Functional description
To perform the adjustment, the variable camshaft timing control requires a feedback signal on the current position of the camshaft. Camshaft sensors on the intake and exhaust side record the position of the camshafts.
The exhaust camshaft sensor is designed as an inductive hall effect sensor. The camshaft sensor wheel has 6 different flank spacings. The flank spacings are detected by the hall effect sensor.
The engine control system uses these to calculate: here
- Camshaft speed
- Camshaft speed
- Exact position of the camshaft
This graphic shows the N63 engine (contents of brief component description apply in principle to other engines as well).
| Index | Explanation |
|---|---|
| 1 | Cylinder head cover |
| 2 | Exhaust camshaft sensor and intake camshaft sensor |
| 3 | three-pin plug connection |
A controlled VANOS unit is fitted at both intake and exhaust camshafts. A VANOS solenoid valve activates the VANOS unit. The required positions of the intake and exhaust camshafts are calculated from the engine speed and the load signal (depending on the intake air temperature and engine temperature). The DME control unit activates the VANOS unit accordingly. The control of the intake and exhaust camshaft is variable within their maximum adjustment range.
When voltage is applied, it is detected whether the sensor is above a tooth or above a gap.