Scheduled Maintenance
7-8
The services shown in this schedule up to 100,000 miles
(166 000 km) should be performed after 100,000 miles
(166 000 km) at the same intervals. The services shown
at 150,000 miles (240 000 km) should be performed at
the same interval after 150,000 miles (240 000 km).
See ªOwner Checks and Servicesº and ªPeriodic
Maintenance Inspectionsº following.
Footnotes
 The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle's useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.# Lubricate the front suspension, ball joints, steering
linkage, parking brake cable guides, propshaft splines,
universal joints and brake pedal springs.
+ A good time to check your brakes is during tire
rotation. See ªBrake System Inspectionº under
ªPeriodic Maintenance Inspectionsº in Part C of
this schedule.
** Drive axle service. See ªRecommended Fluids and
Lubricantsº in the Index for proper lubricant to use:

Check fluid level and add fluid as needed. If driving
in dusty areas or when towing a trailer, drain fluid
and refill every 15,000 miles (25 000 km).

If your vehicle has a locking differential, drain fluid
and refill at first engine oil change.

More frequent lubrication may be required for
heavy
-duty or off-road use.