hey guys for the past week or so when i've been driving i've turned my A/C on instead of rolling down the windows because here in MD it has been HOOOOOOTTTT. anyways i noticed that ever since i have been using my air conditioning while driving consistently, my speedo has been working. no D4 flashing, no fluctuationg needle, nothing. i even tested it, i started driving with the ac on and it was working so i come to a stop light, roll down my windows turn off the ac. and like 30 seconds after i start moving again the speedo acts up and the D4 flashes. so i turn my AC back on and roll up the windows, and at this point the D4 is still flashing but the speedo goes about functioning again without a fuss. weird huh? maybe it's just me? but this has worked consistently for a bout a week. someone else try n see if works for you too.