Solenoid valve power to Volkswagen passat automatic transmission failure

Solenoid valve power to Volkswagen passat automatic transmission malfunction metropolitan Shanghai Volkswagen passat auto YiLiang years admin time model. GSi car, carrying the public AGN s-tronic electronically controlled automatic transmission type, the user reflect the vehicle transmission shift impact of symptoms. After a period of repeated size throttle after commissioning, impact fault block is finally solved. Shanghai Volkswagen passat YiLiang years model. GSi car, carrying the public AGN s-tronic electronically controlled automatic transmission type, the user reflect the vehicle transmission shift impact of symptoms. After car we for the vehicle road test, determine the car transmission exist the following failure (1) into the forward gears and reverse gear. (2) into the power forward gears transmission joint, transmission within long time issued a similar to the sound of friction. (3) serious impact. (4) engine speed and its corresponding speed when the car speeding do not match, obviously feeling engine speed on the high side, feel the lack of a block, should be the hydraulic torque converter lock up clutch working poor. (5) with the increase of speed, the transmission of internal noise it will rise. Based on previous maintenance experience of the transmission and combined with the car's fault phenomenon, maintenance must be carried out on the transmission was dissolved. After decomposing the transmission, carefully check, found the problem in terms of mechanical and hydraulic components (1) N the main hydraulic regulating solenoid valve, N and N shift quality solenoid valve has a problem, leading to the impact and shift impact problems. (2) K dantian drum clutch on a positioning bracket is damaged, the piece on the bottom of the spline can not lead to K with the drum, resulting in brake into forward gears transmission power transmission joint minister within the transmission time issued a similar to the sound of friction. (3) through the visual observation of hydraulic torque converter found appearance, torque converter has been high temperature presents a green blue, we determine the burning of the torque converter lock up clutch. (4) differential and inside due to the lack of the main reducer gear oil lubrication, lead to larger transmission noise. After the replacement of damaged parts and in accordance with the overhaul standard operating, the transmission refitted junior President time road test, other problems are resolved, but against the impact of problems still exist. And there is a phenomenon is special, the smaller the throttle opening shock feeling stronger, if just loose the throttle when blocking point, impact will be more intense feeling, down when the impact is not obvious. Since block impact have direct relationship with the throttle opening, pressure and the transmission system is with the throttle opening increases, so basic can eliminate the problem of internal mechanical transmission components can also rule out the problem of the hydraulic control valve and solenoid valve. Because from the analysis on oil, cover when N solenoid valve power through the clutch oil, K N electric solenoid open/brake oil B, N electromagnetic valve power cut/K block clutch oil; N and K power continued to joint, the N, electromagnetic valve, power is cut off the oil B N oil solenoid valve power through to K. Block is between B and K switch, electromagnetic valve between the switch is the conversion between N and N, N solenoid valve also needs to help maintain shift-are working pressure ( Note solenoid valve are all new parts) , so the question should be out on the control signal. We don't see any problem from the aspects of automatic transmission, therefore, decided to shift the focus of the maintenance to the engine. For this, we observed the dynamic data of engine control system, based on the analysis of the main data under various operating conditions of engine, feel the air flow meter in idle speed numerical some slants big, Engine speed air inflow is when r/min. ~。 g/s) , decided to change the air flow meter. Continue to run after replacing air flow meter, fault, there is no change. Continue to observe the throttle opening, voltage and injection pulse width signal, all normal, but to be on the safe side, we replace a throttle and matching test failure remains. Maintenance are deadlocked at this time. The control unit is out of the question? As is known to all, the self-learning function of the mass M and N are, finished and need to test for a long time to learn. But this car has long road test, the fault has not been ruled out, but can only replace the control unit to try, but still disappointing result. At this time, everyone felt very confused, don't or hydraulic problems? In this case, we have to replace the hydraulic control valve body, at the same time also will replace solenoid wiring harness, but fault symptoms did not change. It's so strange! Is it long test time is not enough? The first day we ran a long drive this car, back problems still exist. At this point, maintenance personnel decisions for the 'big throttle no problem, the smaller the throttle problem' of trouble truck for learning. After a period of repeated size throttle after commissioning, impact fault block is finally solved.