My name is XXXXX XXXXX I am a professional here at Just Answer. I noticed that your question was not getting a response and thought I would ask to see if you still need help with this.On allot of vehicles the outside temperature display can take time to update to the correct temperature as they don't want the temp sensor picking up engine or radiator heat and giving incorrect signals.If the dealer still thinks this is an issue and isn't the normal operation of this and they have replaced the sensor itself they should check the wiring coming from the sensor to where it leads as well as the operation of the display panel as one of these components would most likely be at fault here.From what is described though and what I have found it sounds like this vehicle has this delay in updating the outside temperature signal.I hope this has helped in some way here.If you need anything else don't hesitate to ask thats what I am here for.Thanks Pete
Thanks, XXXXX XXXXX comparing the operation of this sensor to that of my Kia Sportage 2006 model. There the temperature reading was real time. I just find it strange that the Hyundai Elantra 2012 model is real time. I left my vehicle in the 35deg C sun for 3hrs and then got in. The temp showed 26deg C. It took about 40 minutes before the gauge showed 34deg C.