[cdtwoaway]

Literally: I have successfully sent CAN messages that were understandable to ECUs with an Arduino while waiting for a delivery of real hardware. There are Arduino-GSM shields that are super easy to use and would be remote-accessible.

Such a device would be dead easy to build even for someone who has almost no experience in electronics.

[gh02t]

You can also buy plenty of development boards with an ESP32 and a CAN transceiver. Small, fully programmable, with Wifi and BLE, for less than $50.