•

Exhaust Fluid Empty Refill Now

•

Speed Limited to 6 km/h (4 mph)

The messages are alternately displayed every five seconds on the DIC. Both messages remain on the DIC until acknowledged by the driver; however, the
Speed Limited to 6 km/h (4 mph) Max, message remains locked on the DIC.
The DEF Indicator in the instrument panel flashes continuously. The vehicle remains in Warning Level 9 until the DEF reservoir is refilled.
Vehicle speed is limited to 6 km/h (4 mph) maximum.
If the vehicle speed has been limited and DEF has been added, it may take up to 30 seconds after engine start with the vehicle stopped for the EXHAUST
FLUID EMPTY message to clear. If the vehicle is driven prior to the DIC message clearing, the vehicle speed will still be limited. If the DIC message clears while
driving, the vehicle must be completely stopped to remove the speed limitation. For this condition, it is highly recommended to allow the message to clear prior to
driving the vehicle.
If DEF is added under freezing conditions, additional time may be required to remove speed limitations.

Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)
A supply of clean, fresh diesel exhaust fluid (DEF) is critical for optimum selective catalyst reduction (SCR) efficiency. Selective catalyst reduction (SCR)
efficiency is determined by monitoring the nitrogen oxide (NOx) sensors located upstream and downstream of the SCR. This vehicle provides the driver with an
elaborate series of prompts and warnings that are initiated when the engine control module (ECM) detects a drop in the SCR NOx reduction efficiency
suggesting a diluted or contaminated DEF supply.
When contaminated or diluted DEF is suspected, the ECM initiates the DEF Quality warning process. Once initiated, DEF quality warnings grow increasingly
more serious as the vehicle continues to be driven. The vehicle’s current DEF quality warning status is displayed on the scan tool. When a drop in SCR
efficiency is detected, the normally OFF Reductant Field Quality Warning Indicator Command will display Warning Level 1 through Warning Level 5 depending
on the number of miles driven, the number of ignition cycles, and if a refueling event was detected. The series of DEF Quality Warnings alert the driver that DEF
system service is urgently needed.

Warning Level 1
Warning Level 1 is triggered when the ECM first detects the SCR efficiency is below a calibrated value. The driver information center (DIC) displays the
following messages:

•

Exhaust Fluid Quality Poor

•

See Owner’s Manual Now

•

89 km/h (55 mph) Max Speed on Restart

The messages remain on the DIC until acknowledged by the driver. The DEF Indicator in the instrument panel is illuminated

Warning Level 2
Warning Level 2 is triggered when the distance driven since receiving the first DEF poor quality message exceeds approximately 805 km/h (500 mi). The driver
will hear four chimes on entering Warning Level 2. The DIC displays the following messages:

•

Exhaust Fluid Quality Poor

•

See Owner’s Manual Now

•

89 km/h (55 mph) Max Speed on Restart

The messages alternate every five seconds until acknowledged by the driver; however, the 89 km/h (55 mph) Max Speed on Restart, remains displayed on the
DIC. The DEF Indicator in the instrument panel is illuminated.

Warning Level 3
Warning level 2 automatically advances to warning level 3 at the next ignition cycle. The driver will hear four chimes on entering warning level 3. The series of
chimes is repeated three times during each ignition cycle. The DIC displays the following messages:

•

Exhaust Fluid Quality Poor

•

See Owner’s Manual Now

•

89 km/h (55 mph) Max Speed on Restart

The messages alternate every 5 seconds until acknowledged by the driver; however, the Speed Limited to 89 km/h (55 mph), remains displayed on the DIC.
The DEF Indicator in the instrument panel flashes continuously.
Vehicle speed is limited to 89 km/h (55 mph).
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Warning Level 4
Warning Level 4 is triggered when the distance driven since receiving the first DEF Quality Warning message exceeds approximately 1,609 km (1,000 mi). The
driver will hear four chimes on entering Warning Level 4. The series of four chimes will repeat three times during each ignition cycle. The DIC displays the
following messages:

•

Exhaust Fluid Quality Poor

•

See Owner’s Manual Now

•

89 km/h (55 mph) Max Speed on Restart

•

6 km/h (4 mph) Max Speed Next Fuel Fill

The messages alternate every five seconds until acknowledged by the driver; however, the Speed Limited to 89 km/h (55 mph), and 6 km/h (4 mph) Max Speed
Next Fuel Fill, remain alternately displayed on the DIC. The DEF Indicator in the instrument panel flashes continuously.
Vehicle speed is limited to 89 km/h (55 mph).

Warning Level 5
Warning Level 5 is triggered when the distance traveled is greater than 1,609 km (1,000 mi) and the ECM detects a fuel fill event. The driver will hear four
chimes on entering Warning Level 4. The series of four chimes will repeat every three minutes. The DIC displays the following messages:

•

Exhaust Fluid Quality Poor

•

See Owner’s Manual Now

•

6 km/h (4 mph) Max Speed Next Fuel Fill

The messages alternate every five seconds until acknowledged by the driver; however, the Speed Limited to 6 km/h (4 mph), remains displayed on the DIC.
The DEF Indicator in the instrument panel flashes continuously.
Vehicle speed is limited to 6 km/h (4 mph) maximum.

Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)
The reductant system supplies the selective catalyst reduction (SCR) stage of the vehicle’s exhaust aftertreatment system with the diesel exhaust fluid (DEF)
required to reduce exhaust oxides of nitrogen (NOx) levels. The engine control module (ECM) continuously monitors the performance of the reductant system
during operation.
When the conditions associated with an attempt to disable reductant system operation are detected, the ECM activates the anti-tampering feature and presents
the driver with a series of prompts and warnings.
Once initiated, anti-tampering warnings grow increasingly more serious as the vehicle continues to be driven. The vehicle’s current warning status is displayed
on the scan tool. When tampering is suspected, the normally OFF Reductant System Malfunction Warning Indicator Command will display Warning Level 1
through Warning Level 5 depending on the number of miles driven, the number of ignition cycles, and if a refueling event was detected. The series antitampering warnings alert the driver that reductant system service is urgently needed.

Warning Level 1
Warning level 1 is triggered when the ECM first detects an abnormal value on a reductant system circuit. The driver information center (DIC) displays the
following messages:

•

Service Exhaust Fluid System

•

See Owner’s Manual Now

The messages remain on the DIC until acknowledged by the driver. The DEF Indicator in the instrument panel is illuminated.

Warning Level 2
Warning level 2 is triggered when the distance driven since receiving the first Service Exhaust Fluid System, message exceeds approximately 805 km (500 mi).
The driver will hear four chimes on entering Warning Level 2. The DIC displays the following messages:

•

Service Exhaust Fluid System

•

See Owner’s Manual Now

•

89 km/h (55 mph) Max Speed on Restart

The messages alternate every five seconds until acknowledged by the driver; however, the 89 km/h (55 mph) Max Speed on Restart, remains displayed on the
DIC. The DEF Indicator in the instrument panel is illuminated.
The system will advance from Warning Level 2 to either Warning Level 3 or Warning Level 4 depending on whether the ECM detects that additional fuel was
added. The system advances to Warning Level 3 at the next ignition cycle if no fueling event was detected or to Warning Level 4 if additional fuel was added

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during the current ignition cycle.

Warning Level 3
Warning Level 2 automatically advances to Warning Level 3 at the next ignition cycle. The driver will hear four chimes on entering Warning Level 3. The series
of four chimes is repeated three times during each successive ignition cycle. The DIC displays the following messages:

•

Service Exhaust Fluid System

•

See Owner’s Manual Now

•

89 km/h (55 mph) Max Speed on Restart

The messages alternate every five seconds until acknowledged by the driver; however, the Speed Limited to 89 km/h (55 mph), remains displayed on the DIC.
The DEF Indicator in the instrument panel flashes continuously.
Vehicle speed is limited to 89 km/h (55 mph).

Warning Level 4
Warning Level 4 is triggered when the distance driven since receiving the first warning message exceeds 3,218 km (2,000 mi). The driver will hear four chimes
on entering Warning Level 4. The series of four chimes will repeat three times during each successive ignition cycle. The DIC displays the following messages:

•

Service Exhaust Fluid System

•

See Owner’s Manual Now

•

89 km/h (55 mph) Max Speed on Restart

•

6 km/h (4 mph) Max Speed Next Fuel Fill

The messages alternate every five seconds until acknowledged by the driver; however, the Speed Limited to 89 km/h (55 mph), and 6 km/h (4 mph) Max Speed
Next Fuel Fill, remain alternately displayed on the DIC. The DEF Indicator in the instrument panel flashes continuously.
Vehicle speed is limited to 89 km/h (55 mph).

Warning Level 5
Warning Level 4 automatically advances to Warning Level 5 when ECM detects a fuel fill event. The driver will hear four chimes on entering Warning Level 5.
The series of four chimes will repeat every three minutes until the vehicle is serviced. The DIC displays the following messages:

•

Service Exhaust Fluid System

•

See Owners Manual Now

•

6 km/h (4 mph) Max Speed Next Fuel Fill

The messages alternate every five seconds until acknowledged by the driver; however, the Speed Limited to 6 km/h (4 mph), remains displayed on the DIC.
The DEF Indicator in the instrument panel flashes continuously.
Vehicle speed is limited to 6 km/h (4 mph) maximum.

Q&A
Q. Where can you purchase DEF?
A. DEF is available at GM dealerships and most major truck stop chains. GM DEF is available in a variety of package sizes to service both individual
consumers and fleets, including 3.78 and 9.46 L (1 and 2.5 gal) jugs, 208 L (55 gal) drums and 1249 L (330 gal) totes.
The GM part numbers are:

•

1 gallon (P/N 19286291) (U.S.), 88862660 (Canada)

•

2.5 gallon (P/N 19286292) (U.S.), 88863524 (Canada)

•

55 gallon Drum (P/N 88863494) (U.S.), 88863496 (Canada)

•

330 gallon Tote (P/N 88863495) (U.S.); tote not available in Canada

If purchasing DEF outside of a dealership, you must use API-certified or ISO 22241 labeled DEF. If you need assistance locating DEF, the U.S. Department of
Energy has a DEF locator on its website that is regularly updated. You can visit the website at: afdc.energy.gov/afdc/locator/def/.
Q. Will DEF freeze?
A. Yes, DEF will freeze—at approximately −11°C (12ºF)
Q. Does DEF expand when it freezes and if so, how does it impact the tank?
A. Yes, DEF expands when it freezes. The vehicle’s DEF tank and all DEF packaging is designed to accommodate any expansion that may result from being
frozen if the tank is not overfilled
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Q. Can a freeze-point improver be added to the DEF to keep it from freezing?
A. No, doing so would alter the DEF mixture balance potentially triggering an “EXHAUST FLUID QUALITY POOR” DIC message.
Q. Does DEF have a limited shelf life?
A. DEF has a limited shelf life related to temperature (see chart below). It is best stored out of direct sunlight between -11°C (12ºF) and 30°C (86ºF).
Constant Ambient Storage Temperature C/F

Shelf Life (Months)

< 10 / 50

36

< 25 (a) /77

18

< 30 / 86

12

< 35 / 95

6

> 35/95

(b)

Note: The main factors taken into account to define the shelf life in this table are the ambient storage temperature and the initial alkalinity of
AUS 32. The difference in evaporation between vented and non-vented storage containers is an additional factor.
(a) To prevent decomposition of AUS 32, prolonged transportation or storage above 25°C (77°F) should be avoided.
(b) Significant loss of shelf life: Check each batch before use.
Q. Will DEF containers have a date stamp?
A. Yes, each container should be dated.
Q. What will happen if some other type of liquid is poured into the DEF system?
A. DEF is the only fluid approved and recommended by General Motors. Using a product not recommended by GM will trigger a DIC warning message and may
damage the SCR system and void the warranty coverage (see DEF quality portion of this brochure). Refer to SI diagnostics for additional information.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may
occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools,
safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that
your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

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