A vehicle (100) comprising: an engine (102); a system for starting the engine (102); a fault detection module (120); an electrical power source (110); and a controller (116, 122). The controller (116, 122) is configured to, responsive to the fault detection module (120) detecting a fault occurring with the engine (102): determine a window in which to attempt to start the engine (102); control the electrical power source (110) to provide electrical power to the system for starting the engine (102); and control the system for starting the engine (102) to attempt to start the engine (102) using the supplied electrical power only during the determined window.