Once in a while my 2002 Lancer ES (about 125,000 miles) shakes and then the check engine light comes on. When I checked the code, it says my shift upswitch circuit requested and upshift and there was no response from the transmission. If I pull over and restart the car it works fine and has no problems shifting at all, and eventually the light will go off by itself, only to return a couple of weeks later. Has anyone run into this problem before? It sounds like an electrical issue but I'm wondering if I should start planning financially for a tranny repair...