Triangle of doom

Had a scare while coming home, the Exclamation point triangle came on for a couple secs, then went away. Did this about three times. I was about 20 minutes minutes from home, I stopped turned off the car, checked under the hood, no smoke or smell. Jumped back on the freeway and it came on again, this time I glanced at the screen and the little temperature icon came on in the corner, again, the light went off. Got home and pulled the codes, my father in law looked under the hood and the cap to the coolant wasn't screwed on so he screwed and tightened it. The codes came up P1116 COOLANT TEMPERATURE SENSOR (CTS) CIRCUIT STACK FOR COOLANT HEAD STORAGE SYSTEM & P1121. COOLANT FLOW CONTROL VALAVE POSITION SENSOR CIRCUIT STACK. It would be more than awesome if the codes and light problem were just due to the cap basically being off, but I have a feeling it isn't that simple. One can hope right? So, does anyone have any experience in this? Thanks in advance!