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Q: Why is my auto transmission down shifting to the wrong gear when decelerating?

asked by on November 17, 2016

When decelerating through 20 mph the automatic transmission shifts into a lower gear that causes the car to lurch/jerk. It only happens when passing downward through 20 mph and it feels like the car drops into first gear at a speed to high for that gear.

My car has 115000 miles.
My car has an automatic transmission.

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Transmission Fluid Service $140.08 - $502.73 Get a Quote
Transmission Oil Pressure Switch Replacement $158.32 - $745.73 Get a Quote
Car is hard to shift Inspection $94.99 - $114.99 Get a Quote
Or For Any Other Auto Repairs Get a Quote

Improper shifting, either up or down, can be caused by a few different issues. If the transmission fluid condition or level are not correct, this can cause erratic shifting. Servicing the transmission may resolve the issue. Other causes can be the transmission fluid pressure sensor. If the pressure sensor is faulty, the engine/transmission control unit can cause erratic shifting, even skip gears when up or down shifting. Also, the transmission temperature sensor can also be at fault which is a common issue with this vehicle and transmission. I owned the exact same vehicle for several years. Have a certified technician look into the transmission shifting issues to isolate the correct cause.

Hyundai
Sonata
2009
L4-2.4L
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