What caused the failure of mazda 5 gearbox?

The causes of gearbox failure in mazda 5 are as follows: 1, engine idle speed is too high and upshift is too late. 2. Improper adjustment of throttle cable or throttle position sensor will make the oil pressure in the main oil circuit too high. 3, the main oil pressure regulating valve is faulty, make the main oil pressure is too high. 4. The piston of the damping accumulator is stuck and cannot play a damping role. 5. The steel ball of the check valve is lost, and the shift actuator is engaged too fast. 6. The actuator slips and the oil pressure solenoid valve does not work. 7. The electronic controller (TCU) is faulty. The performance of mazda 5 gearbox failure is as follows: when starting, the car vibrates seriously when shifting from parking gear or neutral gear to reverse gear or forward gear; When driving, the car has obvious impulse at the moment of automatic gear upshift.