Chevrolet Low Cab Forward 4500 2019 Series Owner's Manual page 181

180 Driving and Operating
At the same time the cruise set
indicator light comes on.
Accelerating during Cruise
Control Driving
If you want to accelerate temporarily
to pass another vehicle while driving
using the cruise control, press the
accelerator pedal. When you
release the accelerator pedal, the
speed returns to the original set
vehicle speed.
When Increasing Vehicle Speed
When the cruise control resume
switch is operated, the speed
increases while the switch is held.
After the speed is increased to the
desired vehicle speed, and the
switch is released, the speed is set
at the increased vehicle speed.
If you want to increase the speed
quickly, press the accelerator pedal
and accelerate to the desired
vehicle speed. Then, operate the
cruise control set switch.
When Increasing Vehicle Speed
Slightly
If the cruise control resume switch is
operated and released immediately,
the set vehicle speed increases
1.6 km/h (1 MPH) per operation.
This operation can be performed 10
times consecutively.
When Decreasing Vehicle Speed
To decrease the speed after it is
initially set, operate the cruise
control set switch and hold it.