2007 Chevrolet Silverado Cruise Control and Remote Start Problems?

My Cruise Control and Remote Start both do not work on my 2007 Z71 Crew Cab Silverado and I would like to fix the problems. The cruise control: the light comes on but I am unable to engage it whenever I press the "Set" button. The remote start: the dealer got it to work on the lot today but I can't. I lock it and after the horn beeps I hold down the remote start button and the lights flash like it is going to start, but it doesn't. My check engine light IS on and I don't know if that contributes to these issues but I'm getting the problem fixed Monday so hopefully the two will return as well.
I tried my cruise control this morning and it worked! I was excited. Then when I went to drive it earlier tonight I tried again and it did not work. And with the remote start, I haven't gotten it to work. And I noticed today that when I tried it from inside the cab, the check engine light flashes, which makes me think that is the reason why it is not working. Hopefully the mechanic of the dealer who sold me the truck will be able to fix both issues on Monday. Hope this extra information will help.