low oil pressure CHEVROLET COLORADO 2021 Duramax Diesel Supplement

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
8 Instruments and Controls
the tank was half full, but it actually took
a little more or less than half the tank's
capacity to fill the tank.
.The gauge moves a little while turning a
corner or speeding up.
.The gauge does not go back to E (Empty)
when the ignition is turned off.
None of these indicate a problem with the
fuel gauge.
For information on how to fill the fuel tank,
see Filling the Tank 032.
Engine Oil Pressure Gauge
4-Cylinder Pickup Models
See “Oil Pressure” under“Driver Information
Center (DIC)” in the owner’s manual.
Metric Van Models
English Van Models
Caution
Lack of proper engine oil maintenance
can damage the engine. Driving with the
engine oil low can also damage the
engine. The repairs would not be covered
by the vehicle warranty. Check the oil
level as soon as possible. Add oil if
required, but if the oil level is within the
operating range and the oil pressure is
still low, have the vehicle serviced.
Always follow the maintenance schedule
for changing engine oil.
The engine oil pressure gauge reads in kPa
(kilopascals) or psi (pounds per square inch)
when the engine is running. Oil pressure
may vary with engine speed, outside
temperature, and oil viscosity.
If readings are outside the normal operating
range, the low oil pressure message may
display on the Driver Information Center
(DIC), or for vehicles without a DIC the oil
pressure light will come on. If the oil
pressure message or light comes on, check
the oil level immediately. Do not operate
the engine with the oil pressure warning
light on or an ENGINE OIL LOW ADD OIL
message displayed.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
14 Driving and Operating
Observe the wait-to-start light. See
Wait-to-Start Light010. This light may
not come on if the engine is warm.
2. If the wait-to-start light is on, wait until this light goes off. Turn the ignition key
to START, then release the ignition key.
The engine will continue to crank until
the engine starts.
The engine has a fast warm-up glow
plug system. The wait-to-start light will
illuminate for a much shorter time than
most diesel engines, due to the rapid
heating of the glow plug system.
Caution
If the wait-to-start light stays on after
starting the vehicle, the vehicle may not
run properly. Have the vehicle serviced
right away.
3. If the engine does not start after 15 seconds of cranking, turn the ignition
off. Wait one minute for the cranking
motor to cool, then try the same steps
again.
If you are trying to start the engine after
you have run out of fuel, follow the steps in
Running Out of Fuel 030. When the engine is cold, let it run for a few
minutes before driving. This lets oil pressure
build up. The engine will sound louder when
it is cold.
For turbo protection, engine power at
speeds above idle may be limited if the
engine is cold. This protection can last up to
a maximum of 40 seconds at extreme cold
coolant and ambient temperatures.
Cold Weather Starting
Use the recommended engine oil when the
outside temperature drops below freezing.
See
Engine Oil 055. When the outside
temperature drops below –18 °C (0 °F), use
of the engine coolant heater is
recommended.
If you experience longer cranking times,
notice an unusual amount of exhaust smoke,
or are at higher elevations (over 2 135 m or
7,000 ft), you may use the engine coolant
heater. See Engine Heater 017.
See Fuel for Diesel Engines 025 for
information on what fuel to use in cold
weather.
If the Diesel Engine Will Not Start
If the vehicle runs out of fuel, see Running
Out of Fuel 030. If the vehicle is not out of fuel, and the
engine will not start:
Turn the ignition key to ON/RUN. After the
wait-to-start light goes off, turn the ignition
key to START.
If the light does not go off, wait a few
seconds, then try starting the engine again.
See your dealer as soon as possible for a
starting system check.
If the light comes on and then goes off and
you know the batteries are charged, but the
engine still will not start, the vehicle needs
service.
If the light does not come on when the
engine is cold, the vehicle needs service.
If the batteries do not have enough charge
to start the engine, see
“Battery”in the
owner’s manual.
Check that the correct engine oil has been
used and changed at appropriate intervals.
If the wrong oil is used, the engine may be
harder to start.
Be sure you are using the proper fuel for
existing weather conditions. See Fuel for
Diesel Engines 025.
If the engine starts, runs a short time, then
stops, the vehicle needs service.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
44 Driving and Operating
remain at curb idle. A press and release
of +RES on the cruise control will restore
engine rpm to the last PTO set speed. The
PTO system can also be programmed to
return engine rpm to the PTO Standby
Speed setting.
.Press*on the cruise control. The engine
returns to base idle, but the PTO load
relay remains engaged. The PTO indicator
light will blink slowly indicating that a
PTO set speed is still stored in memory.
Activating +RES on the cruise control will
restore engine rpm to the last PTO set
speed.
.Press and release the PTO in-cab switch.
The PTO load relay disengages and the
engine returns to base idle. The PTO
indicator light will turn off, indicating the
PTO load relay is disengaged and the
stored set speed has been cleared from
memory.
Stationary Modes (Preset or Variable) –
Remote Control
To disengage PTO:
.Open the Remote PTO Engine Start/
Shutdown switch. Load relay disengages
and the engine will stop.
.If equipped, press the PTO Emergency
Stop switch. Load relay disengages and
the engine will stop. Refer to the bulletins
in the GM Upfitter Integration website
www.gmupfitter.com for the Power
Take-Off (PTO) operating description and
application guide.
.With the key in the ignition and rotated
to the RUN position, press the brake
pedal. The PTO load relay disengages and
the engine returns to base idle speed. The
operator may drive the vehicle.
Stationary Modes will also disengage if:
.Vehicle movement is detected.
.The parking brake is released.
.The transmission is shifted out of
P (Park).
.The ignition is cycled from RUN to OFF.
.The PTO feedback signal is lost indicating
the load is disengaged if used. See
www.gmupfitter.com.
.Cruise control becomes enabled.
.Timed auto-engine shutdown: This feature
will shut down the engine automatically
after a predefined time. PTO must be
operational for this function to be active.
.Engine shutdown based on critical engine
or PTO system fault conditions: This
feature will shut down the engine when
PTO is operating if a critical engine
condition such as low oil, low oil pressure,
hot engine, hot transmission, low fuel,
or Diesel Particulate Filter regeneration is
detected by the vehicle system. If PTO
operation is continued when critical
engine conditions are present, a horn
chirp warning will occur after 30–
60 seconds. The engine will shut down
two minutes after the horn warning. The
engine can be restarted with the ignition
key or with the Remote PTO engine start
controls. The horn warning and engine
shutdown will again occur if the critical
engine condition is still present.
Resume memory speed is cleared for the
above actions.
When Remote PTO engine starting has been
initialized with the ignition key in the RUN
position, the shift lever will remain locked if
the brake pedal is pressed and a shift from
P (Park) is attempted while the engine is
running and PTO is active (standby mode).
A shift out of P (Park) will not be allowed
until one of the following actions is taken
by the vehicle operator:

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Vehicle Care 55
2.8L 4-Cylinder Engine Van Models
1. Battery
2. Coolant Surge Tank and Pressure Cap
3. Engine Fan (Out of View)
4. Engine Oil Fill Cap
5. Engine Oil Dipstick 6. Engine Air Cleaner/Filter
7. Engine Compartment Fuse Box
8. Power Steering Fluid Reservoir
9. Brake Fluid Reservoir
10. Windshield Washer Fluid Reservoir
Engine Oil
To ensure proper engine performance and
long life, careful attention must be paid to
engine oil. Following these simple, but
important steps will help protect your
investment:

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
60 Vehicle Care
Caution
If the air cleaner/filter is off, dirt can
easily get into the engine, which could
damage it. Always have the air cleaner/
filter in place when driving.
Cooling System
The cooling system allows the engine to
maintain the correct working temperature.
2.8L 4-Cylinder Engine Pickup Models
See“Cooling System” in the owner’s
manual.
2.8L 4-Cylinder Engine Van Models
1. Coolant Surge Tank
2. Coolant Surge Tank Pressure Cap
3. Engine Cooling Fan (Out of View)
{Warning
An underhood electric fan can start up
even when the engine is not running and
can cause injury. Keep hands, clothing,
and tools away from any underhood
electric fan.
{Warning
Do not touch heater or radiator hoses,
or other engine parts. They can be very
hot and can burn you. Do not run the
engine if there is a leak; all coolant could
leak out. That could cause an engine fire
and can burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine coolant
mixture. See Recommended Fluids and
Lubricants 078 and
Maintenance Schedule 073 or
Maintenance Schedule 077. The following explains the cooling system
and how to add coolant when it is low.
If there is a problem with engine
overheating, see
Engine Overheating 062.
A 50/50 mixture of clean, drinkable water
and DEX-COOL coolant will:
.Give freezing protection down to −37 °C
(−34 °F).
.Give boiling protection up to 129 °C
(265 °F).
.Protect against rust and corrosion.
.Help keep the proper engine temperature.
.Let the warning lights and gauges work
as they should.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
the wrong mixture, the engine could get
too hot but there would not be an
overheat warning. The engine could catch
fire and you or others could be burned.