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Q: The car is not accelerating right and the speedometer is jumping.

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So usually when I am at a stop sign or going at lower speeds the car will go for a bit then I lose all power and it stops then I'll try again and it happens again 1 or 2 more times then it will go. Also when this started happening the speedometer jumps up a lot.

My car has 183500 miles.
My car has an automatic transmission.

A: Hello. The speed info goes from the VSS (ve...

Hello. The speed info goes from the VSS (vehicle speed sensor (transmission output sensor)) mounted on the tranny, to the PCM (powertrain control module (computer)) mounted on the passenger firewall, to the dash speedometer. If the speedometer is not functioning properly, you're more than likely going to have erratic shifting problems as you have indicated. If you need to have this checked, a qualified professional from YourMechanic, can come to your car's location to diagnose the lost power and speedometer problems. If necessary, they can replace the speed sensor or perform any other repair that is recommended.

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