2021 CHEVROLET COLORADO check engine light

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Instruments and Controls 3
Instruments and Controls
Warning Lights, Gauges, and Indicators
Instrument Cluster . . . . . . . . . . . . . . . . . . . . . . . 4
Fuel Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Engine Oil Pressure Gauge . . . . . . . . . . . . . . . 8
Malfunction Indicator Lamp (Check EngineLight) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Wait-to-Start Light . . . . . . . . . . . . . . . . . . . . . . 10
Diesel Exhaust Fluid (DEF) Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power Take-Off Light (Chassis Cab Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Information Displays
Driver Information Center (DIC) . . . . . . . . . 10
Vehicle Personalization
Vehicle Personalization (Van Models) . . . . 11
Vehicle Personalization (PickupModels) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

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
Instruments and Controls 9
Malfunction Indicator Lamp
(Check Engine Light)
This light is part of the vehicle’s emission
control on-board diagnostic system. If this
light is on while the engine is running, a
malfunction has been detected and the
vehicle may require service. The light should
come on to show that it is working when
the ignition is on with the engine not
running. See“Ignition Positions” in the
owner’s manual.
This light may also come on when the
system has detected a problem with the
Diesel Exhaust Fluid (DEF) management
system. See Diesel Exhaust Fluid 022.
Malfunctions are often indicated by the
system before any problem is noticeable.
Being aware of the light and seeking service
promptly when it comes on may prevent
damage.
Caution
If the vehicle is driven continually with
this light on, the emission control system
may not work as well, the fuel economy
may be lower, and the vehicle may not
run smoothly. This could lead to costly
repairs that might not be covered by the
vehicle warranty.
Caution
Modifications to the engine, transmission,
exhaust, intake, or fuel system, or the
use of replacement tires that do not
meet the original tire specifications, can
cause this light to come on. This could
lead to costly repairs not covered by the
vehicle warranty. This could also affect
the vehicle’s ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications 052.
When the light is on, a malfunction has
been detected. Diagnosis and service may be
required.
Poor fuel quality can cause inefficient engine
operation and poor driveability, which may
go away once the engine is warmed up. If this occurs, change the fuel brand. It may
require at least one full tank of the proper
fuel to turn the light off. See
Fuel for Diesel
Engines 025.
If the light remains on, see your dealer.
Emissions Inspection and Maintenance
Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument panel to
the left of the steering wheel. Connecting
devices that are not used to perform an
Emissions Inspection/Maintenance test or to
service the vehicle may affect vehicle
operation. See “Add-On Electrical Equipment”
in the owner’s manual. See your dealer if
assistance is needed.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
10 Instruments and Controls
The vehicle may not pass inspection if:
.The light is on when the engine is
running.
.The light does not come on when the
ignition is on with the engine not
running.
.Critical emission control systems have not
been completely diagnosed. If this
happens, the vehicle would not be ready
for inspection and might require
several days of routine driving before the
system is ready for inspection. This can
happen if the 12-volt battery has recently
been replaced or run down, or if the
vehicle has recently been serviced.
See your dealer if the vehicle will not pass
or cannot be made ready for the test.
Wait-to-Start Light
This light comes on briefly while starting
the engine, as a check to show the light is
working. If the wait-to-start light comes on, the glow
plug system is required and operating. Wait
until the light turns off before starting the
engine. This light may not come on in warm
temperatures.
The fast warm-up glow plug system makes
the wait-to-start light stay on for a shorter
amount of time than most diesel engines.
See
Starting the Diesel Engine 013.
Diesel Exhaust Fluid (DEF)
Warning Light
This light, a Driver Information Center (DIC)
message, and a chime come on when there
is an issue with the Diesel Exhaust Fluid.
If the DEF level has not been corrected, the
light will continue to flash when the vehicle
is started. The vehicle's speed may also be
limited.
Also see Diesel Exhaust Fluid 022.
Power Take-Off Light (Chassis
Cab Only)
Chassis Cab
The vehicle may have a Power Take-Off
(PTO) light. Under normal operating
conditions, the PTO light will remain on
throughout the PTO operating cycle. If all
conditions required to engage PTO have not
been met when enabling PTO, the PTO light
will turn on, then turn off after one second.
See Power Take-Off (PTO) 037.
Information Displays
Driver Information Center (DIC)
The DIC is in the instrument cluster. The DIC
comes on when the ignition is on.
A Duramax diesel vehicle may have the
following additional DIC menu items:

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
20 Driving and Operating
Caution (Continued)
Recommended Fluids and Lubricants
section of this manual are not used. This
damage would not be covered by the
vehicle warranty.
Under certain driving conditions, such as
stop-and-go traffic, the filter cannot clean
itself. A message comes on when the DPF is
dirty and needs to perform a self cleaning.
For the filter to clean itself, the vehicle must
be driven above 50 km/h (30 mph) until the
message goes off. This will take about
30 minutes.
{Warning
During DPF self-cleaning or during
extended idling in P (Park), the exhaust
system and exhaust gases are very hot.
Things that burn could touch hot exhaust
parts under the vehicle and ignite. You or
others could be burned. Do not park,
or idle for an extended period of time,
near or over papers, leaves, dry grass,
or other things that can burn. Keep the (Continued)
Warning (Continued)
exhaust area clear of material that could
ignite or burn. SeeParking over Things
That Burn 019.
Caution
Extended idle should be avoided because
the DPF system is not capable of self
cleaning at idle. During extended idle
operation, monitor the instrument cluster
telltale lights and Driver Information
Center for messages and take appropriate
indicated action. Continued idling with
the warning light/message on could
cause irreversible damage to the DPF
requiring repair and possible replacement
that might not be covered by the vehicle
warranty.
You will also notice a change in the exhaust
sound and engine idle speed. Along with
this, a burning smell and reduction in fuel
economy may be noticed. This is normal.
If you continue to drive with the DPF
warning message on and the exhaust filter
is not cleaned as required, the malfunction
indicator lamp and the ENGINE POWER IS REDUCED message will come on and dealer
service is necessary. See
Malfunction
Indicator Lamp (Check Engine Light) 09.
Vehicles with the DPF have specific fuel and
engine oil requirements. See Fuel for Diesel
Engines 025 and
Engine Oil 055.
Extended idling in P (Park) can cause exhaust
parts and gases to become very hot. Keep
the exhaust area clear of material that could
ignite or burn. See Parking over Things That
Burn 019.
If equipped with Power Take-Off (PTO),
monitor the instrument cluster for lights
related to the DPF.
See Accessories and Modifications 052 for
important information if you are considering
adding accessories or modifying the vehicle.
Manual Regeneration of Diesel
Particulate Filter
This feature is only available on Fleet and
Commercial vehicles.
To verify that the vehicle has this feature,
refer to the Vehicle Service Parts
Identification label (SPID) for RPO code FPF

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
30 Driving and Operating
The system is not harmed by air in the fuel
lines; however, the engine and/or the FOH
may not start until the fuel system is
primed and the air is removed.
Priming the Fuel System
There is an electric priming pump that will
bring fuel to the engine and eliminate air in
the fuel lines. To prime the engine:1. Correct any condition that caused the loss of prime.
2. Turn the ignition on for 30 seconds. Do not start the engine. The fuel pump will
start priming.
3. Turn the ignition off, then back to start, and crank the engine for 15 seconds.
4. If the engine does not start, repeat Steps 2 and 3 until the engine starts.
If the engine does not start after
repeating Steps 2 and 3 three times, turn
the ignition key off for 60 seconds.
5. Repeat the above steps until the engine starts.
6. If the engine starts, but does not run smoothly, increase the engine speed
slightly. 7. If the engine starts and runs but stalls
again, turn the ignition off for
60 seconds.
8. When the engine starts, let it idle for a few minutes and check the filter for any
leaks.
To Prime the Fuel Operated Heater (FOH)
Fuel Lines (Van Models)
See your dealer or qualified technician if the
FOH fuel lines need to be primed.
Running Out of Fuel
If the engine has stalled due to running out
of fuel, try to restart it: 1. If parked on a level surface, add at least 3.8 L (1 gal) of fuel. Up to 18.9 L (5 gal)
may be needed if parked on a slope.
2. Follow the vehicle fuel system priming procedure earlier in this section to
re-prime the system and restart the
engine.
If the check engine light comes on due to
running out of fuel, it may take a few drive
cycles to clear.
On van models only, the Fuel Operated
Heater (FOH) stops automatically when the
fuel tank volume is less than or equal to 10% of the total tank. The FOH fuel lines
will not need to be primed if the vehicle
runs out of fuel.
Fuel Filter Replacement
Van Models
{Warning
Diesel fuel is flammable. It could start a
fire if something ignites it, and people
could be burned. Do not let it get on hot
engine parts, and keep matches or other
ignition sources away.
The fuel filter is on the driver side, inside
the frame rail.
To replace the fuel filter: 1. Drain any water from the filter. See “Removing Water from the Fuel Filter” in
Water in Fuel 027.
Keep the engine off until the procedure
is completed.
2. Apply the parking brake.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 39
3. Press and release the PTO in-cab switchbelow the climate controls in the center
stack. The PTO indicator light will blink
rapidly until the PTO load relay becomes
engaged and will then be on steady. The
engine will advance to the PTO Standby
Speed.
4. Once the PTO Standby Speed is reached, use SET− and +RES on the cruise control
to reach the Set 1 or Set 2 PTO engine
speeds.
The accelerator pedal is disabled and
cannot be used to override the PTO
preset speeds.
Factory Default PTO Engine Speeds
Standby 900 rpm
Set 1 (SET−) 1200 rpm
Set 2 (+RES) 1900 rpm
The first time a vehicle is used for PTO: 1. The PTO Control setting on the GM Service Tool is programmed to Interior
Mode PTO Switch.
2. Check the correct operation of the default PTO preset stationary mode to
observe the three idle up speeds. The
PTO function should be confirmed before any wiring modifications are done or any
reprogramming is attempted. See your
dealer if the default presets are not
functioning properly.
3. The PTO indicator light will not initially reflect the status of the PTO load until
the PTO load relay is wired into the
system. The PTO load relay output is
enabled as a factory default. When the
PTO indicator light is either blinking or
on solid, the PTO relay output will be
activated.
Preset Enable Conditions –Remote
Operation
This requires programming with the GM
Service Tool and remote switch panel
provided by GM Upfitter.
1. Confirm that cruise control is off.
2. Set the parking brake and shift the transmission into P (Park).
3. Turn the engine off. Remove or place the key in the ignition off position. Lock the
vehicle, if desired.
4. Confirm the hood is closed.
5. From outside the vehicle, press and release the Remote PTO Arm switch. 6. Within five seconds, open and close the
Remote PTO Engine Start/Shutdown
switch.
7. The horn will chirp, and then engine starting will be automatically initiated.
The PTO system will then elevate engine
rpm to PTO Standby Speed and engage
the PTO load relay.
8. The Remote PTO Set switch can now be used to accomplish the PTO Set 1 and
Set 2 engine speeds.
The accelerator pedal is disabled when
Remote PTO operation is selected.
Preset Enable Conditions –Remote
Operation In-Cab Enable
This requires programming with the GM
Service Tool and remote switch panel
provided by GM Upfitter.
Starting remote operation in-cab:
1. With the engine running, shift the vehicle into P (Park), release the brake
pedal, and set the parking brake.
2. Confirm that cruise control is off.
3. Confirm the hood is closed.
4. Press and release the in-cab PTO switch.