if you got a series 1 1993 supra, you gotta take that top panel off with all the warning lights and the odometer attached to it, and you have to cut a wire on the odometer cables and jump it on another cable, search it up on supra forums.com there is the info there on which cables to do. i had my auto doing the same thing i did the trick and it worked never came on again. The ecu doesnt know how fast the car is going right now, so its in the safe mode, so it will shift rough, and it cut off all of the limits from the ecu, so its got no speed limiter anymore (if your car is j-spec) but you can blow it up if you rev the shit out of it, is what i heard.