CHEVROLET C3500 HD 2001 4.G Repair Manual

2-12
Ignition Positions
You can use the key to turn the ignition switch to
five different positions.
ACCESSORY (A): This position lets you use things
like the radio, power windows and the windshield
wipers when the engine is off. Push in the key and turn
it toward you. Your steering wheel will remain locked,
just as it was before you inserted the key.LOCK (B): This position locks your ignition, steering
wheel and transmission. It's a theft
-deterrent feature.
You will only be able to remove your key when the
ignition is turned to LOCK.
OFF (C): This position lets you turn off the engine, but
still turn the steering wheel. It doesn't lock the steering
wheel like LOCK. Use OFF if you must have your
vehicle in motion while the engine is off (for example, if
your vehicle is being pushed).
RUN (D): This is the position for driving.
START (E): This position starts your engine.
CAUTION:
On manual transmission vehicles, turning the key
to LOCK will lock the steering column and result
in a loss of ability to steer the vehicle. This could
cause a collision. If you need to turn the engine
off while the vehicle is moving, turn the key only
to OFF. Don't press the key release button while
the vehicle is moving.

2-13
NOTICE:
If your key seems stuck in LOCK and you can't
turn it, be sure you are using the correct key; if
so, is it all the way in? If it is, then turn the
steering wheel left and right while you turn the
key hard. But turn the key only with your hand.
Using a tool to force it could break the key or the
ignition switch. If none of this works, then your
vehicle needs service.
Key Release Button (Manual Transmission)
The ignition key cannot be
removed from the ignition
of manual transmission
vehicles unless the key
release button is used.To remove the key, turn the key to OFF, press and hold
the button and turn the key to LOCK. Do not hold the
button in while turning the key to OFF.
Starting Your Gasoline Engine
If you have a diesel engine, see ªStarting Your Diesel
Engineº in the Diesel Engine Supplement.
Automatic Transmission
Move your shift lever to PARK (P) or NEUTRAL (N).
Your engine won't start in any other position
-- that's a
safety feature. To restart when you're already moving,
use NEUTRAL (N) only.
NOTICE:
Don't try to shift to PARK (P) if your vehicle is
moving. If you do, you could damage the
transmission. Shift to PARK (P) only when your
vehicle is stopped.

2-14 Manual Transmission
The gear selector should be in NEUTRAL and the
parking brake engaged. Hold the clutch pedal to the
floor and start the engine. Your vehicle won't start if
the clutch pedal is not all the way down
-- that's a
safety feature.
1. With your foot off the accelerator pedal, turn the
ignition key to START. When the engine starts, let
go of the key. The idle speed will go down as your
engine gets warm.
NOTICE:
Holding your key in START for longer than
15 seconds at a time will cause your battery to
be drained much sooner. And the excessive heat
can damage your starter motor. Wait about
15 seconds between each try to help avoid
draining your battery or damaging your starter.
2. If it doesn't start within 10 seconds, push the
accelerator pedal all the way to the floor, while you
hold the ignition key in START. When the engine
starts, let go of the key and let up on the accelerator
pedal. Wait about 15 seconds between each try.When starting your engine in very cold weather
(below 0
F or
-18
C), do this:
1. With your foot off the accelerator pedal, turn the
ignition key to START and hold it there. When the
engine starts, let go of the key. Use the accelerator
pedal to maintain engine speed, if you have to, until
your engine has run for a while.
2. If your engine still won't start (or starts but then stops),
it could be flooded with too much gasoline. Try
pushing your accelerator pedal all the way to the floor
and holding it there as you hold the key in START for
about three seconds. When the engine starts, let go of
the key and accelerator. If the vehicle starts briefly but
then stops again, do the same thing, but this time keep
the pedal down for five or six seconds. This clears the
extra gasoline from the engine.
NOTICE:
Your engine is designed to work with the
electronics in your vehicle. If you add electrical
parts or accessories, you could change the way
the engine operates. Before adding electrical
equipment, check with your dealer. If you don't,
your engine might not perform properly.

2-15
Engine Coolant Heater (If Equipped)
In very cold weather, 0
F
(
-18
C) or colder, the
engine coolant heater can
help. You'll get easier
starting and better fuel
economy during engine
warm
-up. Usually, the
coolant heater should be
plugged in a minimum of
four hours prior to starting
your vehicle.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The engine coolant heater electrical cord is located
on the driver's side of the engine compartment, near
the power steering reservoir.
3. Plug it into a normal, grounded 110
-volt AC outlet.
CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the wrong
kind of extension cord could overheat and cause
a fire. You could be seriously injured. Plug the
cord into a properly grounded three
-prong
11 0
-volt AC outlet. If the cord won't reach, use a
heavy
-duty three-prong extension cord rated for
at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you don't, it could
be damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead of
trying to list everything here, we ask that you contact
your dealer in the area where you'll be parking your
vehicle. The dealer can give you the best advice for that
particular area.

2-16
Automatic Transmission Operation
There are several different positions for your shift lever.
If your vehicle is equipped with an automatic
transmission, it features an electronic shift position
indicator within the instrument panel cluster. This
display must be powered any time the shift lever is
capable of being moved out of PARK (P). This means
that if your key is in OFF, rather than LOCK, there will
be a small current drain on your battery which could
discharge your battery over a period of time. If you have
to leave your key in the ignition in OFF for an extended
period, it is recommended that you disconnect the
battery cable from the battery to prevent discharging
your battery.PARK (P): This position locks your rear wheels. It's the
best position to use when you start your engine because
your vehicle can't move easily.
CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
Don't leave your vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle won't move, even when you're on fairly
level ground, always set your parking brake and
move the shift lever to PARK (P).
See ªShifting Into PARK (P)º in the Index. If
you're pulling a trailer, see ªTowing a Trailerº in
the Index.

2-17
REVERSE (R): Use this gear to back up.
NOTICE:
Shifting to REVERSE (R) while your vehicle is
moving forward could damage your
transmission. Shift to REVERSE (R) only after
your vehicle is stopped.
To rock your vehicle back and forth to get out of snow,
ice or sand without damaging your transmission, see
ªStuck: In Sand, Mud, Ice or Snowº in the Index.
NEUTRAL (N): In this position, your engine doesn't
connect with the wheels. To restart the engine when
you're already moving, use NEUTRAL (N) only. Also,
use NEUTRAL (N) when your vehicle is being towed.
CAUTION:
Shifting out of PARK (P) or NEUTRAL (N) while
your engine is ªracingº (running at high speed) is
dangerous. Unless your foot is firmly on the
brake pedal, your vehicle could move very
rapidly. You could lose control and hit people or
objects. Don't shift out of PARK (P) or
NEUTRAL (N) while your engine is racing.
NOTICE:
Damage to your transmission caused by shifting
out of PARK (P) or NEUTRAL (N) with the
engine racing isn't covered by your warranty.

2-18
AUTOMATIC OVERDRIVE (
): This position is
for normal driving. If you need more power for passing,
and you're:

Going less than about 35 mph (56 km/h), push your
accelerator pedal about halfway down.

Going about 35 mph (56 km/h) or more, push the
accelerator all the way down.
You'll shift down to the next gear and have more power.
AUTOMATIC OVERDRIVE (
) can be used when
towing a trailer, carrying a heavy load or driving on
steep hills. You may want to shift the transmission to
THIRD (3) or, if necessary, a lower gear selection if the
transmission shifts too often.THIRD (3): This position is also used for normal
driving, however it offers more power and lower fuel
economy than AUTOMATIC OVERDRIVE (
).
SECOND (2): This position gives you more power, but
lower fuel economy. You can use SECOND (2) on hills.
It can help control your speed as you go down steep
mountain roads, but then you would also want to use
your brakes off and on.
If you manually select SECOND (2), the transmission
will drive in second gear. You may use this feature
for reducing torque to the rear wheels when you are
trying to start your vehicle from a stop on slippery
road surfaces.

2-19
FIRST (1): This position gives you even more power,
but lower fuel economy than SECOND (2). You can use
it on very steep hills, or in deep snow or mud. If the
selector lever is put in FIRST (1) while the vehicle is
moving forward, the transmission won't shift into first
gear until the vehicle is going slowly enough.
NOTICE:
If your rear wheels can't rotate, don't try to
drive. This might happen if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don't hold
your vehicle there with only the accelerator
pedal. This could overheat and damage the
transmission. Use your brakes or shift into
PARK (P) to hold your vehicle in position on
a hill.
Manual Transmission Operation
5-Speed
Here's how to operate
your transmission.
FIRST (1) is intended only for heavy loads and is not
recommended for normal driving.
During the first 500 miles (805 km) of vehicle use, start
your vehicle moving in FIRST (1). This allows clutch
components to break
-in properly.

2-20
FIRST (1): Press the clutch pedal and shift into
FIRST (1). Then, slowly let up on the clutch pedal as
you press the accelerator pedal. Shift into FIRST (1)
only when the vehicle is below 5 mph (8 km/h). If you
try to shift down into FIRST (1) at excessive vehicle
speeds, the shift lever will not move into the FIRST (1)
position until vehicle speed is reduced.
SECOND (2): Press the clutch pedal and shift into
SECOND (2). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
You can shift into SECOND (2) when you're going less
than 20 mph (32 km/h). If you've come to a complete
stop and it's hard to shift into SECOND (2), put the shift
lever into NEUTRAL and let up on the clutch. Press the
clutch pedal back down. Then shift into SECOND (2).
If you try to downshift into SECOND (2) at excessive
vehicle speeds, the shift lever will not move into the
SECOND (2) position until the vehicle speed is reduced.
THIRD (3): Press the clutch pedal and shift into
THIRD (3). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.FOURTH (4) and FIFTH (5): Shift into the higher
forward gears the same way you do for THIRD (3).
Slowly let up on the clutch pedal as you press the
accelerator pedal.
To stop, let up on the accelerator pedal and press the brake
pedal. Just before the vehicle stops, press the clutch pedal
and the brake pedal, and shift to NEUTRAL.
NEUTRAL (N): Use this position when you start or
idle your engine.
REVERSE (R): To back up, first press down the clutch
pedal. Wait about five seconds for the internal parts to
stop spinning, and then shift into REVERSE (R). Let
up on the clutch pedal slowly while pressing the
accelerator pedal.
NOTICE:
Shift to REVERSE (R) only after your vehicle is
stopped. Shifting to REVERSE (R) while your
vehicle is moving could damage your transmission.
Also, use REVERSE (R), along with the parking brake,
when turning off your engine and parking your vehicle.

2-21 Shift Speeds
CAUTION:
If you skip a gear when you downshift, you could
lose control of your vehicle. You could injure
yourself or others. Don't shift down more than
one gear at a time when you downshift.
If your speed drops below 20 mph (32 km/h), or if the
engine is not running smoothly, you should downshift to
the next lower gear. You may have to downshift two or
more gears to keep the engine running smoothly or for
good performance.Up Shift Light
If you have a manual
transmission, you may have
a SHIFT light. This light
will show you when to shift
to the next higher gear for
best fuel economy.
When this light comes on, you can shift to the next
higher gear if weather, road and traffic conditions let
you. For the best fuel economy, accelerate slowly and
shift when the light comes on.
While you accelerate, it is normal for the light to go on
and off if you quickly change the position of the
accelerator. Ignore the SHIFT light when you downshift.