1998 GMC ENVOY engine

Brakes
Brake Fluid
have your brake system fixed, since a leak means that
sooner or later your brakes won't work well, or won't
work at all.
So, it isn't a good idea to "top off' your brake fluid.
Adding brake fluid won't correct
a leak. If you add fluid
when your linings are worn, then you'll have too much
fluid when you get new brake linings. You should add
(or remove) brake fluid,
as necessary, only when work
is done
on the brake hydraulic system.
Your brake master cylinder reservoir is here.
It is filled
with DOT-3 brake fluid.
There are
only two reasons why the brake fluid level in
the reservoir might go down. The first is that the brake
fluid goes down
to an acceptable level during normal
brake lining wear. When new linings are
put in, the fluid
level goes back up. The other reason
is that fluid is
leaking out
of the brake system. If it is, you should
If you have too much brake fluid, it can spill
on the engine. The fluid will burn
if' the engine
is hot enough.
You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done on the brake
hydraulic system.
Refer to the Maintenance Schedule to determine when to
check your brake fluid. See "Periodic Maintenance
Inspections"
in the Index.
6-27
ProCarManuals.com

NOTICE:
0 Using the wrong fluid can badly damage
brake system parts. For example, just
a few
drops of mineral-based oil, such as engine
oil, in your brake system can damage brake
system parts
so badly that they’ll have to be
replaced. Don’t let someone put in the
wrong kind of fluid.
If you spill brake fluid on your vehicle’s
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid
on your vehicle.
If you do, wash it off
immediately. See “Appearance Care” in
the Index.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that
make a high-pitched warning sound when the brake
pads are worn and new pads are needed. The sound
may come and
go or be heard all the time your vehicle
is moving (except when you are pushim on the brake
pedal firmly).
A CAU‘
The brake wear warning sound means that soon
your brakes won’t work well. That could lead to
an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
NOTICE:
Continuing to drive with worn-out brake pads
could result
in costly brake repair.
6-29
ProCarManuals.com

If you’re not going to drive your vehicle for 25 days
or more, remove the black, negative
(-) cable from
the battery. This will help keep your battery from
running down.
A CAUTION:
Bulb Replacement
Before you replace any bulbs, be sure that all the lamps
are off and the engine isn’t running. See “Replacement
Bulbs”
in the Index.
For any bulb changing procedure not listed
in this
section, contact your GM dealer’s service department.
High Intensity Discharge (HID) Lighting
Batteries have acid that can burn you and gas
that can explode. You can be badly hurt if you
aren’t careful. See “Jump Starting” in the Index
for tips on working around
a battery without
getting hurt.
Contact your dealer to learn how to prepare your vehicle
for longer storage periods.
Also, for your audio system, see “Theft-Deterrent
Feature”
in the Index.
I A CAUTION: I
The low beam High Intensity Discharge lighting
system operates at a very high voltage.
If you try
to service
any of the system components, you
could be injured. Have your dealer or
a qualified
technician service them.
6-31
ProCarManuals.com

Vehicle Identification Number (VIN)
Gl SAMPLE4UXWM072675 Gl
This is the legal identifier for your vehicle. It appears on
a plate in the front corner of the instrument panel, on the
driver’s side. You can see it
if you look through the
windshield from outside your vehicle. The
VIN also
appears on the Vehicle Certification and Service Parts
labels and the certificates
of title and registration.
Engine Identification
The 8th character in your VIN is the engine code. This
code will help you identify your engine, specifications
and replacement parts.
Service Parts Identification Label
You‘ll find this label on the inside of the glove box. It’s
very helpful if you ever need to order parts. On this
label
is:
0 your VIN,
0 the model designation,
0 paint information and
0 a list of all production options and
special equipment.
Be sure that
this label is not removed from the vehicle.
Electrical System
Add-on Electrical Equipment
NOTICE:
Don’t add anything electrical to your vehicle
unless you check with
your dealer first. Some
electrical equipment can damage your vehicle
and the damage wouldn’t be covered by your
warranty. Some add-on electrical equipment
can keep other components from working as
they should.
Your vehicle has an air bag system. Before attempting to
add anything electrical to your vehicle, see “Servicing
Your
Air Bag-Equipped Vehicle” in the Index.
6-54
ProCarManuals.com

FuseKircuit Usage
Breaker
2
3
4
8
9
10
11
12 Cigarette
Lighter, Data
Link Connector
Cruise Control Module and
Switch, Body Control Module,
Heated Seats
Gages, Body Control Module,
Instrument Panel Cluster
Interior Lights
Not Used
Power Outside Mirror, Power
Lock Relay
Courtesy Lamps, Battery
Run-Down Protection
Not Used
Turn Signal
Cluster, Engine Control Module
Parking Lamps, Power Window
Switch, Body Control Module,
Ashtray Lamp
FuseKircuit
Breaker
13
14
15
16
17
18
19
20
21
22
23
24
Usage
Auxiliary Power
Power Locks Motor
4WD Switch, Engine Controls (VCM, PCM, Transmission)
Air Bag
Front Wiper
Not Used
Radio Battery
Amplifier
HVAC
I (Automatic), HVAC
Sensors (Automatic)
Anti-Lock Brakes
Rear Wiper
Radio, Ignition
6-57
ProCarManuals.com

Engine Compartment Fuse Block
The fuse block is under the hood at the driver’s side of
the engine compartment.
Remove the cover
by turning the fastener to the left. To
reinstall the fuse panel cover, push in and
turn the
fastener to
the right.
TRR TRN RTTRN STARTER
rRL BU
Name
TRL TRN
TRR TRN
TRL
BPU
VEH B/U
RT TURN
LT TURN
LT TRN
Usage
Trailer Left Turn
Trailer Right Turn
Trailer
Back-up Lamps
Vehicle Back-up Lamps
Right Turn Signal Front
Left Turn Signal Front
Left Turn Signal Rear
6-58
ProCarManuals.com

Name
RT TRN
RR PRK
TRL PRK
LT HDLP
RT HDLP
LT HI
RT HI
FR PRK
INT BAT
ENG
I
ECM B
ABS
ECM
1
HORN
BTS
I
BIU LP
IGN E
AIC
RAP
OXYSEN
Usage
Right Turn Signal Rear
Right Rear Parking Lamps
Trailer Park Lamps Left Headlamp
Right Headlamp
Left High Beam
Right High Beam
Front Parking Lamps
I/P Fuse Block Feed
Engine SensorsISolenoids, MAP,
CAM. PURGE, VENT
Engine Control Module, Fuel Pump,
Module, Oil Pressure
Anti-Lock Brake System
Engine Control Module Injectors Horn
Brake-Transmission Shift Interlock
Back-up
Lalllps
Engine
Air Conditioning
Retained Accessory Power
Oxygen Sensor
Name
IGN B
DRL
FOG LP
IGN
A
STUD #2
PARKLP
LR PRK
IGN C
HTDSEAT ATC
RRDFOG
HVAC
TRCHMSL
RR W/W
CRANK
LD LEV
HI BEAM
HAZLP
VECHMSL
HTDMIR
STOPLP
TBC
Usage
Column Feed, IGN 2, 3,4
Daytime Running Lamps
Fog Lamps
Starting and Charging IGN
I
Accessory Feeds, Electric Brake
Parking La~nps
Left Rear Parking Lamps Starter Solenoid, Fuel Pump. PRNDL
Heated Seat
Electronic Transfer Case
Rear Defogger
HVAC System
Trailer Center High Mount Stop Light
Rear Window Wiper
Clutch Switch, NSBU Switch
Electronic Load Leveling
HID Headlamps Hazard Lamps
Vehicle Center High
Mount Stop Lamp
Heated Mirror
Stoplamps
Truck Body Computer
6-59
1
ProCarManuals.com

Replacement Bulbs
Lamps
Halogen Headlamps, Composite High Beam
Tail and Stoplamps
Front Sidemarker Lamps
Front Turn Signal Lamps
Turn Signal Lamps
Quantity Number
2 9005 HB3
4 3057
2 194 NA
2 3 157
2 3157 NA
Capacities and Specifications
Type .................................... V6
Firing Order ...................... 1-6-5-4-3-2
Horsepower
................... 190 at 4,400 rpm
Thermostat Specification ........... 195°F (91 “C)
Spark
Plug Gap .......... 0.045 inches (0.114 cm)
Engine Description
............ “VORTEC”
4300
VINCode
.................................W
Wheels and Tires
Wheel Nut Torque ........... 100 lb-ft (140 N-m)
Tire Pressure ...... See the CertificatiodTire label.
See “Loading Your Vehicle” in
the Index.
6-60
ProCarManuals.com