Mechanic can't connect to computer

[2nd_Amdt]

I have a 2010 Boxster base, 6 speed. Last year I put in an after market radio to get a backup camera. Several months later, the radio died. Just wouldn't do anything; it was not the fuse. Since it was winter and I wasn't driving it much, I did not immediately pull the broken radio. Several weeks later, I started it up to take it around the block before a major snow storm hit, and my engine light immediately started flashing, so I shut it down. I had it towed to my mechanic and he couldn't get his computer to read my car's computer - he said it just wasn't registering anything. So, on a whim, we swapped the broke radio for the oem radio that I had kept. He could then get his handheld unit to read codes, and could see that it recorded a cylinder misfiring at some point, but was no longer doing it.

We assume that the broke radio somehow made the computer act up, throwing a code. At this point I have left the oem radio in, the backup camera is still physically there but is not attached to anything. But even after running it several thousand miles, he still can't get his main diagnostic computer to connect and read my computer. Engine codes can still be read by his handheld unit, but it has been running fine so no further codes have shown.

I'm looking for any suggestions or experience on something like this. I'd really like to put a new radio in it and get the backup camera again, as well as bluetooth streaming. But I'd really like to get the diagnostics back online so that I can stay ahead of maintenance issues.

[yelcab1]

My educated guess is the Radio died because something in its power supply shorted out and killed it. In the process, it shorted the 12V positive to something close to ground making your car act up. When your mechanic removed the radio, he removed the short and the car is running OK again. But, the battery has probably died a premature (or well deserved) death and is now refusing to connect to the diagnostic port.

Change the battery, let it reset, and see where you are.

[2nd_Amdt]

Thank you! I will check this out!