Yesterday I drove to the grocery store, no problems. Early in my drive home, I noticed the ICE doing an irregular heavy shaking whenever I was accelerating. (Not the usual shudders associated with it turning on and off during hybrid operation.) Shortly after, the check engine light came on. I paid close attention to the console's energy-flow display, which seemed to show the usual patterns (no warning messages or anything). But now the battery indicator is down to three blue bars, which is lower than I've seen it before. I'm not sure if this means that the regenerative braking isn't actually charging the battery or if the car has chosen to rely more heavily on the electric motor given the ICE's difficulties. I made an appointment with the dealer for Wednesday morning (in about 48 hours), and am wondering if there's anything I can check on my own before then, and also how dangerous it would be to try driving it before then. 2005 model year, ~50,000 miles. I just bought it used (toyota certified, from a dealer) about 4 months/2,000 miles ago. I haven't had it serviced since then. Outside temp ~50F. Any thoughts? Thanks!