why wont my car stat first thing in the am when its cold outside

Try this. I found this from someone having the problem you are experiencing: This is something that Sonata owners who have push button start need to know in case of the brake switch malfunction. What happens is when you go to start the car, it will not start and the screen on the dash tells you to press the brake pedal to start the engine. Naturally your instict is to press the pedal harder, this wont help. Here is how you can start you car without pressing the brake pedal. First take your foot off the brake pedal. Next push the start button one time. THen press and hold the start button again for roughly 10-20 seconds. The car will then start. Important thing to remember is you WILL have brakes....but you WILL NOT have brake lights if the switch is malfunctioning. Also it seems that the switch will intermitenly work, then malfunction, then work again etc...till it completly malfunctions. It is covered under warranty. Just a little FYI for everyone....didnt see it posted anywhere else.

i will try this, today my husband was driving the car and when he was at a light and the light turned green he went to push the gas and the car was off not moving so they push it and when he tried to start the car it wont start but all of the lights came on, then he said key not detected so we change the key battery then he tried to start the car again and he seems like it want to start but did not, then when the tow truck came and they tried to put the car in neutral it didn't even move like it didn't recognize the key. could it be something wrong with the key program to the car. please help me with this question