[dougc905]

This is what happened to me when my NOx sensor went. Warning light, countdown, then it went away. The code stayed in the computer though.

Well I stop at the supermarket come back out start the car and the message is gone after it was down to 21 miles to 65 max speed. Still going to drop it off at dealer and see if it stored a code. I drive almost 200 miles a day , dont need it to pop back up and cant make it home Tuesday

 

[dougc905]

My car didn't go into count down when the DEF heater went. Just threw a checklight.

It is most likely the def tank heater, is now on recall for 10 years 120,000 miles. They replace the whole tank. I would go to Auto Zone to read the codes,then if out of warranty repalce it myself.