Method for generating a technical document of functional specifications of a control unit of a vehicle to be programmed while the control unit is programmed, the vehicle comprising a device, the control unit being suitable to receive and process first CAN messages and generate and send second CAN messages, the method comprising the following steps: - association of a first CAN message contained in a list of messages to a relative first label, this CAN message containing at least one parameter and/or one value of a physical magnitude of said device, - association of a filter in model-based format contained in a list of filters to a relative second label, said filter comprising at least one input and/or one second operating parameter, - association of a technical description draft, as a pre-set template, of said filter to said filter, wherein a first generic name is associated to said at least one input and/or one second operating parameter of said filter, - association of each value relating to a physical magnitude or operating parameter of said device to a third label, - a visualization of said first, second and third labels, - a first selection of a first CAN message from said list of messages, suitable for being received and processed by the control unit, - a second selection of one or more filters in model-based format from said list of filters, - an assignment of said first parameter or physical magnitude value contained in said first CAN message to said input and/or second operating parameter of the filter, - replacement of said generic name of said pre-set template, with said third label, - generation of a technical document formatted according to a standard scheme and referring to said messages and filters contained in the respective database accompanied by their respective documentation. - association of a first CAN message contained in a list of messages to a relative first label, this CAN message containing at least one parameter and/or one value of a physical magnitude of said device, - association of a filter in model-based format contained in a list of filters to a relative second label, said filter comprising at least one input and/or one second operating parameter, - association of a technical description draft, as a pre-set template, of said filter to said filter, wherein a first generic name is associated to said at least one input and/or one second operating parameter of said filter, - association of each value relating to a physical magnitude or operating parameter of said device to a third label, - a visualization of said first, second and third labels, - a first selection of a first CAN message from said list of messages, suitable for being received and processed by the control unit, - a second selection of one or more filters in model-based format from said list of filters, - an assignment of said first parameter or physical magnitude value contained in said first CAN message to said input and/or second operating parameter of the filter, - replacement of said generic name of said pre-set template, with said third label, - generation of a technical document formatted according to a standard scheme and referring to said messages and filters contained in the respective database accompanied by their respective documentation.