Help needed please

Hi guys, desperately need help. I've been a long time lurker and now decided to join up.

I've got an octy 2 1z 2006 tdi vrs, having mega trouble with the rear doors staying locked. I used to have a problem with n/s/r door staying dead locked then as soon as you get it open with the rocker switch in the centre console the o/s/r would deadlock. Never bothered me much until both doors have remained deadlocked now, I've stripped the entire car out to test the voltages and resistances and so far no faults traced to wires.

I work for Vw as a tech so have access to vaspc the only fault it's thrown up is the rocker switch implausible signal. So checked voltage at the wire to it and getting 3v not sure if that's right or not would expect to see 5v or 12v. I don't have access to a current flow diagram so unsure if this switch is causing a problem. The fronts are absolutely fine, work as they should.

I should add the rears have manual windows so its not the ecu for that. Also I have replaced the convenience ecu and tried a new door lock on the n/s/r and its still exactly the same. You can hear the locks bouncing when you press lock and unlock, I am at the end of my tether with it now and need help. Doubting both door locks have failed. Has anybody had a similar fault with their car? Sorry it's so long winded just wanted to describe the fault as accurately as possible over text.