An abnormality determination system that determines an abnormality of an electronic control unit mounted on a vehicle, the abnormality determination system comprising:
- electronic control units;
- and
- a processor connected to one or more of the electronic control units via a first communication bus and connected to one or more of the electronic control units via a second communication bus, wherein the processor is configured to:
- in response to an activation request via the first communication bus, the second communication bus, or both the first communication bus and the second communication bus while the vehicle is parked:
- before performing a predetermined power supply control, measure values of currents that flow through the one or more of the electronic control units connected to the first communication bus, flow through the one or more of the electronic control units connected to the second communication bus, or flow through any combination of the one or more electronic control units connected to the first communication bus or the second communication bus,
- perform the predetermined power supply control for the one or more of the electronic control units connected to the first communication bus, the one or more of the electronic control units connected to the second communication bus, or any combination of the one or more electronic control units connected to the first communication bus or the second communication bus, and
- after performing the predetermined power supply control, measure values of currents that flow through the one or more of the electronic control units connected to the first communication bus, flow through the one or more of the electronic control units connected to the second communication bus, or flow through any combination of the one or more electronic control units connected to the first communication bus or the second communication bus,
- if there is a specific electronic control unit of the one or more of the electronic control units connected to the first communication bus, the one or more of the electronic control units connected to the second communication bus, or any combination of the one or more electronic control units connected to the first communication bus or the second communication bus for which the measured values of current have changed, store information on the specific electronic control unit, and
- if there is no electronic control unit of the one or more of the electronic control units connected to the first communication bus, the one or more of the electronic control units connected to the second communication bus, or any combination of the one or more electronic control units connected to the first communication bus or the second communication bus for which the measured values of current have changed, store information on the first communication bus, the second communication bus, or both the first communication bus and the second communication bus that received the activation request, wherein:
- the processor performs, as the predetermined power supply control, control in which the one or more of the electronic control units connected to the first communication bus, the one or more of the electronic control units connected to the second communication bus, or any combination of the one or more electronic control units connected to the first communication bus or the second communication bus are turned off one by one;
- and
- a value of current flowing through each electronic control unit is measured after each corresponding electronic control unit has been turned off.