Method for transmitting program codes to a memory of a control device, particularly for motor vehicles

In order to transmit program codes to a program memory of a control device, particularly for motor vehicles, all memory cells of the program memory are first cleared and written preferably with an invalid program code (illegal Opcode). Valid program codes are compressed according to a lossless data compression method and particularly the Huffman coding, transmitted to the control device, decompressed there accordingly, and written into the program memory of the control device. The value for the invalid program code is saved in the control device as the standard value (default) or is transmitted at maximum once from the programming device to the control device. By means of said measures, the data volume to be transmitted and consequently the time for the transmission of the program code is significantly reduced.