A system for updating software installed on an electronic unit on a vehicle can include a processor and a memory. The processor can be disposed on an intermediate communications device. The intermediate communications device can be a mobile device. The memory can store an update request module and an update existence module. The update request module can include instructions that when executed by the processor cause the processor to receive, from the electronic unit on the vehicle, a request for an update of the software. The request can include: (1) an identification of a version of the software currently installed on the electronic unit and (2) a key to specifically identify the electronic unit. The update existence module can include instructions that when executed by the processor cause the processor to receive, from a device associated with development of the software, information about an existence of the update.