P0842 fault code

Predictably, the morning that we were supposed to leave on vacation, the Vue
started shifting very roughly. I had filled the tank the night before so
suspected bad fuel. Put in a can of drygas and hit the highway. About 10
miles into the 200 mile trip, the MIL light came on. Pulled over and started
pulling fuses (the lw300 ECU could be reset by pulling the controls B+
fuse). No dice, couldn't find a fuse that would turn off the light. Drove
all the way with the transmission slamming from gear to gear. It was like
the torque converter stayed locked up. Interesting that the shifter normally
defaults to 3rd gear when you shift to manual and you can shift up or down
from there. Now the manual defaults to 4th gear and the up/down buttons are
not functional.

Finally made it to destination (enduring wife's diatribes that we bought a
POS) and after unloading the car, fished out my AutoTap tool and laptop.
Showed P0842 "transmission fluid pressure sensor "A" circuit Low." I haven't
been able to make sense of this yet. Did a reset of the fault codes and car
is driving fine now. Drove it for about 50 miles today and light has not
come back on. It likely will so looking for possible causes.

2009 Vue XE with 2.4L EcoTec and 4T45 base model transmission