The APP (accelerator pedal position) sensor comprises two separate sensors.
If one of the two APP sensors fails, then only a proportion of the engine's power will be available when accelerating. Top speed can nevertheless be achieved.
If both of the APP sensors fail, the engine is regulated to a defined speed following a plausibility check after the BPP (brake pedal position) switch and brake light switch have been actuated once.
The vehicle can then only be accelerated to a defined speed.
In either case, a fault is saved in the error memory of the PCM.