A controller for controlling an engine of a vehicle

A controller 125 for controlling an engine 102 of a vehicle 103 is disclosed, along with a control system 101 comprising a controller 125, a vehicle 103 and a method (200 Fig. 2), (500 Fig. 5). The controller comprises control means configured to cause stopping of power generation of the engine during movement of the vehicle in dependence on at least one criterion being met, e.g. vehicle speed or accelerator pedal below threshold or brake pressure above a threshold, and to cause restarting of power generation by the engine, in dependence of at least one input signal indicating a requirement for the engine to restart to provide a required power output. The control means is configured to receive a target engine speed value dependent on a current driveshaft speed and cause the engine to maintain a speed that is no greater than a target engine speed, dependent on the target engine speed value, during a period after receiving the at least one input signal and until a further signal is received indicating a reconnection of the engine to a driveshaft 104; the engine speed may then exceed the target engine speed.