[sperry]

On STIs the cruise light is kind of a "CEL Lite"... i.e. it flashes for issues that aren't CEL worthy but are issues nonetheless, and not necessarily cruise control related. Many STI owners mention seeing flashing cruise lights in addition to their CELs.

That said, the bucking happened to me when my speed sensor popped out (due to a bad install after my clutch was replaced under warranty at about 14k miles). Basically the car drove normally up to about 4000 rpm then hit a brick wall because the rev limiter was dropped in limp mode. But it was easy to know it was the speed sensor because my speedo read zero. If your speedo's working it's not a wholesale mechanical faliure of the speed sensor like I had.