code p1296 coolant system malfunction
cts and circuit

 

Sounds like your car needs a stat.

 

I would say actually try touching the coolant hoses to see if they feel cold or not, your gauge could be malfunctioning on you. If it feels like its colder than it should be after driving 10 minutes then you most likely need a thermostat like others have said.
If the hoses feel really hot but the gauge says its cold then put in a CTS coolant temp sensor thats behind the engine, its about $40.