Page 262 of 386

A CAUTION:
Operating the engine with the air cleaner off can
cause you or others to be burned. The air cleaner
not only cleans the air, it stops flame
if the engine
backfires.
If it isn’t there, and the engine
backfires, you could be burned. Don’t drive with
it
off, and be careful working on the engine with
the
air cleaner off.
NOTICE:
If the air cleaner is off, a backfire can cause a
damaging engine fire. And, dirt can easily get
into your engine, which will damage it. Always
have the air cleaner in place when you’re driving.
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level
is when the engine oil is changed.
Change both the fluid and filter every
15,000 miles
(25 000 km) if the vehicle is mainly driven under one
or more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches
90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of these
conditions, change the fluid and filter every
50,000 miles (83 000 km).
See “Scheduled Maintenance Services’’ in the Index.
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Page 306 of 386

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
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Page 308 of 386

Normal Maintenance Replacement Parts
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing, and are subject
to change. If a part listed in this
manual is not the same as the part used in your vehicle
when it was built, or if you have any questions, please
contact your GMC dealer.
Thermostat
......................... 1255905 1
Oil Filter ............................... PF52
Air Cleaner Filter
...................... A1 163C
PCV Valve
.......................... CV746C
Automatic Transmission Filter Kit
...... 24200796
Spark Plugs
.......................... .41-932
Fuel Filter
............................. GF48 1
Front Windshield Wiper Blade
................ Trico (20 inched50.8 cm)
Backglass Wiper Blade . . Trico (14 inched35.6 cm)
Capacities (Approximate)
Cooling System* ............. 11.7 quarts (1 1.1 L)
Crankcase* ................... 4.5 quarts (4.3 L)
Automatic Transmission
(Drain and Refill)*
........... 5.0 quarts (4.7 L)
Differential Fluid ............................
Front ....................... 2.6 pints (1.2 L)
Rear ........................ 4.0 pints ( 1.9 L)
Fuel Tank ..................... 18 gallons (68 L)
A/C Refrigerant ........... 30 oz. or 2 lbs. (0.9 kg)
of R- 134a
*After refill, the level
must be checked.
6-61
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Page 313 of 386

I I M PORTANT:
KEEP ENGINE OIL
I
AT THE PROPER
LEVEL AND CHANGE AS
RECOMMENDED
Protection
Plan
Introduction
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle
in good working condition, but also helps the
environment. All recornmended maintenance procedures
are inymrtant. Improper vehicle maintenance can even
affect the quality
of the air we breathe. Improper fluid
levels or the wrong tire inflation can increase the level
of emissions fro111 your vehicle. To help protect OLI~
environment. and to keep your vehicle in good
condition, please maintain your vehicle properly.
How This Section is Organized
The remainder of this section is divided into five parts:
“Part A: Scheduled Maintenance Services” shows
what to have done and
how often. Some of these
services can be complex,
so unless you are technically
qualified and have
the necessary equipment, you should
let your dealer‘s service department
or another qualified
service center
do these jobs.
7-2
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Short TripKity Maintenance Schedule I
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 ktn).
See “Owner Checks and Services” and “Periodic
Maintenance Inspections” following.
Footnotes
7 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 ~1sefu1 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 ~ood time to check your brakes is during tire
rotation. See “Brake System Inspection” under ”Periodic
Maintenance Inspections”
in Part C of this schedule.
.:. .:, -,-*,- Drive axle service (see “Recommended Fluids and
Lubricants“ in the Index for proper lubricant to use):
Locking Differential -- Drain fluid and refill at first
engine oil change.
At subsequent oil changes. check
fluid level and add fluid
as needed. If driving in
dusty areas or towing a trailer, drain fluid and refill
every 15,000 miles
(25 000 km).
Standard Differential -- Check fluid level and add
fluid
as needed at every oil change. If driving in
dusty areas or towing a trailer. drain fluid and refill
every
15,000 miles (25 000 km).
More frequent lubrication may be required for
hea\jy-duty
or off-l-oad use.
7-7
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Page 319 of 386

1 Short Trip/City Maintenance Schedule I
3,000 Miles (5 000 km)
Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every
3 months, whichever occurs first).
(See footnote
#.)
Check readfront axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote
**.)
DATE I
MILEAGE
I DATE I
MILEAGE
6,000 Miles (10 000 km)
0 Change engine oil and filter (or every 3 months, whichever occurs first).
0 Lubricate chassis components (or every 3 months, whichever occurs first).
0 Check readfront axle fluid level and add fluid as needed. Check constant
0 Rotate tires. See “Tire Inspection and Rotation” in the Index for proper
An
Emission Control Service.
(See footnote
#.)
velocity joints and axle seals for leaking. (See footnote **.)
rotation pattern and additional information. (See footnote +.)
9,000 Miles (15 000 km)
0 Change engine oil and filter (or every 3 months, whichever occurs first).
0 Lubricate chassis components (or every 3 months, whichever occurs first).
An
Emission
Control Service.
(See footnote
#.)
7-8
I DATE I
MILEAGE ACTUAL I SERVICED BY:
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Page 320 of 386

Short TripKity Maintenance Schedule
0 Check readfront axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote
**.)
12,000 Miles (20 000 km)
0 Change engine oil and filter (or every 3 months, whichever occurs first).
0 Lubricate chassis components (or every 3 months, whichever occurs first).
An Emission Control Service.
(See footnote
#.)
Check readfront axle fluid level and add fluid as needed. Check constant
0 Rotate tires. See “Tire Inspection and Rotation” in the Index for proper
velocity
joints and axle seals for leaking. (See footnote
**.)
rotation pattern and additional information. (See footnote +.)
15,000 Miles (25 000 km)
0 Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.
0 Lubricate chassis components (or every 3 months, whichever occurs first).
0 Inspect air cleaner filter if you are driving in dusty conditions. Replace filter
(See footnote
#.)
if necessary.
An Emission Control Service.
(See footnote?.)
DATE I
I MILEAGE ACTUAL I SERVICEDBY I
I DATE
I MILEAGE ACTUAL I SERVICEDBY: I
(Continued)
7-9
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Page 321 of 386
Short TripKity Maintenance Schedule
15,000 Miles (25 000 kin) (Continued)
0 Check rear/front axle fluid level and add fluid as needed. Check constant
velocity .joints and axle seals for leaking. (See footnote
';"".)
0 Change automatic transmission fluid and filter if the vehicle is mainly driven
under one or more of the.se conditions:
- In heavy city traffic where the outside temperature regularly reaches 90°F
(32°C) or higher.
18,000 Miles (30 000 km)
0 Change engine oil and filter (or every 3 months, whichever occ~lrs first).
0 Lubricate chassis components (or every 3 months, whichever occurs First).
0 Check readfront axle fluid level and add Fluid as needed. Check constant
0 Rotate tires. See "Tire Inspection and Rotation" in the Index for proper
AI? E1nissior? Coutr-01 Service.
(See footnote #.)
velocity joints and axle seals for leaking. (See footnote ';":'.)
rotation pattern and additional information. (See footnote +.)
DATE
7-10
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