Diagnosesystem für ein Kraftfahrzeug

摘要

The flexibility of a vehicle diagnosis system is increased by providing a memory cartridge 60 for insertion in the diagnostic unit 100, the cartridge including the diagnostic program and communication protocol for the particular vehicle to be tested. So as to allow testing of systems on the vehicle which operate on different supply voltages without changing the cartridge 60, an interface 51 is provided to match the levels of signals passed between the vehicle control unit 2 and the diagnostic unit. This can be done using the circuit of figure 4 to match the level of signals. Alternatively (figure 6), data concerning the supply voltage of the vehicle control system being tested is stored in the ROM 61 of the memory cartridge and this is used to match the signal levels transmitted between the control unit 2 and the diagnostic unit 100. <IMAGE>