I've recently put my car in 4LO realize that the crawl control speed control (when crawl control is on) or terrrain type selector (when crawl control is off) is not working. It just stuck on the lower 2 levels and not able to get to the top 3 levels. Does anyone else experience this issue before? I'm not sure if I've accidently spilled something on the button and probably dirty the contact. if so, is there an easy way to replace or clean up this button?