My vehicle (LS1B PCM) is licensed and tuned, new battery in good condition. I went to routinely read/write it for like the 100th time lol and it says "FAILED TO UNLOCK". I am not sure what gives, tries most of the common sense basic things and still.
When I go to read it acts as it has a custom lock by another tuner (impossible) and when I go to cal. or full flashed it says not licensed (impossible).
All of this happened on it's own, and if it helps at all I recently ran my 4 year old battery dead by having the key on / engine off to test and replace a blown instrument cluster fuse. I installed a brand new good and proper battery and the car runs great except... for some possibly unrelated reason it now idles slightly and intermittently high. Meaning the "dashpot" (?) it likes to sit at 1100 RPM for no reason until it settles.
What happened to my PCM communication with tuning device and what to do please?
Greatly appreciate in advance you time/attention/clues/help/suggestions!
Don't want to buy another module until I am sure and I understand the cause. Money is tight and an accurate diagnosis is essential. But I am only halfway done tuning this piggy :(
Vehicle is 2001 Z28 manual / stock LS1 - bolt ons if it helps