Volvo VNL Operator's Manual page 285

280 Brakes
There is also an engine shut-down device
in the EECU that shuts down the engine af-
ter a pre-programmed time in order to save
fuel. This is activated when the yellow
parking brake knob is pulled out. There-
fore, some drivers park and release the
parking brakes using only the red knob to
keep the engine running. It is then easily
overlooked that in a vehicle parked with
both the yellow and red knobs activated,
only the red knob is pushed in by habit.
W5001117
Incorrect Parking or
Driving Position