Timing Component Alignment Marks: Locations

The procedure for "Checking Camshaft Timing" can be found under Camshaft, Engine Testing and Inspection

The following is taken from " Adjusting camshaft timing (N14)"
Adjustments

Important:
Risk of damage! to chain drive.
To open central bolt, mount special tool 11 9 551 on camshaft.
If the setting gauges cannot be positioned, grip the camshaft with an open-end wrench to release the central bolt.