The speedometer can go bad itself.
I had one stop working because the odometer gears got bunged up. It actually melted.
In your car the speedometer siognal puts out what is called a Hall Effect and it is used for fuel management and the cruise control.
Have you had any problems with either?
If not, it is a fully electronic signal and can still affect tannsmission shifts and anything dependent on a speed signal, (if it is picking it up from speedometer as oppsosed to the speed sensor.
Have you changed the tire and rim sizes?
September, 14, 2011 AT 4:52 PM
No problem with fuel and the car has no cruise control. But it does effect the trans shift. When the speedmeter is working, the car sifts fine. But when it starts jumping, the trans sifts up and down, or when the speedmeter stops working the trans will not shift at all. Is it the speedmeter? The speed sensor is good. New Thank you
September, 14, 2011 AT 9:38 PM
Yes, the car computer is feeding from the signal somewhere between the sensor an speedometer to tell the transmission when to shift to save gas or for performance. More than likely, the signal might go into the computer then get split and wait for feed back form the speedometer. This is because you can overide the system and shift manually at the speed you choose, (until the rev limiter hits).
So, you probably have a problem with the speed omter. Speed sensors are less complicated and have one moving part and a pickup for the radial signal.
Good luck and let me know how it turns out. If you get a used one, get a Haynes manual or a dealer to the you how to test it.
September, 15, 2011 AT 10:53 AM
Thank you so much. I will let you know how it goes. Have a great day.
September, 15, 2011 AT 3:13 PM
No problem. You are quite welcome and it will be interesting to see what comes of this.