Car Problem Reports

Hyundai Sonata Confirm Latest Software For Transmission Control Module and Correct Fuild For Proper Shift Quailty

Hyundai Sonata Problem
28 Reports
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Model Years Affected: 2007, 2008, 2009, 2010

Drive Train Affected: Automatic Transmission

Average Mileage: 53,537 mi (10,000 mi - 96,000 mi)


Prior to replacing the automatic transmission fluid (to improve shift quality), make sure that the transmission fluid level is correct. Also, make sure the computer that controls the transmission has the most up-to-date adaptive programming information. When servicing these transmissions be sure to use fluid approved by Hyundai.

  • Visitor, , Automatic Transmission, 65,000 mi

    I noticed that my car is beginning to down shift with a hard thump at 20mph. Has anyone had this problem?

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  • Visitor, , Automatic Transmission, 80,000 mi

    Last year my Sonata started downshifting when driving on the freeway, on its own. I paid over $100 to get the dealer to fix it. They said it was a software glitch and they fixed it by loading new software. That was 2013. Now (2014) it downshifts hard when I'm braking in city traffic. If I'm going to have to pay this every year, I may be done with Hyundai. Other than this problem, it's been a great car. Hyundai needs to take ownership for this defect.

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  • Visitor, , Automatic Transmission

    HARD down-shift always between 20 - 25 mph.

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  • Visitor, , Automatic Transmission, 71,000 mi

    Hard violent downshifts when drive car while cold. Almost disappears after warmed up. Harder upshift when cold. Will be taking to a dealer to diagnos issue.

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  • Visitor, , Automatic Transmission, 65,000 mi

    Each morning when coming to a stop harsh down shift into 1st gear, but will go away after warmed up. Took into dealership and they did update to ECM, which was not covered under warranty, so much for the 10yr 100,000 mi warranty.

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  • Visitor, , Automatic Transmission, 96,000 mi

    not fixed, I shift into neutral, when coming up to stop signs--Jerky downshift -- if I don't put it in neutral.

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  •  Rookie

    At times,before reaching normal operating temp.transmission would shift into next gear with a very very hard jerk.This would not happen all the time.Thank you

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  • Visitor, , Automatic Transmission, 82,000 mi

    Trans downshifts hard into low when cold, actually making a "thump" sound

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  • Visitor, , Automatic Transmission, 30,000 mi

    Abrupt downshift at around 22mph when decelerating.

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  • Visitor, , Automatic Transmission, 75,000 mi

    hard downsift to 1st

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