According to an aspect of some embodiments of the present invention there is provided a vehicle mechanism for handling vehicle electronic control unit (ECU) malfunction, comprising: a first set of vehicle backup ECUs for operating in a backup vehicle driving mode comprising read-only firmware and disconnected from an interface with communication networks outside the vehicle, the vehicle backup ECUs providing at least basic driving related features of the vehicle including transmission and engine controllers to provide control of the vehicle; and a controller that switches from a standard vehicle driving mode operating according to a second set of standard vehicle ECUs to backup vehicle driving mode in response to a trigger indicative of malfunction of at least one ECU of the first set of vehicle ECUs.