Could a leak in coolant system throw on em light?

Bin having problems with fault code p1296(error in mapped cooling system) ive changed the stat and temp sensor. Stat was defo faulty as cant beleive difference in heat! Have reset the code yet it still comes back. I noticed a sort of burning smell coming from under bonnet and googled it and a possible was a leak in cooling system?? Im not a 100% but im sure wen i put on the heated rear screen the light cane back on. Maybe not connected. Please help as that bloody engine management light really gets on me nerves!