Dear K.Somkid,
Please follow data to OA line because 2 case recurrence detail as following;
Press assembling line is responsible for counter measure must latest
FC.OK: 2015.05.25
DF20AEL
Problem : neutral switch is loose it can not start engine.
We need its all in today. (1,2,3 and add 1,2) in-charge of OA
1.FC/Rework result.
2.The latest operation standard to tighten this nut.
3.Sampling torque check result.
In any way, apply more countermeasure as follows.
1.Add pen check after applying its torque.
2.Add a double check process by another operator