2013 Silverado V6 2wd auto hard shift 1-2

[2013 Chevy W/T]

So my Silverado has 63k miles on it and it started to shift hard (Very hard slam) between 1st and second gear. Along with that the check engine light came on. I plugged my diagnostic tool in and it flashed 2 codes. P0961 and P0700. When I reset and cleared the code, it stopped for about a day and then stated again. I cleared the code and again it drives fine for about a day and starts again. Being that it stops by simply clearing the error code I am inclined to think the problem is electronic and not a broken solenoid in the trans. Has anyone encountered this before? 

[sefiroxx]

Your 1-2 accumulator is probably cracked, or the spring is broken. Simple to access when dropping the pan

[swathdiver]

12 hours ago, 2013 Chevy W/T said:

So my Silverado has 63k miles on it and it started to shift hard (Very hard slam) between 1st and second gear. Along with that the check engine light came on. I plugged my diagnostic tool in and it flashed 2 codes. P0961 and P0700. When I reset and cleared the code, it stopped for about a day and then stated again. I cleared the code and again it drives fine for about a day and starts again. Being that it stops by simply clearing the error code I am inclined to think the problem is electronic and not a broken solenoid in the trans. Has anyone encountered this before? 

P0961 is for the Line Pressure Control Solenoid System Performance

 

This code can set when the battery voltage gets too low, either due to excessive electrical loads or a failing battery.  If the battery is good, it's either the wiring harness or the solenoid, you do not need to rebuild the whole transmission...  Do some googling, I've got to run...