I have what seems to be a speed sensor issue with my 2000 Grand Prix GT, but here's the kicker! I have tried 4 separate speed sensors that I know were good, with no improvement. The wiring is good. I have checked and rechecked. It sets no codes. Weird thing is when it's really cold it works flawlessly. Cruise works, speedo, trans, everything until it warms up. Can ATF expanding with increase in temp. Cause a distortion with the speed sensor and reluctor? I will be dropping the pan for service and inspection tomorrow. Let me hear some ideas. Also any recommendation for ATF? 160k miles on car. Thanks guys!
