2002 GMC ENVOY lock

6-57 Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses and circuit
breakers. This greatly reduces the chance of fires caused
by electrical problems.
Look at the silver
-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the identical size
and rating.
If you ever have a problem on the road and don't have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of your vehicle that
you can get along without
-- like the radio or cigarette
lighter
-- and use its fuse, if it is the correct amperage.
Replace it as soon as you can.
Air Conditioning Refrigerant Capacity
If you do your own service work, you'll need the proper
service manual. See ªDoing Your Own Service Workº in
the Index for additional information. It is recommended
that service work on your air conditioning system be
performed by a qualified technician.Engine Compartment Fuse Block
The fuse block is located under the hood in the engine
compartment on the driver's side of the vehicle. 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.

6-59
Mini Fuses Usage
1 ECAS
2 Passenger's Side
High
-Beam Headlamp
3 Passenger's Side
Low
-Beam Headlamp
4 Back
-Up Trailer Lamps
5 Driver's Side
High
-Beam Headlamp
6 Driver's Side
Low
-Beam Headlamp
7 WASH
8ATC
9 Windshield Wipers
10 Powertrain Control Module B
11 Fog Lamps
12 ST/LP
13 Cigarette Lighter
14 COILSMini Fuses Usage
15 RIDE
16 TBD
-- Ignition 1
17 Crank
18 Air Bag
19 ELEK Brake
20 Cooling Fan
21 Horn
22 Ignition E
23 ETC
24 Instrument Panel Cluster,
Driver Information Center
25 Automatic Shift Lock
Control System
26 ENG 1
27 Back
-Up
28 Powertrain Control Module 1
29 Oxygen Sensor

6-60
Mini Fuses Usage
30 Air Conditioning
31 TBC
50 Passenger's Side Trailer TRN
51 Driver's Side Trailer TRN
52 Hazard Flashers
J
-Case Fuses Usage
32 Trailer
33 Anti
-Lock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Ignition B
Micro Relays Usage
37 Headlamp Washer
38 Rear Window Washer
39 Fog LampsMicro Relays Usage
40 Horn
41 Fuel Pump
42 Windshield Wipers/Washer
43 High
-Beam Headlamp
44 Air Conditioning
Solid State
RelaysUsage
45 Cooling Fan
46 HDM
Mini Relay Usage
47 Starter
Miscellaneous Usage
48 Instrument Panel Battery
49 Fuse Puller

6-61
Rear Underseat Fuse Block
The rear underseat fuse block is located under the rear
seat on the driver's side of the vehicle.

6-62
Fuse Usage
01 Right Door Control Module
02 Left Door Control Module
03 LGM 2
04 TBC 3
05 Rear Fog Lamps
06 LGM/DSM
07 TBC 2
08 Power Seats
09 Blank
10 DDM
11 AMP
12 PDM
13 Rear Climate Controls
14 Left Rear Parking Lamps
15 Auxiliary Power 2
16 VEH CHMSLFuse Usage
17 Right Rear Parking Lamps
18 LOCK
19 Blank
20 Sunroof
21 LOCKS
23 Blank
24 UNLOCK
25 Blank
26 Blank
27 OH Battery/OnStar

System
29 Rainsense Wipers
30 Parking Lamps
31 TBC 4CC
32 TBC 5
33 Front Wipers
34 VEH STOP

7-17
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. See ªRecommended Fluids and Lubricantsº
in the Index.
Automatic Transmission Check
Check the transmission fluid level; add if needed.
See ªAutomatic Transmission Fluidº in the Index.
A fluid loss may indicate a problem. Check the system
and repair if needed.At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part D.
Body Lubrication Service
Lubricate all hood latch assembly, secondary latch,
pivots, spring anchor, release pawl, rear compartment
hinges, outer liftgate handle pivot points, rear door
detent link, roller mechanism, liftgate handle pivot
points, latch bolt, fuel door hinge, cargo door hinge,
locks and folding seat hardware. Part D tells you what to
use. More frequent lubrication may be required when
exposed to a corrosive environment.

7-18
Starter Switch Check
CAUTION:
When you are doing this check, the vehicle could
move suddenly. If it does, you or others could be
injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. See ªParking Brakeº in the Index if necessary.
Do not use the accelerator pedal, and be ready to turn
off the engine immediately if it starts.
3. Try to start the engine in each gear. The starter
should work only in PARK (P) or NEUTRAL (N).
If the starter works in any other position, your
vehicle needs service.Automatic Transmission Shift Lock Control
System Check
CAUTION:
When you are doing this check, the vehicle could
move suddenly. If it does, you or others could be
injured. Follow the steps below.
1. Before you start, be sure you have enough
room around the vehicle. It should be parked
on a level surface.
2. Firmly apply the parking brake. See ªParking Brakeº
in the Index if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the key to the RUN
position, but don't start the engine. Without applying
the regular brake, try to move the shift lever out of
PARK (P) with normal effort. If the shift lever
moves out of PARK (P), your vehicle needs service.

7-19
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.

The key should turn to LOCK only when the shift
lever is in PARK (P).

The key should come out only in LOCK.
Parking Brake and Automatic Transmission
PARK (P) Mechanism Check
CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in case
it begins to roll. Be ready to apply the regular
brake at once should the vehicle begin to move.
Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake,
set the parking brake.

To check the parking brake's holding ability: With
the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.

To check the PARK (P) mechanism's holding ability:
With the engine running, shift to PARK (P).
Then release the parking brake followed by the
regular brake.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.