ZR-D109 Transmission Solenoid Valve for MERCEDES-BENZ

The function of the transmission solenoid valve is to adjust the opening of the solenoid valve during the shift process to improve the smoothness of the shift. Different solenoid valves control different clutches or brakes, and play a role in different gear, each gear is controlled by one or several solenoid valves.

The role of the transmission solenoid valve: The solenoid valve is controlled by the transmission electronic control module TCU, basically the neutral and the pressure in the gear is a constant value, but the opening of the solenoid valve is adjusted during the shift process to improve the smoothness of the shift. Different solenoid valves control different clutches or brakes and play a role in different gears. Each gear is controlled by one or more solenoid valves.

Solenoid valve, mainly refers to two pressure adjustment solenoid valve, one to adjust the main oil pressure, the other to adjust the hydraulic torque converter lock the oil pressure, the two oil pressure also controls the shift valve body work in the oil circuit plate, there is a bad work, will cause the shift impact, a long time will wear out the clutch disc and brake belt in the wave box, resulting in more serious failure.

Transmission solenoid valves are roughly divided into two categories,

1: Switch type - Through a certain current or voltage, the internal coil of the battery valve is energized, and then the internal needle valve or ball valve is displaced, thereby blocking the section or opening the oil circuit. Most used to control the shift

2: pulse type ---- current duty cycle control, controlled by frequency. It is used to adjust oil pressure.