Clutch Pedal Position (CPP) Switch
WARNING: This page does not describe the selected car, but rather 25 other vehicles, including the 2013 Lincoln Navigator, 2013 Lincoln MKZ, 2013 Lincoln MKX, 2013 Lincoln MKT, and 2013 Lincoln MKS. However, it is still accessible from the selected car via links, so may be relevant.
The CPP switch is an input to the PCM indicating the clutch pedal position. The PCM provides a low current voltage on the CPP circuit. When the CPP switch is closed, this voltage is pulled low through the signal return (SIGRTN) circuit. The CPP input to the PCM is used to detect a reduction in engine load. The PCM uses the load information for mass airflow and fuel calculations.