Could set p0116 code if difference between coolant temp and intake air (ambient) temp is 30 deg C or more. If you use a timer so block heater is on for no more than 2-3 hrs that wouldn't be a problem. If you leave it plugged in all night it could set the code. The ECM assumes the engine temp sensor is faulty, and sets fuel map for 80 deg C. Also runs cooling fans (if your truck has electric cooling fans). Happened on my 2005 Buick, I erased the p0116 code with a code reader, and am now more careful not to plug in more than necessary.