We have a 2016 Touran, Europe modell. I had an issue half a year ago, that the tailgate lock did not open, only for a couple of attempts on pressing the button on the key. They repaired as a warranty repair, and it was working fine for a while, but now it's acting up again.
Issues:
  • Even if the car has been opened, e.g. the car stopped and all the doors are open, you cannot open the trunk
  • Using the car open button (the one that opens all the locks) doesn't work at all.
  • You have to keep pressing the trunk lock button for couple of seconds until it clicks and you can open the door
  • And even then sometimes it just opens "halfway" and you cannot fully open the tailgate
  • Once you shut the tailgate, it locks and you have to do the trick with the tailgate button again to get it opened

The car is not under warranty anymore, so I bought a new tailgate lock assembly and replaced the existing one.
The issue is still the same.

Using a Bluetooth ODB2 scanner and a free iOS app Car Scanner, the only trouble code that the system gave was:
09. Onboard supply control unit (this the term that the app used)
203016
Status: Test failed, Confirmed
I could not find anything on the internet for this, I'm not even sure if this is a real error code or not...

Any ideas?

Thanks!