Transmission Position Sensor/Switch: Description and Operation

Clutch Pedal Position (CPP)/Park-Neutral Position (PNP) Switches

Typical Clutch Pedal Position (CPP)/Park-Neutral Position (PNP) Switches:

The Clutch Pedal Position (CPP) switch is an input to the PCM indicating the clutch pedal position and, in some manual transmission applications, both the clutch pedal engagement position and the gear shift position. The PCM provides a 5-volt reference (VREF) signal to the CPP switch and/or a Park/Neutral Position (PNP) switch (on the CPP signal line). If the CPP switch (either or both CPP and PNP switches are closed) is closed, indicating the clutch pedal is engaged and the shift lever is in the NEUTRAL position, the output voltage (5 volts) from the PCM is grounded through the signal return line to the PCM, and there is 1 volt or less. One volt or less indicates there is a reduced load on the engine. If the CPP switch (or PNP switch on vehicle or both CPP and PNP switches open on the vehicle) is open, meaning the clutch pedal is disengaged (all systems) and the shift lever is not in NEUTRAL position (PNP switch systems), the input on the CPP signal to the PCM will be approximately 5 volts. Then, the 5-volt signal input at the PCM will indicate a load on the engine. The PCM uses the load information in mass air flow and fuel calculations.