was2007 Gen 2, 80k miles. Background info: Twice recently, when driving to town in the afternoon heat (nearest town is usually about 15 degrees hotter from my home/work), I will park my car, come back to it and restart, and get the triangle exclamation point on dash with the car exclamation on the mfd. First time I drove about a 1/4 mile to the dealer, but they can't diagnose my car for 3 weeks. While in the shade at the dealer, light goes off. Dealer says probably just a computer malfunction. I noticed my oil was very low, so I topped it off, drove home, no more warning lights for weeks, figured it was the oil and didn't end up going to that appointment. Same lights under same driving conditions again about a month later. Checked oil level, it was fine. By the time I got home, car rested overnight in much cooler weather, no more warning light. Borrowed friend's OBD scanner and no codes stored. Spent hours reading priuschat. 1. Checked my 12v battery via MFD: reads 12v exact in ACC mode after car sat overnight. Note this batt was replaced exactly 5 yrs ago. Hybrid battery replaced about a year ago. Most days of the week I only travel to/from work about 2 miles apart. 2. Checked my oil level, which is fine since the last top off a few weeks earlier. Did full oil & filter change anyhow since it was overdue. 3. Checked inverter coolant pump. Last replaced under recall in Dec 2010 at 35k. In IG-ON pump sounds like aquarium pump as described, but coolant reservoir has very little movement. From youtube videos, I see that movement should be more vigorous. Is it possible that the pump is slowly failing? Or is it always a complete failure, and my pump is fine? Is that 12v battery reading above not normal? I need to drive a couple of hours to another hotter climate this weekend, and am afraid of burning the inverter on such a long trip. Looking for advice, since dealer does not have availablity til next month (I'm rural so no other dealer options).