VEHICLE ELECTRONIC CONTROL SYSTEM, SELF-RETENTION POWER EXECUTION CONTROL METHOD AND COMPUTER PROGRAM PRODUCT

In a vehicle electronic control system, a vehicle master device includes a vehicle power determination unit that is configured to determine a vehicle power is on, a rewrite-in-progress determination unit that is configured to determine whether rewriting of a program is in progress, a first self-retention power determination unit that is configured to determine whether it is necessary to self-retain power in the vehicle slave device when the vehicle power determination unit determines that the vehicle power is off and when the rewrite-in-progress determination unit determines that rewriting of the program is in progress, and a self-retention power instruction unit that is configured to instruct the vehicle slave device to enable the first self-retention power circuit when the first self-retention power determination unit determines that it is necessary to self-retain the power in the vehicle slave device. The vehicle slave device is configured to enable the first self-retention power circuit when the vehicle master device instructs to enable the first self-retention power circuit.