After driving most of a day on the road a red triangle warning light came up on the dash and a PCS System Check light lit together with a Check PCS Sytem message in the display site. I checked the fuses and they seem to be Ok. The car runs fine and I don't feel any effect on driving the car due to this message.

 

If my assumption is correct PCS is the Pre-Collision System. The vehicle has sensors that may need to be cleaned. Did the front of your vehicle get extra dirty on this all-day road trip? You may just need to wash it. If that doesn't work the sensors may need to be re-calibrated, or replaced.

BTW, what year and model do you have?

 

2007, es 350.