https://docs.emtronaustralia.com.au/engine-management/functions/cam-control/bmw-vanos/index.htmlBMW VANOS Support Early BMW Motorsport VANOS systems were unique. It uses an auxiliary oil pump that boosts operating oil pressure to a constantly regulated 100bar of pressure. The high pressure is used to hydraulically lock the cam position to target during all operating conditions. The design of the system requires two channels per camshaft as there is no default position (ie – Intake retarded position, exhaust advanced position). This means there are separate channels for each camshaft for retard and advance. If the control system is at target, the cams remained hydraulically locked by switching the control system off. Because of the unique mechanical nature of the system, ECU control must be very specific. Emtron has developed a special strategy that mimics the OE function, but allows complete flexibility to enable even more precise control.Hugoen-us