Hi guys I come here with same problem 156 SW 2002 V6 with VDC, got c1205 - front left sensor, wiring error, changed ABS sensor as what I thought it could damage somehow, but it didn't help much.
The only thing that changed was error is disappearing after shuting off and switiching on car, this didn't happen on old sensor.
After some diagnosis I've done with friend and FES we came up to probably dirty magnetic ring, I came back home and cleaned it didn't help, error stoped disappearing.
Today in morning error disappeared, I went to wash and error popped up after it, lights of traction and abs didn't go out, came back home, shutted off car, switched again to igniton and poof lights went out...
I measured continuity from main connector from ABS controller, this short connection between sensor and controller is ok (sprayed clean also connector on pins) sensor is new, now I am thinking about changing bearing to have new magnetic ring....
any of you have found direct problem?
Also about voltage it doesn't drop below 11V (there's about 11.30 V with igniton on) alternator isn't too good but it holds charging on about 13.7-14.2V (it jumps, got another alternator will be renewing it and then fitting to car)