Hi Guys, so my silverado just starting doing this( like 2 week ago).... I have a little Raised RPMs at idle(like approx 800-900) if i put the truck in 'D' it will shift into 2nd and 3rd without me pressing the gas pedal i have already changed the Throttle and MAF.. i have no dtc's but the problem doesn't seem to be going away... any ideas?

 

Does it actually have no DTCs or just not turning on the check engine light?

 

its not turning on the check engine... good point.. ill check for no check engine light DTC'S tomorrow and report back