Abstract: An on-board computer for a motor vehicle is equipped with a microprocessor which acquires input signals from analog or digital generators and derives display values or display data from them. These display values or display data are displayed on a display system assigned to the on-board computer which preferably is arranged within an instrument cluster of the dashboard of the motor vehicle. For the switching-over or for the free selection of a certain, particularly country-specific, set of programs or data or display values or display data, the on-board computer, which is also used as a diagnostic system for several control units installed into the motor vehicle, is switched to a diagnostic mode and the corresponding set of data is selected by means of the function switch of the on-board computer.

Abstract: An indicating system for an automatic motor vehicle transmission is described which includes second indicating elements in addition to first indicating elements for indicating a preselected driving step. The second indicating elements, particularly during a semi-automatic operating mode of the motor vehicle transmission with a manual preselection of the gear steps, displays an actually shifted gear step. The first and second indicating elements are advantageously arranged in two vertical parallel rows in an indicating instrument of the motor vehicle.

Abstract: A diagnostic system including a display system in a combination instrument of the motor vehicle and a testing unit connected by a stimulating line (L) and a communication line (K) serial bus system to control systems for selectively reading defect reports from the defined storage areas of the control systems and displaying them on the display system. A diagnostic system is started by plugging a diagnostic plug or an external testing unit into a plug device connected with the testing unit or the bus system.