Symptom:
    A 2009 FAW-Volkswagen MAGOTAN 2.0TSI sedan, equipped with a direct shift DSG transmission. According to the user to reflect the car at the start of the occasional refueling engine idling does not take the phenomenon of waiting for traffic lights after the start sometimes fault will appear, sometimes in the normal driving when the acceleration occurs, there is no law failure, The gear indicator on the meter is red and blinks.
    Check analysis:
    First use the fault diagnosis instrument VAS5052A into the gateway check, the control unit are no fault code storage. Combined with the car's fault phenomenon, in view of the fact that the engine response is good, you can initially determine the engine is working properly. Because the car mileage is very short, if the transmission mechanical transmission part is not unusual, the cause of the engine stall can be basically attributed to the transmission clutch was cut off, or the clutch itself has a mechanical failure. The transmission electronic control system provides monitoring of the clutch cut-off data through the data stream 02-08-64 Group 1, which reads 63 times the power off of the clutch and the normal value should be 0, which clearly indicates that the clutch is protective Cut off.
    According to the control principle of the DSG transmission, the clutch circuit is usually caused by the following reasons: the circuit fault of the direct control system is recognized or triggered to protect the cut off function; the oil temperature sensor triggers the protection cut when the temperature exceeds the working limit; When the oil pressure is too high, the corresponding mechanical power transmission assembly is cut off by the mechanical mechanical pressure control valve N233 (N371) and the joint safety spool. In view of the fact that there is no clear fault code display, electronic control components or line directness of the open / short circuit causes the possibility of failure can be ruled out. For safety control solenoid valves N233 and N317, they are control valves that control half of the mechanical parts of the transmission (transmission section 1 and drive section 2) and allow safety when there is a safety fault or if the clutch operating pressure is too large It is noteworthy that the hydraulic cutoff in these two states is generally one of the transmission section 1 or the transmission section 2, and at this time, even if the partial drive is cut off, it is not necessary Will cause the engine is similar to the N block in the idle stall state, Moreover, in many practical circumstances will trigger the activation of the emergency function, and this case is not consistent with the fault phenomenon.