Update system, onboard apparatus, and server

An update system comprising:

• an onboard apparatus;
• and
• a server,
• wherein the onboard apparatus includes:
• a first trained model configured to receive, as input data, a first vehicle value transmitted over an onboard network to which the onboard apparatus is to be connected, and output an estimated value correlated with the first vehicle value;
• and
• a first determination unit configured to compare the estimated value output from the first trained model with a second vehicle value transmitted over the onboard network, and determine whether or not the first trained model is compatible with a vehicle,
• the server includes:
• a selection unit configured to select a second trained model for updating the first trained model if the first determination unit determines that the first trained model is not compatible with the vehicle;
• and
• a transmission unit configured to transmit the second trained model selected by the selection unit to the onboard apparatus, and
• the onboard apparatus includes:
• a receiving unit configured to receive the second trained model transmitted from the server;
• and
• an update unit configured to update the first trained model to the second trained model received by the receiving unit.