Harsh Downshift
WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
| Checks |
Causes |
| Control Valve Body Assembly |
- Check the engine for diagnostic codes. If the engine controller signals the transmission that engine torque is inaccurate, the transmission will command high time pressure.
- Inspect for worn, sticking or damaged pressure regulator valve (309) or pressure regulator valve spring (308) Gen 1 / Gen 2 or pressure regulator valve (310) or spring (309) Gen 3.
- Inspect for stuck actuator feed limit valve (430) or spring (431).
- Inspect for stuck clutch select valve (428) or spring (427).
- Inspect for stuck 1-2-3-4 clutch regulator valve (417) or spring (416).
- Inspect for stuck 1-2-3-4 clutch boost valve (414) or spring (415).
- Inspect for stuck 2-6 clutch regulator valve (419) or spring (418).
- Inspect for stuck 3-5 reverse clutch regulator valve (421) or spring (420).
- Inspect for stuck low reverse and 4-5-6 clutch regulator valve (411) or spring (410).
- Inspect for stuck low reverse and 4-5-6 clutch boost valve (436) and spring (437) Gen 2 / Gen 3 only.
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