Patent ID: 7783398

Claim:
A program data rewriting system for a control apparatus in a vehicle having a plurality of control apparatuses, said system comprising: a general controller, which is coupled to a network and includes a first recording medium for storing program data as a rewriting subject; and a plurality of controllers, each of which is coupled to the network and includes a second recording medium for storing program data for actuating a function of the control apparatus in a manner capable of being updated; wherein at least one of said controllers includes an environmental data measuring unit which measures at least one of a temperature, a voltage, and a lapsed time after stopping of an engine of the vehicle as environmental data around the controller; a third recording medium, which stores reference data that is compared with the environmental data measured by the environmental data measuring unit to determine whether or not a condition is satisfied; and a comparing unit, which compares the environmental data with the reference data; and wherein said program data stored in said second recording medium is rewritten when said environmental data is within a predetermined range determined by said reference data.