The fault of Pwm solenoid valve will directly affect the action of switching valve and regulating valve. Common faults include Pwm solenoid valve failure, should be investigated from the following aspects:

If the solenoid valve joint is loose or off, the solenoid valve shall not be energized, the joint can be tightened.

If the solenoid valve coil is burned out, remove the wiring from the normally closed solenoid valve and measure it with a multimeter. If the circuit is open, the solenoid coil will burn out.

The reason is that the ultra small solenoid valve coil damp lead to poor insulation and magnetic leakage, resulting in excessive current in the coil and burn, need to prevent rain into the solenoid valve. In addition, if the spring is too hard, the reaction force is too large, the coil turns too small, the suction is not enough, the coil will burn out. In case of emergency, the manual button on the coil can be moved from the "0" position to the "1" position during normal operation to open the valve.

The Pwm solenoid valve is jammed. The fit gap between the spool sleeve and the solenoid spool valve is very small (less than 0.008 mm) and is usually assembled in one piece. When there is too little mechanical impurities or lubricating oil, easy to jam. The treatment can be done by using a wire to snap the hole back through the head. The fundamental solution is to remove the solenoid valve, remove the spool and its sleeve, and clean it with CCI4, so that the spool can move flexibly in the valve sleeve. When disassembling, pay attention to the assembly sequence and external wiring position of each component, so as to facilitate reassembly and correct wiring. Also check whether the spray hole of the oil spray injector is blocked and whether the lubricating oil is sufficient.

Air leakage. Leakage can cause insufficient air pressure to open and close the forced valve. The reason is that the gasket is damaged or the slide valve is worn, causing several cavities to inflate.

Choose a proper time to handle the fault of the high voltage solenoid valve of the switching system, and handle the fault when the high voltage solenoid valve is powered off. If the treatment is not completed within the switching interval, the switching system can be suspended and handled calmly.