[thstone]

Aha! I found the exact conditions:

When the ignition is switched on, the electromagnetic valves of the camshaft adjusters are supplied with positive potential. If the engine is started, the control unit applies ground to terminal 25 (camshaft adjuster for cylinder line 4 - 6) and to terminal 52 (camshaft adjuster for cylinder line 1 - 3) if the following conditions are fulfilled (VarioCam activated);
1 - Engine oil temperature between -3°C and 133°C
2 - Engine speed > 1,300 rpm
3 - Throttle opening > 5%
or
1 - Engine oil temperature > 133°C
2 - Engine speed > 1,480 rpm
3 - Throttle opening > 3.9%

Variocam is deactivated by the DME control unit if: engine speed > 5,120 rpm"