Chevrolet Low Cab Forward 6.7L 2022 Owner's Manual page 158

Stage
Refill DEF as soon as
Required action
possible *1
Remarks:
*1 See Adding DEF earlier in this section.
Stage 1 : When the remaining level of DEF
becomes excessively low the DEF gauge will
change color from green to amber. In
addition, the DEF indicator light will come
on as shown in the table.
Stage 2 : If driving is continued without
adding DEF, engine torque will be reduced
by 25%.
Stage 3 : If driving is continued after the
DEF tank is empty, the DEF indicator light
will begin blinking and the engine check
warning light will come on. Engine torque
will be reduced by an additional 1% per
minute up to a maximum reduction of 40%
of specified torque.
DEF Tank Level is Low/Empty (cont'd)
Stage 1 Stage 2
Refill DEF immediately *1
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 Adding DEF in Cold Weather and
When the Diesel Exhaust Fluid (DEF) Tank is
Empty earlier in this section. See Diesel
Exhaust Fluid (DEF) Warning Light 0 57.
Incorrect Diesel Exhaust Fluid (DEF)/SCR
System Malfunction Warnings
The SCR system continuously monitors
emissions reduction performance and SCR
system malfunction. When a malfunction or
incorrect fluid (such as water or low
concentrated DEF, etc.) is detected, the SCR
system will turn on warning and indicator
lights to encourage you to have the
condition corrected.
Driving and Operating
Stage 3
Refill DEF immediately *1 Refill DEF immediately *1
In the case of incorrect fluid or if an SCR
system malfunction is detected, continuing
to drive for too long after these lights come
on may eventually result in a severe vehicle
speed limitation. The following is a
summary of the warning lights, indicator
lights and restrictions. When these warning
and indicator lights come on, promptly have
the vehicle inspected and serviced at your
dealer.
157
Stage 4