I noticed the same thing happened to me while I was on my way to the dealership to have the remote start diagnosed (for some reason, it just wouldn't work, it'll beep once instead of the 2nd beep indicating that it'll start). It definitely is an uncomfortable feeling for sure, to suddenly lose power steering at high speeds. While you still have control of the vehicle, it takes much more effort to turn the wheel, which isn't something I'd want my wife to experience being a petite woman herself. The power steering failed for about 1 km going at 100 km/hr, and then went away.
Either way, the dealership couldn't find any error codes from the power steering, but stated that there were multiple low voltage error codes when trying to perform a remote start. They believe that the poor voltage can cause the power steering to fail, which I suppose makes sense considering other electrical things can fail, such as lights that flicker for instance, when a battery is weak. They inspected and diagnosed the battery, which didn't have any issues other than the low voltage. After a recharge of the battery, everything seems to be in order. I've been monitoring the voltage as I drive, and when its between 14.4 V - 14.6V, everything works like a charm.
Being in Calgary, we've definitely seem some extremely cold weather as of late (-35 °C/-37 °F), and I'm sure most of Central USA has been seeing it too. For now, I'm going to say this is a weather related issue, and I'm sure the quick start and stop driving on short errands certainly doesn't help the battery when temperatures dip down this low.
2018 Pacifica Touring-L Plus, Billet Metallic
- S Appearance Package + 20" Wheels | MOPAR Front & Rear Splash Guards | Hands-Free Sliding Door & Liftgate | 3M Protection (Front & Rear Bumper, Hood, Wheel Wells, Mirrors, A-Frame, Door Sills)
- 8 Passenger Seating | 3D MAXPider All Weather Floor Mats | Husky Weatherbeater Cargo Liner | Uconnect 4C
- Build Date: December 27, 2017