Electronic engine control apparatus having improved configuration for ensuring excellent engine startability

An electronic control apparatus comprising:

• a first storage means which is electrically rewritable and nonvolatile and in which engine control software for controlling an engine of a motor vehicle is stored;
• a second storage means whose contents are retainable when power to the electronic control apparatus is removed;
• and
• a processor that performs processes of
• executing the engine control software stored in the first storage means to control the engine,
• storing in the second storage means retention data that is generated through execution of the engine control software and to be retained even when power to the electronic control apparatus is removed, and
• rewriting the engine control software stored in the first storage means with engine control software sent from an external device or circuit upon receipt of a rewrite request from the external device or circuit,
• wherein
• the engine control software includes a plurality of functional blocks each of which is for performing a specific function,
• the retention data includes a plurality of retention data blocks each of which is associated with one of the functional blocks of the engine control software,
• the electronic control apparatus further comprises a plurality of third storage means whose contents are retainable when power to the electronic control apparatus is removed and in each of which a piece of specific information on a corresponding one of the functional blocks of the engine control software is stored,
• when the electronic control apparatus is activated, the processor further performs, for each of the functional blocks of the engine control software, an initialization control process which includes processes of
• extracting a piece of specific information on the functional block of the engine control software from the first storage means,
• determining whether or not the piece of specific information extracted from the first storage means is coincident with that stored in the corresponding one of the third storage means,
• initializing the associated one of the retention data blocks in the second storage means when the piece of specific information extracted from the first storage means is determined as being incoincident with that stored in the corresponding one of the third storage means, and
• updating the piece of specific information stored in the corresponding one of the third storage means with that extracted from the first storage means upon completion of the initializing process, and
• the processor starts performing the process of executing the engine control software stored in the first storage means before completion of all the initialization control processes for the functional blocks of the engine control software.