Thread: Speedo, cruise control, and delayed shift issue

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!

Standard Dexron 3 is the fluid for that year car, any brand will do.


Have you tried cleaning the MAF sensor?? I know that if its super dirty it can affect how the car shifts and drives.

Though it seems you have more than 1 issue here as 3 different things are affected. It's kinda hard to guess at what all is going on.

You say speedo/cruise and shift. What is going on with speedo/cruise?

Tonight's stab in the dark: Your throttlebody is possessed.
I mean, have a look and see if it's gummed up or something. Hopefully it's that simple.

What all turns on at 160* aside from knock sensors?

Some reading: http://www.tripleedgeperformance.com...cillation.html

I'm thinking a little differently. Speedo is going to affect shifting etc. Pull the VSS sensor and clean the metal fragments off it. If there's anything more than a paste on it.. take pics.

Ok.. sorry, forgot what you had posted. Skip the pulling of the sensor then. That would be a waste of your time. The reluctors are pressed on and IIRC Drunkie had found a link at one point that linked some trans shifting issues to the reluctor swelling and giving bad readings.

Or pull the passenger axle, diff cover and put a different reluctor on the diff.