So once again to be sure. This was working before, and is not working now?
If it was working before why do you think the "program" on the arduino is the problem and not anything else?
You can try connecting the thing to a laptop, open IDE, have the serial monitor open. Press a button and see if the monitor gives a response. But still I don't think the problem is the "program" on regarding.
Also, a manual overwrite wad installed but wrongly and was never working? Or, was it worrying before, just like the arduino, and not anymore?
Yes, it worked until 3 weeks ago.
Acctually, Im not sure what the problem is, so my first thought was to check if the arduino is working. I want to see if there was an easy way to do it.
When I connect the laptop and open serial monitor, it says STARTED, and nothing more. Nothing happens when pushing the buttons. But since I havent checked that before, when it worked Im not sure what I should expect.
The manual way to open the trunk, which is to losen to screws under the car, have never worked.