Transmission harsh downshift

2001 SATURN SL2
225,000 MILES • 1.9L • 4 CYL • 2WD • AUTOMATIC
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MASTER YODA
  • MEMBER
  • 1 POST
Transmission downshifts harsh when driving in high gear at highway speeds.
Sometimes it will bang really hard, seems worse at higher speeds.
Replaced the valve body with a re-manufactured one with Sonax pressure valve update.
Checked the clutch nut and it is tight.
No codes.
May 8, 2018 at 2:13 PM
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JIS001
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 3,412 POSTS
If the valve body was replaced then you will need an advance scanner to reset the adaptations and performe an adaptive test drive.

As componnents wear the transmission control module adapts to that wear so when a new part is installed the computer does not know that until you reset the memory. Now given the mileage, if resetting the adaptations and doing a relearn, if the condition does not improve then you will most likely need to have the whole transmission rebuilt.
May 8, 2018 at 11:06 PM
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