m4f is an incorrect start, either driving direction is not in neutral, or accelerator pedal and or brake pedal is not in rest-position before (seat switch) and keyswitch are activated.

If the truck is active, also the seat switch must be closed before accelerator and/or direction switch is closed, if not> truck will give incorrect start (as the name implies).
Same goes for when the truck is in SRO Static Return Off, all inputs must be neutral.