2003 CHEVROLET C/K Owners Manual

6-83
Underhood Fuse Block
When a circuit goes out, the problem could be in either
the primary or secondary underhood fuse blocks. These
blocks uses blade
-type fuses.
Both underhood
fuse blocks are
located in the engine
compartment, on the
passenger's side of
the vehicle.
Primary Underhood
Fuse BlockTo access the fuse blocks, gently squeeze both sides of
the cover to unlatch the tabs at the top. Then, unsnap
both attachments at the bottom and remove the cover.
Be sure to replace fuses with fuses of the same rating.
Do not use fuses of higher amperage than those
indicated on the fuse block.

6-84
Primary Underhood Fuse Block
Relay Usage
NOTE 1 LG4 Powertrain Control Valve,
L18/LB7 Fuel Pump,
LG5 Heated Fuel
IGN B Ignition
STARTER StarterRelay Usage
HORN Horn
IGN A Ignition
PTO Power Take
-Off
REVERSE Reverse
NEUTRAL
STARTNeutral Start
Fuse Usage
RR DEFOG Rear Defog
ENG 1 Engine 1
ENG 3 Engine 3
PCM
-B Powertrain Control Module
BLANK Empty
ENG 4 Engine 4
ENG 2 Engine 2
HTD FUEL Heated Fuel
BLANK Empty
BLANK Empty

6-85
Fuse Usage
BLANK Empty
A/C COMP Air Conditioning Compressor
ABS 1 Anti
-Lock Brake System 1
ABS 2 Anti
-Lock Brake System 2
ABS 3 Anti
-Lock Brake System 3
ENGINE Engine
E/A PUMP Electronic/Automatic Pump
HORN Horn
NOTE 2 L18/LB7 Fuel, LG4 Powertrain
Control Valve, LG5 Electronic
Control Module
BLANK Empty
STUD A Spare
STUD B Spare
Secondary Underhood Fuse Block
Fuse Usage
IGN 1 Ignition 1
IGN 4 Ignition 4
IGN 3 Ignition 3
BATT/HAZ Battery/Hazard Warning Flashers
HEADLAMP Headlamps
LIGHTING Interior/Exterior Lamps
HVAC Comfort Control System
NOTE C4/C5 Electric Brake,
C6/C7/C8 Brake Lamps

6-86
Replacement Bulbs
It is recommended that you use an ACDelco
type bulb whenever you need to replace one.
If you need a bulb replaced, contact your dealer.
Capacities and Specifications
Engine Specifications
Engine RPO LG5 L18 LG4 LB7
Engine Type 7.2L L6 8.1L V8 7.8L L6 6.6L V8
Fuel System HEUI SPFI Common Rail Common Rail
Firing Order
1
-5-3-6-2-41-8-7-2-6-5-4-31-5-3-6-2-41-2-7-8-4-5-6-3

6-87 Cooling System Capacity
The following approximate capacities are given in
English and metric conversions.
Please refer to ªRecommended Fluids and Lubricantsº
in the Index for more information.
C4/C5 Models Quarts (Liters). . . . . . . . . . . . . . . . .
8.1L with manual transmission 30.1 (28.5). . . . . . . .
8.1L with automatic transmission 29.8 (28.2). . . . . .
6.6L with manual transmission 27.6 (26.1). . . . . . . .
6.6L with automatic transmission 27.3 (25.8). . . . . .
C6/C7/C8 Models Quarts (Liters). . . . . . . . . . . . . .
8.1L with manual transmission 33.3 (31.5). . . . . . . .
8.1L with manual transmission,
air conditioning and increased
cooling 34.9 (33.0). . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1L with automatic transmission 32.5 (30.8). . . . . .
7.8L 200
-230 hp engine with
manual transmission 31.6 (29.9). . . . . . . . . . . . . . . .
7.8L 200
-230 hp engine with manual
transmission, air conditioning and
increased cooling 35.3 (33.4). . . . . . . . . . . . . . . . . . . C6/C7/C8 Models Quarts (Liters). . . . . . . . . . . . . .
7.8L 200
-215 hp engine with
automatic transmission 33.7 (31.9). . . . . . . . . . . . . .
7.2L 175
-230 hp engine with
manual transmission 29.3 (27.7). . . . . . . . . . . . . . . .
7.2L 175
-230 hp engine with
manual transmission, air conditioning
and increased cooling 33.0 (31.2). . . . . . . . . . . . . . .
7.2L 175
-210 hp engine with
automatic transmission 31.4 (29.7). . . . . . . . . . . . . .
7.8L 250
-275 hp engine with
manual transmission 34.9 (33.0). . . . . . . . . . . . . . . .
7.8L 250
-275 hp engine with
manual transmission, air conditioning
and increased cooling 35.4 (33.5). . . . . . . . . . . . . . .
7.8L 230
-275 hp engine with automatic
transmission 33.3 (31.5). . . . . . . . . . . . . . . . . . . . . .
7.2L 250
-300 hp engine with manual
transmission 32.8 (31.0). . . . . . . . . . . . . . . . . . . . . .
7.2L 250
-300 hp engine with manual
transmission, air conditioning and
increased cooling 33.3 (31.5). . . . . . . . . . . . . . . . . . .
7.2L 250
-300 hp engine with automatic
transmission 31.2 (29.5). . . . . . . . . . . . . . . . . . . . . .

6-88 Engine Oil with Filter Capacity
Engine Quarts (Liters)
7.2L** 30.0 (28.4)*
8.1L** 6.5 (6.1)
7.8L** 23.8 (22.5 )
6.6L** 14.6 (13.8)
*Additional oil is required with auxiliary oil filter
systems. Make sure to add enough extra oil to fill the
auxiliary oil filter system. For vehicles equipped with
the LUBERFINER 750
-C, add 14 quarts (13.25 L).
** Check fill level on the oil indicator after initial fill to
make sure it is actually full. Oil level may vary
depending on vehicle option content.
Fuel Tank Capacity
C4/C5 Models Gallons (Liters). . . . . . . . . . . . . . . . .
Standard* 41 (155.2). . . . . . . . . . . . . . . . . . . . . . . .
Optional 40 (151.4). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 60 (227.1). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 80 (302.8). . . . . . . . . . . . . . . . . . . . . . . . . .
C6/C7/C8 Models Gallons (Liters). . . . . . . . . . . . . .
Standard 50 (189.2). . . . . . . . . . . . . . . . . . . . . . . . .
Optional 35 (132.4). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 50 (189.2). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional
70 (264.8) . . . . . . . . . . . . . . . . . . . . . . . .
Optional75 (283.8) . . . . . . . . . . . . . . . . . . . . . . . .
Optional& 100 (378.5). . . . . . . . . . . . . . . . . . . . . . .
* One 25
-gallon (94.6 L) tank and one 16-gallon
(60.6 L) tank

Two 35
-gallon (132.4 L) tanks
One 25
-gallon (94.6 L) tank and One 50-gallon
(189.2 L) tank
&Two 50
-gallon (189.2 L) tanks

6-89 Transmission Capacity
For manual transmissions, the correct oil level is to the
bottom of the fluid fill plug opening. The oil capacity
will vary, due to the angle of the transmission, with the
vehicle. For automatic transmissions, see the Allison
Automatic Transmission Operator's Manual for oil
check and maintenance information.
Manual Transmission Pints (Liters). . . . . . . . . . . .
ZF S6
-650 12.7 (6.0). . . . . . . . . . . . . . . . . . . . . . . . .
RT6609 12.5 (5.9). . . . . . . . . . . . . . . . . . . . . . . . . . .
RT8709B 25.1 (11.8). . . . . . . . . . . . . . . . . . . . . . . . .
FS4205A, FS4205B, FS4205C 11.1 (5.3). . . . . . . . .
FS5205A, FS5205C 11.6 (5.5). . . . . . . . . . . . . . . . .
FS5406 18.4 (8.7). . . . . . . . . . . . . . . . . . . . . . . . . . .
FS6305A, FS6305B 18.4 (8.7). . . . . . . . . . . . . . . . .
FS6406 18.4 (8.7). . . . . . . . . . . . . . . . . . . . . . . . . . .
FS8406 18.5 (8.8). . . . . . . . . . . . . . . . . . . . . . . . . . .
RT8908LL 29.1 (13.8). . . . . . . . . . . . . . . . . . . . . . . . Automatic Transmission Pints (Liters). . . . . . . . . .
MD 3060 P 52.0 (24.6)*. . . . . . . . . . . . . . . . . . . . .
MD 3560 P 52.0 (24.6)*. . . . . . . . . . . . . . . . . . . . .
1000 Series 16.0 (8.9)*. . . . . . . . . . . . . . . . . . . . . .
2000 Series 35.0 (13.5)*. . . . . . . . . . . . . . . . . . . . .
2200 Series 35.0 (13.5)*. . . . . . . . . . . . . . . . . . . . .
2400 Series 35.0 (13.5)*. . . . . . . . . . . . . . . . . . . . .
*Add two pints (one liter) when changing spin-on or
remote filter.

6-90 Rear Axle Lubricant Capacity
Single Speed Axle Pints (Liters). . . . . . . . . . . . . . . .
80 10.0 (4.7). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S135 26.0 (12.3). . . . . . . . . . . . . . . . . . . . . . . . . . . .
19060S 31.0 (14.7). . . . . . . . . . . . . . . . . . . . . . . . . .
21060D 31.0 (14.7). . . . . . . . . . . . . . . . . . . . . . . . . .
21060S 31.0 (14.7). . . . . . . . . . . . . . . . . . . . . . . . . .
S150 28.0 (13.0). . . . . . . . . . . . . . . . . . . . . . . . . . . .
23090S 40.0 (19.0). . . . . . . . . . . . . . . . . . . . . . . . . .
23105S 56.0 (26.5). . . . . . . . . . . . . . . . . . . . . . . . . .
26105S 54.0 (25.5). . . . . . . . . . . . . . . . . . . . . . . . . .
Tw o
-Speed Axle Pints (Liters). . . . . . . . . . . . . . . . .
19060T 38.0 (18.0). . . . . . . . . . . . . . . . . . . . . . . . . .
21060T 38.0 (18.0). . . . . . . . . . . . . . . . . . . . . . . . . .
23082T 40.0 (19.0). . . . . . . . . . . . . . . . . . . . . . . . . .
26080T 44.0 (20.8). . . . . . . . . . . . . . . . . . . . . . . . . .
Tandem Axles Pints (Liters). . . . . . . . . . . . . . . . . . .
DS344 (front) 32.0 (15.1). . . . . . . . . . . . . . . . . . . . .
RS344 (rear) 31.0 (14.7). . . . . . . . . . . . . . . . . . . . . .
DSH44 (front) 32.0 (15.1). . . . . . . . . . . . . . . . . . . . .
RSH44 (rear) 31.0 (14.7). . . . . . . . . . . . . . . . . . . . . .
DS404, DS404P (front) 32.0 (15.1). . . . . . . . . . . . . .
RS404 (rear) 31.0 (14.7). . . . . . . . . . . . . . . . . . . . . .
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.
Air Conditioning Refrigerant
R134a 2.1 lbs. (1.0 kg). . . . . . . . . . . . . . . . . . . . . . .
Use Refrigerant Oil, R143a Systems
Normal Maintenance
Replacement Parts
Allison Transmission External Filters
See the Allison Transmission Operator's Manual in your
vehicle for external filter part numbers and information.
Air Compressor Filter
Air Compressor Part Number
Bendix Tu
-Flo
550 (13.2 CFM)2467368