維修技師通過試車發現變速箱只有2檔、4檔、6檔、倒檔，除了黃色齒輪燈點亮以外，還發現儀表顯示屏會顯示“變速箱故障功能限制可繼續行駛”的字樣，用診斷儀檢查，報有子變速箱1故障(主動/靜態)故障碼。

The maintenance technician found through a test drive that the gearbox only has 2nd, 4th, 6th, and reverse gears. In addition to the yellow gear light on, they also discovered that the instrument display screen would display the words "Transmission fault function limit can continue driving". After checking with a diagnostic tool, a fault code (active/static) for sub gearbox 1 was reported.

首先從故障碼的字面上來理解故障問題，子變速箱1是指奇數檔，根據資料得知，閥3就是控制奇數檔動力傳遞的管理K1離合器的電磁閥N435。故障性質既然是靜態的故障，那么說明肯定也是硬性故障(系統存在真實問題)。當然，在這種情況下故障碼肯定也是刪除不掉的，因此變速箱起動應急模式切斷了K1離合器的工作，此時奇數檔全部失效而僅保留偶數檔部分。這說明問題將會將會出現在電控系統或者電路上。既然報的故障是變速箱的閥3，那么首要考慮的是與電磁閥3電路相關的。結合維修資料，首先找到這個電磁閥。

Firstly, to understand the fault problem from the literal meaning of the fault code, sub gearbox 1 refers to odd gears. According to the data, valve 3 is the solenoid valve N435 that controls the transmission of power to the K1 clutch in odd gears. Since the nature of the fault is static, it indicates that it is also a hard fault (there is a real problem with the system). Of course, in this situation, the fault code cannot be deleted. Therefore, the emergency mode of the transmission cuts off the operation of the K1 clutch, and all odd gears are disabled while only the even gears are retained. This indicates that the problem will occur in the electronic control system or circuit. Since the reported fault is valve 3 of the gearbox, the primary consideration is related to the circuit of solenoid valve 3. Based on the maintenance information, first locate this solenoid valve.

排放變速箱油拆卸變速箱油底殼，并將機電控制單元總成小心的拆下來，并斷開電磁閥連接的線板。首先利用萬用表對其N435電磁閥本身進行線圈阻值的獨立測試。

Drain the transmission oil, remove the transmission oil pan, carefully disassemble the electromechanical control unit assembly, and disconnect the wire board connected to the solenoid valve. Firstly, use a multimeter to independently test the coil resistance of the N435 solenoid valve itself.

通過萬用表的測量，N435電磁閥在不同溫度下的電阻也在正常范圍內，說明電磁閥本身是好的。然后將線板與變速箱控制單元的插頭拔掉，并把線板的另一端與電磁閥進行連接，從控制單元插頭出處找到N435電磁閥的相關針腳。直接從控制單元輸出端對電磁閥的電阻再次進行測量發現，電阻值變得無窮大，說明問題出在控制單元輸出端至電磁閥之間的線路上。如果電磁閥本身沒有問題，控制單元輸出端值電磁閥間的線路也沒有問題，說明問題在控制單元方面了。

According to the measurement of the multimeter, the resistance of N435 solenoid valve at different temperatures is also within the normal range, indicating that the solenoid valve itself is good. Then unplug the plug between the wiring board and the transmission control unit, and connect the other end of the wiring board to the solenoid valve. Find the relevant pins of the N435 solenoid valve from the control unit plug. Directly measuring the resistance of the solenoid valve from the output terminal of the control unit again, it was found that the resistance value became infinitely large, indicating that the problem lies in the circuit between the output terminal of the control unit and the solenoid valve. If there is no problem with the solenoid valve itself and there is no problem with the wiring between the solenoid valves at the output of the control unit, it indicates that the problem lies with the control unit.

通過這種測量不難發現，問題出在線路板(因為控制單元輸出端至電磁閥間的線路連接直接隱藏在這個線路板里面)。因線路板電阻值的變化，控制單元到N345電磁閥的電流不能形成一個完整的回路，即使發動機沒有運轉，打開點火開關以后，車輛也會有個自檢，也會報有相應的故障碼，這也是為什么故障碼不能刪除的主要原因。

It is not difficult to find through this measurement that the problem lies in the circuit board (because the wiring connection between the control unit output terminal and the solenoid valve is directly hidden inside this circuit board). Due to changes in the resistance value of the circuit board, the current from the control unit to the N345 solenoid valve cannot form a complete circuit. Even if the engine is not running, after turning on the ignition switch, the vehicle will have a self check and report corresponding fault codes. This is also the main reason why fault codes cannot be deleted.