System and method for reprogramming vehicle computers

A method of reprogramming a non-volatile memory of an on-board vehicle computer circuit with new computer program code, comprising the steps of:

• establishing a common communication link between said on-board vehicle computer circuit and an off-board controller having said new computer program code;
• transmitting a sequence of command signals from said off-board controller to said on-board vehicle computer circuit over said common communication link for enabling said non-volatile memory to receive said new computer program code;
• processing said sequence of command signals by said on-board vehicle computer circuit and transmitting a sequence of responsive signals to said off-board controller over said common communication link, at least one of said responsive signals including an identification code;
• processing said responsive signals by said off-board controller in accordance with a predetermined transfer protocol which checks said identification code to determine if said new computer program code should be transmitted to said on-board vehicle computer circuit;
• and
• transmitting said new computer program code from said off-board controller to said on-board vehicle computer circuit over said common communication link when permitted under said predetermined transfer protocol, and storing said new computer program code in said non-volatile memory.