Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 225
When Increasing Vehicle Speed
When the cruise control resume
switch is operated, the speed
increases while the switch is held.
After the speed is increased to the
desired vehicle speed, and the
switch is released, the speed is set
at the increased vehicle speed.
If you want to increase the speed
quickly, press the accelerator pedal
and accelerate to the desired
vehicle speed. Then, operate the
cruise control set switch.When Increasing Vehicle Speed
Slightly
If the cruise control resume switch is
operated and released immediately,
the set vehicle speed increases
1.6 km/h (1 MPH) per operation.
This operation can be performed 10
times consecutively.
When Decreasing Vehicle Speed
When the cruise control set switch
is operated, the speed decreases
while the switch is held.
After the speed is decreased to the
desired vehicle speed, and the
switch is released, the speed is setat the decreased vehicle speed.
If you want to decrease the speed
quickly, press the brake pedal to
cancel cruise control and decelerate
to the desired vehicle speed. Then,
operate the cruise control set
switch.
When Decreasing Vehicle Speed
Slightly
If the cruise control set switch is
operated and released immediately,
the set vehicle speed decreases
1.6 km/h (1 MPH) per operation.
This operation can be performed 10
times consecutively.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
226 Driving and Operating
When Canceling Cruise Control
Press the cruise control main switch
again to turn the cruise control
system off. The cruise control main
indicator light will go out.
The cruise control set speed is
canceled in the following cases:
.When the brake pedal is
pressed.
. When the selector lever is
shifted to the N position.
. When cruising speed is
approximately 27 km/h (17
MPH). * .
When the vehicle speed
decreases more than 20% below
your set speed.
. When the cruise control main
switch is turned off. *
. When the engine control switch
is turned to the LOCK position. *
. When trouble develops in the
system. *
Memory speed is eliminated. *
When you do not use the cruise
control, be sure to place the cruise
control main switch into off.
When you place the engine control
switch into ACC, place the cruise
control main switch into off, then
reset the cruise control if you want
to use the cruise control again.
Using Cruise Control on Hills
How well your cruise control will
work on hills depends upon your
speed, load and the steepness of
the hills. When going up steep hills,
you may want to step on the
accelerator pedal to maintain your
speed. When going downhill, you may have to brake or shift to a lower
gear to keep your speed down. Of
course, applying the brake takes
you out of cruise control. Many
drivers find this to be too much
trouble and do not use cruise
control on steep hills.
When Returning to Cruise Control
Driving
If you have canceled cruise control
under the following conditions, you
can return to the cruise control
driving condition before cancellation
when you operate and release the
cruise control resume switch. The
moment the resume switch is
released, the cruise set indicator
light comes on.
.
When pressing the brake pedal.
. When the selector lever is
shifted to the N position.
When the vehicle speed decreases
to 40 km/h (25 MPH) or less, it is
not possible to return to the cruise
control driving. You must reset the
cruise control.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
232 Driving and Operating
from your dealer, service stations,
parts stores and other automotive
places. See your authorized dealer
for advice on using biocides in your
area and for recommendations on
which biocides you should use.
Smoke Suppressants
Because of extensive testing of
treated fuel versus untreated fuel,
the use of a smoke suppressant
additive is not recommended
because of the greater possibility of
stuck rings and guttered valves,
resulting from excessive ash
deposits.
Water Separator
The purpose of the water separator
is to separate any water from the
fuel that may have formed in the
fuel tank due to condensation.
The water separator is located on
the bottom of the fuel filter.
Caution
Remaining water that is not
discharged from the water
separator could freeze and
damage the vehicle.
If the warning light comes on
while the engine is in operation,
promptly drain the water from the
water separator (fuel filter).
Continuing to drive with the light
remaining on could damage the
fuel injection system. If this
happens, have the vehicle
checked and serviced by the
nearest dealer.
Draining Water from the Fuel
Filter
Clean off any fuel that has adhered
to the vehicle body.
Starting the engine immediately
after draining the water from the fuel
filter requires a little more time than
usual. If the engine does not start in
10 seconds, wait for a while and try
again.Fuel will be mixed in the drained
water. Dispose of it in a method
conforming to the regulatory
requirements in your state.
If the water separator (fuel filter)
requires frequent draining, have the
fuel system inspected at your
dealer.Pre Fuel Filter (Chassis-side)
1. Attach a plastic hose to the drain plug (2) on the bottom of
the chassis-side fuel filter and
put the other end of the hose in
a container placed beneath the
filter.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 233
2. Loosen the drain plug andmove the priming pump (1) up
and down by hand between
10 and 20 times.
3. Fully tighten the drain plug (2) and move the priming pump (1)
several times.
Fuel Filter (Engine-side)
1. Attach a plastic hose to the drain plug (2) on the bottom of
the engine-side fuel filter (1)
and put the other end of the
hose in a container placed
beneath the filter.
2. Loosen the drain plug andmove the priming pump up and
down by hand between 10 and
20 times.
3. Fully tighten the drain plug and move the priming pump several
times.
4. Test run the engine and check that there are no fuel leaks
from the drain plug of the
engine-side fuel filter. Also
check that the water separator
(fuel filter) warning light
stays off.
Running Out of Fuel
When the Fuel Tank is Empty
When the fuel tank is empty, air will
enter the fuel system, so refueling
alone will not be enough to restart
the engine. Use the following
methods to bleed the fuel system.
Bleeding the Fuel System
Steps for Refueling
1. Follow the directions in "Parking Brake Lever" under
Parking Brake 0220.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
234 Driving and Operating
2. Select the correct fuel (See"Diesel Fuel Requirement and
Fuel System"). Follow any
posted safety rules. Stand to
the side, never above or
opposite the filler opening.
3. Check that the fuel cap is tight, and see to it that engine oil,
engine coolant in the reservoir,
and washer fluid, etc. are at
proper levels. Then do the
Driver Daily Checklist.
See Owner Checks and Services
0 340.
Driving your vehicle until the fuel
tank is empty may activate the
check engine malfunction indicator
light. You do not need to have your
vehicle checked. After refueling,
perform the following:
. Bleed the fuel system.
. Start, turn off and restart the
engine three or four times.
. The check engine malfunction
indicator light will be cancelled. Before Starting the Engine
1. The priming pump (1) is
located on the outboard side of
the left frame rail, in front of the
batteries. Place a container
beneath the air bleed plug (2)
to receive fuel, and then fully
loosen the plug.
2. Attach a clear hose onto the air bleed plug, direct the clear
hose into a catch pan.
3. Pump the priming pump (1) up/ down for 65 times to get most
of the air bubbles out. Note fuel
was drawn into the filter bowl at
around 40 - 50 times. 4. Fully retighten the air bleed
plug (2) and wipe off any fuel
that may have adhered to the
plug or surrounding area.
5. Continue to operate the pump for 50 times.
6. Start the engine.
7. If the engine does not start, repeat steps 5 and 6 as
necessary until it does start.
After Starting the Engine 1. Without pressing the accelerator pedal, start the
engine.
2. After the engine has started, allow it to idle for about
5 seconds.
3. Fully press the accelerator pedal and increase the engine
speed to the maximum speed
for 10 seconds. (Repeat this
operation several times.)
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
246 Vehicle Care
and the oil should be changed
regularly according to the
Maintenance Schedule.
The engine oil performs the
following important functions:
.It prevents engine parts from
becoming worn.
. It cools engine parts.
. It cleans engine parts.
. It seals the combustion
chambers and prevents rust.
Replace the engine oil at regular
intervals.
When particulate matter (PM) has
accumulated to a preset level in the
diesel particulate filter (DPF), the
filter is automatically regenerated
through combustion. To make this
regeneration (combustion) possible,
a small amount of fuel is injected
into the engine combustion chamber
after firing. This causes fuel to
gradually become mixed with the
engine oil, and the engine oil level
may rise beyond the original level.
This does not indicate a malfunction
of the engine.Access to the Engine
Single Cab Model
Access to the engine oil dipstick is
located on the engine left side after
tilting the cab. See Cab Tilting
0 243.
Crew Cab Model
The engine oil dipstick is under the
engine inspection sub cover located
beneath the driver's seat.
Checking the Engine Oil Level
Press the engine oil level check
switch. If engine oil level is low the
red oil pressure warning light will
turn on. If the engine oil level is
above the "OK", the green oil level
indicator will turn on.
The oil level varies while the engine
is running, right after it is stopped,
and on sloping ground. When
checking the oil level, be sure the
vehicle is on level ground while the
engine is cool.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 253
.Dipstick H (HOT) —
Transmission fluid
temperature Approx. 70 -
80 °C (158 - 176 °F).
. The “C (COLD)” range on
the dipstick is a guide used
by your dealer for
specialized equipment used
to replace or service the
automatic transmission
fluid. When performing your
own inspections, always
use the “H (HOT)” range
after warming up the
vehicle.
The fluid must be hot to
ensure an accurate check.
The fluid level rises as
temperature increases.
6. If the fluid level is too low, add the specified fluid through the
dipstick guide tube. Also, check
whether there are no fluid
leaks.
7. Insert the dipstick securely into position.{Warning
Be extremely careful not to burn
yourself when checking the oil
level if the engine temperature is
high. Protect yourself with
gloves etc.
You and others could be seriously
injured.
Discarded parts, oil, grease and
fluids could have an adverse effect
on the environment. It is difficult to
dispose of these, so have your
dealer handle all checks and
replacements.
Engine Air Cleaner/Filter
Air Cleaner
Using a clogged air cleaner element
not only reduces engine output but
also causes increased fuel
consumption and an increased DPF
regeneration frequency. Be sure to use a genuine air cleaner
element. If a different air cleaner
element is used, it may cause the
sensor to output a wrong signal.
See
Maintenance Schedule 0327.
Air Cleaner Indicator Light
When the air cleaner indicator light
comes on, check the air cleaner
element. If the air cleaner element is
clogged, replace the air cleaner
element.
See Vehicle Messages 086.
See Maintenance Schedule 0327.
Engine Coolant
Protection of Engine Against
Overcooling
Overcooling of the engine not only
accelerates wear of the vital engine
parts but also hurts fuel economy.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 259
Engine Overheating
When the Engine Overheats
The engine cooling system may
overheat if the engine coolant level
is too low, if there is a sudden loss
of engine coolant (such as radiator
hose failure), or if other problems
occur. It may also temporarily
overheat during severe operating
conditions such as:
.Climbing a long hill on a hot day.
. Stopping after high-speed
driving.
. Idling for long periods in traffic.
If engine power drops and the
needle on the engine coolant
temperature gauge goes up above
the upper limit of the safety zone
and enters the "H" zone, the engine
is overheating. The engine overheat
warning light will come on and the
warning buzzer will sound. Either
steam or boiling engine coolant will
squirt out of the radiator. The
vehicle will also have an “OVERHEAT”
message displayed. Take the
following corrective actions
immediately.{Warning
To help avoid being burned:
Do not tilt the cab or open the
engine access cover if you see or
hear steam or engine coolant
escaping from the engine
compartment. Wait until no steam
or engine coolant can be seen or
heard before tilting the cab or
opening the engine cover.
Do not remove the radiator cap or
engine coolant reserve tank cap if
the engine coolant in the tank is
boiling. Also do not remove the
radiator cap while the engine and
radiator are still hot. Scalding fluid
and steam can be blown out
under pressure if either cap is
taken off too soon.
You and others could be seriously
injured. If Steam Is Coming from the
Engine Compartment
{Warning
If the engine coolant temperature
gauge shows an overheat
condition or you have other
reasons to suspect the engine
may be overheating, continued
operation of the engine (other
than as described here) even for
a short period of time may cause
a fire and the result in personal
injury and severe vehicle
damage. Take immediate action
as outlined.
You and others could be seriously
injured.
If you see or hear escaping steam
or have any other reason to suspect
there is a serious overheat
condition, stop and park the vehicle
as soon as it is safe to do so, turn
on the hazard warning flasher and
then turn off the engine immediately
and safely exit the vehicle.