You should start by getting the OBD system scanned for codes. Its possible that the computer has stored a trouble code that would help indicate, and isolate the problem.
If its going into the "ASC mode" then theirs probably a bad, or worn out sensor. The ASC kicks in when it senses loss of traction. If the sensor is bad the computer cant tell whats going on with the wheel and may get false readings.
Check your wiring loom going into the trunk. Their known to fray and cause shorting out issues.