CONTROLLING AN ELECTRIC MACHINE TO SUPPORT DIAGNOSTIC TESTING

Aspects of the present invention relate to a method () and to a control system () for controlling at least one electric machine () of a vehicle () to support diagnostic testing of a vehicle system () comprising an internal combustion engine (), wherein the method () comprises: controlling a torque output () of the at least one electric machine () to allow a vehicle drive torque demand () to be met while the internal combustion engine () is operated within at least one torque threshold () for the diagnostic testing or operated at a torque setpoint () for the diagnostic testing.