2020 gmc 3500 Denali duramax with 38000 miles and my check engine light just came on. Any ideas or has this happened to anyone. Also does autozone scan these?
I have a 2018 L5P and have had this situation a few times during my 38K miles. I used to take it to the dealer everytime, and they would research and find no issues, thus reset the code.
1) Are there any other indicators like poor performance, or any of the gauges providing odd readings? If so, schedule a dealer visit.
2) If not, here is something else i learned: the check occurs each time you start the engine. I recommend that you always let the full cycle of auto checks occur prior to starting the engine. if the fault doesn't repeat for 13 straight times, the check engine light will go off. I was told by the dealer that the ECM is extremely sensitive to emission signals
3) I have also learned how to clean the MAF Sensor. The first time i took it out, i couldn't believe how much soot had built up on the little blue sensor. Just clean and reinstall. I believe it has greatly increased my fuel economy.