After reading the data value of solenoid valve N280, the current increases gradually from 5mA to 0.82a, and the load of the air conditioning system increases gradually from 0N·m to 5N·m (generally, it is only effective when the air conditioning reaches above 4N·m). It can be seen from the comparison results that the solenoid valve N280 also works normally. Then drive out to test, confirm the air conditioning system to return to normal after the customer, 3 months after return, everything is normal, the fault has been completely eliminated.