check engine light is on but when i turn the key 3 times to check code there is none. is it possible that it is caused by not turning off the oil change light. Thanks for any insight.

 

also i am experiencing a vibration at 70 and gets worse as the speed increases also the truck pulls right pretty well. just want to be knowledgeable when i go to the dealer so i can get everything fixed the 1st time. truck has 10k miles. thanks