My service engine soon light is on and my transmission has lost power in overdrive and 3rd gear upon acceleration. So when I accelerate I have to shift to 2nd then back to overdrive. Other than that my transmission runs fine. This all started when I scraped my entire undercarriage real bad. The little light that indicated which gear you're on shut off and then the transmission loses power. The light will come back on ever so often and the transmission runs normal with all its power and everything. So I know my transmission is not bad it's electrical but what exactly is it? Can you help give me some pointers?