Variable Camshaft Timing
| Item | Description |
|---|---|
| 1 | Variable camshaft timing solenoid, intake camshaft |
| 2 | Intake camshaft VCT solenoid seal |
| 3 | Intake camshaft VCT control valve |
| 4 | VCT unit - intake camshaft |
| 5 | CMP Sensor - intake camshaft |
| 6 | CMP Sensor - exhaust camshaft |
| 7 | VCT unit - exhaust camshaft |
| 8 | Exhaust camshaft VCT control valve |
| 9 | Exhaust camshaft VCT solenoid seal |
| 10 | Variable camshaft timing solenoid, exhaust camshaft |
This is an electro-hydraulically controlled camshaft adjustment system that allows variable timing for the intake and exhaust camshafts independently of each other.
To do this, each camshaft is equipped with a VCT unit. The front closing plates of the units are marked with I (intake) and e (exhaust).
| Item | Description |
|---|---|
| 1 | VCT unit (intake camshaft) |
| 2 | Front closing plate |
| 3 | Rotor |
| 4 | Return spring |
The units have the same basic design. They are equipped with three oil brackets. A return spring is used to reach the closing position.
The difference between the VCT unit intake and exhaust camshafts is in the closing position. The unit of the intake camshaft closes in "retarded" position and the unit of the exhaust camshaft closes in the "advanced" position.
The VCT units are bolted with the associated VCT control valve on the respective camshaft. This means that:
- Securing bolt and control valve form one component.
Both VCT units have a maximum mechanical adjustment angle of 49 degrees crank angle. The maximum programmed adjustment angle is 45 degrees crank angle.
The particular control valve is operated by a VCT solenoid. Both solenoids are secured to the front of the timing case with three securing bolts each.
| Item | Description |
|---|---|
| 1 | Magnetic alignment of the magnetic disk |
| 2 | Signal from CMP sensor |
| 3 | Setting of the camshaft Comments: Figures given in degrees camshaft |
The exact angular position of the intake and exhaust camshaft is each detected by a CMP sensor. The sensor scans a magnetic disk which is shrunk onto the particular camshaft. This signal is changed into a square-wave signal by the built-in converter electronics and sent to the PCM.
Both sensors are mounted from above on the valve cover with one securing bolt.