1.13.2.1 Monitoring Function - Crankshaft Camshaft Synchronization

P0018 

The diagnosis is executed at every edge of the selected camshaft signal and at the reference gap of the CKP sensor signal. The distance in crankshaft degrees between events is compared to the stored camshaft signal pattern. The distance, plus/minus a tolerance value, needs to fit the designed pattern position for each signal edge. The tolerance is expanded by the range of the variable valve timing when the camshaft is not in lock position.

The following malfunctions are detected:

• CMP sensor signal selected for synchronization invalid: P0018

The monitor eliminates the edges from the list of all six camshaft edges which do not fit the pattern in every case. When a calibrated number of camshaft signal edges is detected and the list of remaining signal edges contains at least one edge, the camshaft signal is valid for synchronization. When no edge is left in the list, synchronization has failed and is re-started. When a calibrated number of synchronizations fail, the error is delivered to the error management. When synchronization fails with the intake camshaft, the same procedure is then started with another camshaft.