Battery drain only when doors locked

Anyone have a idea where to start trouble shooting? 2002 Jetta TDI, my battery will completely drain overnight or after 12 hours at work if I lock the doors. Either with the key in the door, the remote, or the button from the passenger door. If I leave it unlocked though no problems. Thank you any input

A volt meter and a schematic and a few minutes work should find the problem for you.

When you lock the car...do you hear the horn beep to signify all doors are locked? If not, maybe one lock actuators is stuck or sticking causing a drain. Just a thought.

There's a factory TSB on how to quickly track down current drains, using a multimeter across the fuses, so you don't wake any sleeping modules and chase red herrings. The old-skool method of pulling all the fuses and measuring the current at each fuse doesn't work as well.

Searching "current drain TSB" or something like that would probably help you find the threads here.

I did check the amp pull using my meter between the battery and the positive cable and all was good. It seems to be intermediate, was hoping someone had this happen before with a quick fix. I'll keep looking thank you

The CAN bus isn't going to sleep, i.e., going into low current standby mode, after a period of inactivity like it should. Something is keeping the CAN bus alive when it should be in sleep mode. Check for one of more broken wires in the wire harness to the driver's door, the usual culprit.

Good luck.

Thanx will go hunting.