Variable Camshaft Monitoring
11. VARIABLE CAMSHAFT MONITORINGControl deviation of the camshaft position controller
In this diagnosis module the difference between the actual and target position of the VVTI unit is checked.
Description "target":
The target position has to be in a limited stable range. If the actual position is near the target position the diagnosis is ok, otherwise not. This will be checked by calculating two integrals (Reset integral and Failure integral). Both integral values have the same threshold to reach. If the failure integral reaches this threshold the fault processing begins and a fault code (DTC) is stored.
Description "slow response":
The set point and the camshaft position are saved at the beginning of a set point change. If this set point change is big enough (gradient), the camshaft phasing change is evaluated. If the change is smaller than a threshold, a slow response is detected, and if the value is greater, then there is no malfunction. By detecting a malfunction, the fault processing begins and a DTC is stored.
Flowchart - Diagnosis of control deviation of camshaft position controller "target"
Flowchart - Diagnosis of control deviation of camshaft position controller "slow response"
