This makes it possible to determine when a valve is sticking.
Monitoring the eccentric shaft positionThe Valvetronic control unit continuously checks whether the actual position of the eccentric shaft corresponds to its set position. If it is not possible to detect the current position, the valves are opened to the maximum without control. The air volume is now restricted by the throttle valve. In the event of a fault occurring, the eccentric shaft is set to maximum possible valve opening. The two signals must not deviate from each other. whether there is a short-circuit or sensor defect. The monitoring function checks whether the voltages are within the permissible range, i.e. Monitoring the signal voltagesThe Valvetronic control unit permanently monitors the two voltage signals of the potentiometers. The Valvetronic control unit powers both potentiometers with a voltage of 5 V. The two signals are sent to the Valvetronic control unit in digital form. For safety reasons, two angle probes with opposing characteristic curves are used. The engine management controls the position by means of the electric drive until the current position corresponds to the set position. The sensor is equipped with two independent angle probes. Position sensingThe current position of the eccentric shaft is sensed by a special position sensor. The Valvetronic control unit evaluates the signals of the position sensor and controls the servomotor of the eccentric shaft. All functions are calculated in the engine control unit. The communication between the engine control unit and Valvetronic control unit is on a separate LoCAN bus. The servomotor is fitted to the cylinder head and it drives the eccentric shaft via a worm drive in the oil chamber of the cylinder head. The variable valve gear is moved by its own control unit and servomotor. The corresponding position of the variable valve gear is calculated in the engine control unit from the position of the accelerator pedal and other variables. For tank ventilation, a certain vacuum is still necessary. In all other operating states, the throttle valve is opened so far that it only has a very slight throttling effect. The throttle valve is now only used for starting up and for emergency operation functions. This produces an adjustable stroke of the valves. An electrically adjustable eccentric shaft uses intermediate levers to change the effect of the camshaft on the rocker arms. The air volume supplied to the engine is not set by the throttle valve but by the variable stroke of the intake valve. Variable valve gear / ValvetronicThe variable valve gear was developed to reduce fuel consumption.
Hope anybody can find this useful.From WDSVariable valve timing gear / Valvetronic*
On my manual car, it is fully drivable with no loss of power (if not more power) with better throttle response. In this mode, the valvetronic opening would be set to 100% and DME will use back the throttle to control the engine.This was done on a locally assembled E46 318i 2002 with N42 engine.Though the valvetronic computer was put into limp mode, there will be no error light on the dash but the status was confirmed with Autologic. The valvetronic is disabled in this case by disconnecting the eccentric shaft sensor, this will put valvetronic function in limp mode home.