02-16-2007, 02:55 AM
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Member
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Join Date: Feb 2007
Location: NYC
Posts: 17
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Quote:
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Originally Posted by JCL
You are right, it is my deductive reasoning. I pointed out that if the transmission had accelerometers that knew the vehicle speed, it may as well tell the speedometer so they could both benefit.
I am aware of the device. It is reasonably accurate over a quarter mile. Then it must be reset.
Let me know if you find a Gtech inside your transmission.
Here is the link for the transmission speed sensor. It is item 4. There are two of them. Looks a lot like a magnetic pickup. It counts the revolutions of a shaft, and converts that into a rotational velocity. That shaft speed converts to a vehicle speed via the final drive ratio and tire diameter. Not sure of your model, but this is for the latest 3.0 X3 they had.
http://www.realoem.com/bmw/showparts...97&hg=24&fg=15 |
Again, I never said it didn't have a speed sensor. All I'm stating is that the ECU that is controlling Transmission, X-drive, DSC has accelerometers that tell it actual vehicle speed, lateral acceleration, yaw and pitch among other things. In fact the GM 6L50 transmission in the 07 X3 has Performance Algorithm Shifting, a transmission algorithm that looks at lateral acceleration from accelerometers, throttle, and vehicle deceleration activity to determine if the vehicle is being driven in a sporty manner. If the algorithm recognizes these conditions, it can force downshifts and hold lower gears for optimized vehicle performance.
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