Chevrolet Low Cab Forward 6.7L 2022 Owner's Manual page 160

Stage Stage 1
Restriction None
Stage 1 : When incorrect DEF or an SCR
system malfunction is detected, the DEF
indicator light and the engine check warning
light will come on as shown in the
Incorrect DEF/SCR System Malfunction
Warnings table.
Stage 2 : If driving is continued for
approximately another 1 hour, engine torque
will be reduced by 25%.
Stage 3 : If driving is continued for
approximately another 3 hours, the DEF
indicator light will begin blinking and the
engine check warning light will remain on.
Engine torque will be reduced by an
additional 1% per minute up to a maximum
reduction of 40% of specified torque.
Incorrect DEF/SCR System Malfunction Warnings (cont'd)
Stage 2
- Engine torque is reduced
by 25%
Stage 4 : After reaching Stage 3, if any of
the following triggers is met, engine torque
will remain reduced by 40% and the vehicle
speed will be limited to 8 km/h (5 MPH):
The engine is restarted
The engine idles for over 1 hour
The fuel tank is refilled
See Handling of DEF and Adding DEF
earlier in this section. See Diesel Exhaust
Fluid (DEF) Warning Light 0 57, Engine
Shutdown Warning Light 0 57, and
Malfunction Indicator Lamp (Check Engine
Light) 0 51.
Driving and Operating
Stage 3 Stage 4
Engine torque remains
- Engine torque is reduced
reduced by 40% of
by an additional 1% per
specified torque
minute up to a maximum
reduction of 40% of
Vehicle speed is limited to
specified torque
8 km/h (5 MPH)
When the Diesel Exhaust Fluid (DEF) Tank is
Empty
If the DEF tank is empty and warning and
indicator lights are on, you must follow
below procedure to cancel the vehicle
restriction:
1. Turn the engine control switch to the
LOCK or ACC position, and add DEF.
2. After adding DEF, turn the engine control
switch to ON position.
3. Wait until buzzer stops, warnings and
indicators are turned off.
It may take a while until the warning
lights and indicators turn off and the
buzzer stops after turning the engine
control switch to the "ON" position.
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