Accelerator Pedal Position (APP) Sensor
WARNING: This page is about a different car, the 2012 Ford F550 Super Duty and 2012 Ford F450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The APP sensor is part of the accelerator pedal assembly. The APP detects the position of the accelerator pedal and inputs this information as a voltage signal to the PCM. The PCM uses APP sensor information in determining line pressure, shift scheduling and TCC operation. Failure of this sensor will cause the transmission to operate at high line pressure to avoid damage to the transmission. This high line pressure causes harsh upshifts and harsh engagements.