Calibration Mode
When the PCM shuts down, the motor loses its memory. Therefore a calibration is required every time the ignition is switched on unless the PCM has remained active between ignition off and ignition on, for example electric cooling fan after-run.
Calibration only commences after the engine has started.
The calibration process opens and closes the vanes to find the end stops and range of motion between them. This range of movement is checked and if it is within the specified limits, the cycle is passed. This cycle can take up to 16 seconds.
The software allows for a total of six calibration attempts.
If the first attempt fails, as soon as a position demand exceeds 45%, it will carry out the remaining five attempts, one after the other, until they either pass a calibration or fail all six attempts.
If the vanes pass the third calibration, for example if the vanes thaw out during the first two attempts, the remaining attempts are saved for the rest of the drive cycle.
A 'Calibration Failed Fault' Diagnostic Trouble Code (DTC) will only be stored if the calibration fails from the first until the last attempt.
The vanes will then be commanded to open as much as possible.
If the first calibration passes, then a 'Calibration Failed Fault' DTC cannot be set until the next drive.