The arrow was flashing again this morning all through my commute to work. When I arrived, with the engine off, I rowed through the gears (R-L) as you suggested, turned off the key, turned it back on, and the arrow was still flashing. I took the car to go to lunch, though, and no more flashing. DO you think I need a new PNP switch, even though the one I installed is only about 16 months old, or might there be another reason. I am tempted to just wait until it happens again (and try the same fix), but I don't want to do damage. How important is the PNP switch? What does it do? I replaced it before because the reverse lights were not coming on, but they are still working.