+1 for this issue.
Wire had chafed from the battery cable and a simple fix of unscrewing the solenoid and disconnecting the wiring harness, soldering and taping the wires, and then putting it back resolved the issue (code didn't return after erasing and boost returned to nomral).
I started off by searching TDR for the P0243 code and immediately got to root cause. I was curious what info was on the rest of the Net but came up empty on Google and Bing (other forums had folks hitting the code but nobody had a resolution for it). I just justified my TDR membership this year! Thanks to Grbow for the offline help. .