ECU CHEVROLET C/K 2003 Owner's Manual

2-77
CAUTION:
If the right front passenger's air bag is turned off
for a person who isn't in a risk group identified
by the national government, that person won't
have the extra protection of an air bag. In a
crash, the air bag wouldn't be able to inflate and
help protect the person sitting there. Don't turn
off the passenger's air bag unless the person
sitting there is in a risk group. See ªAir Bag Off
Switchº in the Index for more on this, including
important safety information.
CAUTION:
If the air bag readiness light ever comes on when
you have turned off the air bag, it means that
something may be wrong with the air bag system.
The right front passenger's air bag could inflate
even though the switch is off.
If this ever happens, don't let anyone whom the
national government has identified as a member
of a passenger air bag risk group sit in the right
front passenger's position (for example, don't
secure a rear
-facing child restraint in the right
front passenger's seat) until you have your
vehicle serviced.

4-26
Winter DrivingHere are some tips for winter driving:

Be sure the vehicle is in good shape for winter.

You may want to put winter emergency supplies in
your vehicle.
Include an ice scraper, a small brush or broom, a supply
of windshield washer fluid, a rag, some winter outer
clothing, a small shovel, a flashlight, a red cloth and
reflective warning triangles. And, if you will be driving
under severe conditions, include a small bag of sand, a
piece of old carpet or a couple of burlap bags to help
provide traction. Be sure you properly secure these
items in your vehicle.

4-32
If you put things inside your vehicle -- like suitcases,
tools, packages or anything else
-- they will go as fast as
the vehicle goes. If you have to stop or turn quickly, or
if there is a crash, they'll keep going.
CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn, or in
a crash.

Put things in the cargo area of your vehicle.
Try to spread the weight evenly.

Never stack heavier things, like suitcases,
inside the vehicle so that some of them are
above the tops of the seats.

Don't leave an unsecured child restraint in
your vehicle.

When you carry something inside the
vehicle, secure it whenever you can.

Don't leave a seat folded down unless you
need to.
Power Take-Off (PTO) Switch
(If Equipped)
If your vehicle is equipped
for the addition of a PTO,
this factory installed switch
will be located in the
instrument panel
switchbank.
Before using a PTO, refer to the manufacturer's or
installer's instructions.

5-10
Towing Your Vehicle
CAUTION:
To help avoid serious personal injury to you
or others:

Never let passengers ride in a vehicle that is
being towed.

Never tow faster than safe or posted speeds.

Never tow with damaged parts not fully
secured.

Never get under your vehicle after it has
been lifted by the tow truck.

Always secure the vehicle on each side with
separate safety chains when towing it.

Working on air brakes without first using
the release studs to compress the springs
can lead to injury. Never work on the air
brakes chambers without first using the
release studs to compress the brake springs.
CAUTION: (Continued)
CAUTION: (Continued)

When the brake springs are manually
compressed, you will have no brakes.
Release your air
-operated parking brakes
manually only to tow the vehicle. Never
drive the vehicle with the brakes released.
Consult your dealer or a professional towing service if
you need to have your vehicle towed. They can provide
the right equipment and know
-how to tow it without
damage. See ªRoadside Assistanceº in the Index.
Before you do anything, turn on the hazard warning
flashers (if they have not been damaged).
When you call, tell the towing service:

That your vehicle has rear
-wheel drive.

The make, model and year of your vehicle.

Whether you can still move the shift lever.

If there was an accident, what was damaged.
When the towing service arrives, let the tow operator
know that this manual contains towing instructions.
The operator may want to see them.

5-11
Here are specific towing instructions:
Towing Your Vehicle From the Front
(Front Wheels Off the Ground)
Before Towing
Block the rear wheels of the disabled vehicle. On
vehicles with air brakes, release the emergency brake
system by compressing the brake chamber springs
as outlined in this section. (This is to prevent the
possibility of the emergency brake being applied
during towing.)
On vehicles with hydraulic brakes, release the parking
brake fully by moving the lever to the fully
-released
position.
Disconnect the propshaft at the rear axle (forward axle
on tandem axle models). Secure the propshaft to the
frame or crossmember.
Towing the Vehicle with the Front Bumper Removed
1. Remove the front bumper.
2. Connect and lock the lift chains to the front axle,
outside of the spring anchor plates as shown.
A. Spring Anchor Plate
B. Lift Chain
C. Front Axle
3. Place a 6º x 6º x 5' hardwood beam underneath and
slightly behind the front spring shackle brackets.
4. Connect the lift chains to the tow bar and raise the
tow bar until lift chain slack has been taken up and
the hardwood beam is fully seated against the spring
shackle brackets as shown.

5-12
A. Shackle Bracket
B. Tow Bar
C. Lift Chain
D. Hardwood Beam
5. Raise the vehicle to the required height.Towing the Vehicle with the Front Bumper Installed
1. Connect and lock the lift chains to the front axle,
outside of the spring anchor plates as previously
shown.
2. Place a 6º x 6º x 5' hardwood beam underneath and
slightly behind the front spring shackle brackets as
previously shown.
3. Connect the lift chains to the tow bar and take up the
slack in the chains until the tow bar is within 4º of
the front bumper facing. Place a 2º x 12º x 40º
hardwood board with rubber pads against the front
bumper and secure as shown.

5-14
Single Drive Rear Axle
Disconnect the propshaft at the rear axle. Secure the
propshaft to the frame or crossmember.
Tandem Drive Rear Axles
(Forward Axle Off the Ground)
Raise the front of the vehicle until the forward tandem
axle wheels are off the ground. Remove the rearward
propshaft.Tandem Drive Rear Axle (Both Axles on the Ground
Due to Type of Suspension or Attached Load)
Disconnect the propshaft at the forward tandem axle.
Secure the propshaft to the frame or crossmember.
If there is damage or suspected damage to the axle(s),
remove all axle shafts. Cover the hub openings to
prevent the loss of lubricant or entry of dirt or
foreign objects.
After Towing
1. Block the rear wheels and install axle and propshafts.
2. Check for proper phasing of universal joints.
3. Apply the emergency brake system before
disconnecting from the towing vehicle.

5-15 Towing Your Vehicle From the Front
(All Wheels On the Ground)
Your vehicle may be towed on all wheels provided the
steering is working. Remember that the power brakes
and power steering will not have power assist. Vehicles
with air brakes will not have brakes. There must be a
tow bar installed between the towing vehicle and the
disabled vehicle.
Before Towing
Block the wheels of the disabled vehicle. On vehicles
with air brakes, release the emergency brake system by
compressing the brake chamber springs as outlined in
this section. (This is to prevent the possibility of the
emergency brake being applied during towing.)
On vehicles with hydraulic brakes, release the parking
brake fully by moving the lever to the fully
-released
position.
Disconnect the propshaft at the rear axle (forward axle
on tandem axle models). Secure the propshaft to the
frame or crossmember.
If there is damage or suspected damage to the axle(s),
remove the axle shafts. Cover the hub openings to
prevent the loss of lubricant or entry of dirt or
foreign objects.After Towing
1. Block the rear wheels and install axle and propshafts.
2. Check for proper phasing of universal joints.
3. Apply the parking brake system before
disconnecting from the towing vehicle.
4. Check and fill with oil as required.
Towing Your Vehicle From the Rear
Before Towing
Secure the steering wheel to maintain a straight
-ahead
position. Make certain that the front axle is not loaded
above the front axle Gross Axle Weight Rating (GAWR)
as indicated on the vehicle's Gross Vehicle Weight
Rating (GVWR) label. See ªGross Vehicle Weight
Rating (GVWR)º in the index for more information.
After Towing
Block the rear wheels and release the steering. Apply the
parking brake system before disconnecting from the
towing vehicle.
Refer to the transmission shift label for additional
information.

6-81
Fuse Usage
RH PARK LP Right
-hand Parking Lamps
LH PARK LP Left
-hand Parking Lamps
RADIO U Radio
PWR WINDOW Power Windows
BRAKE ISO Brake Warning Lamp
SPARE Spare Fuse
L
-RR TRUCK Left Rear Trailer Wiring
SPARE Spare Fuse
SPARE Spare Fuse
SPARE Spare Fuse
R
-RR TRUCK Right Rear Trailer Wiring
SPARE Spare FuseRelay Usage
BRAKE LAMP C4/C5 Brake Lamps, C6/C7/C8
Tractor/Trailer Wiring
IGN 4 Ignition
MARKER LP Sidemarker and Clearance Lamps
HTD FUEL LB7/LG4 Heated Fuel
AIR HTR LG4 Air Heater
ECU
MAINTAINLG4 Electronic Control Unit
DRL Daytime Running Lamps
CHMSL ISO Center High Mounted Stop Lamp
HTD MIRR Heated Mirrors
R-TRN TLR Right Trailer Turn Signal
L
-TRN TLR Left Trailer Turn Signal
SPARE Spare Relay
SPARE Spare Relay
SPARE Spare Relay

7-17
(10) = Check clutch pedal for free travel. Press pedal
by hand until resistance is felt. Free travel should be
maintained at 1.5 to 2 inches (38 to 51 mm) measured
at the clutch pedal pad. Make checks at 1,000 miles
(1 600 km) and then at every 7,500 mile (12 000 km)
interval thereafter.
(11) = Inspect rear axle air shift motor for fluid leaks.
Remove plug to check fluid level. Inspect air lines and
hoses for proper hook
-up, binding, leaks, etc. Inspect at
3,000 miles (5 000 km) and 22,500 miles (36 000 km)
and then every 22,500 miles (36 000 km) thereafter.
(12) = Chassis Lubrication Service: Lubricate all grease
fittings in front suspension, front axle and steering
linkage. DO NOT lubricate kingpin bushings with air
pressure equipment; instead, use a hand grease gun to
ensure complete purge and eliminate sealer cap
distortion. Lubricate transmission and shift linkage,
hood latches and hood hinges, parking brake lever pivot,
clevis pins and linkage, disc brake caliper rails, clutch
linkage and release bearing (if equipped), bearing pads,
propshaft universal joints, brake camshaft bracket, slack
adjusters, pedal shaft, clutch cross shaft and clutch pedal
springs. Lubricate suspension, axle and steering linkage
more often when operating under dusty or muddy
conditions and in excessive off
-road use.(13) = Check steering system:

Look for damaged, loose or missing parts. Also look
for parts showing signs of wear or lack of lubrication.
Replace parts as needed. Also check steering gear
mounting bolts, pitman arm nut, gear housing upper
cover and side cover attaching bolts, steering column
mounting bolts and cardan joint clamp bolts; tighten
if necessary. (See service manual.)

Inspect power steering hoses, tubes and fittings for
leaks. Hoses and lines must not be twisted, kinked or
tightly bent. Make sure clips, clamps, supporting
tubes and hoses are in place and properly secured.

Check steering gear for leakage around pitman shaft
and housing. If leakage is evident (lubricant oozing
out, not just oily film), leak should be corrected
immediately.
(14) = Check front and rear suspension. Look for
damaged, loose or missing parts or parts showing signs
of wear or lack of lubrication. Replace parts as needed.