Fehler in den Drosselklappenpotentiometern

A fault in the sensors reporting the throttle plate's position, as distinct from the sensors on the accelerator pedal. Both appear on the same throttle actuator control codes and they are different parts in different places — this pair is on the throttle body, reporting where the plate actually is.

They are doubled for safety and checked against each other. Two sensors track the same shaft with deliberately different output characteristics — often one rising as the other falls — so the module can detect a single sensor drifting rather than believing it. A correlation code is that check failing, and it means the two no longer agree, not that either is necessarily wrong.

Wear at the idle position is the classic failure. A potentiometer-type sensor spends most of its life at one point of its track, which wears there, so the signal becomes noisy or dropped out at small openings while the rest of the range is fine. Watch both signals through a slow sweep — a dropout or step in one while the other moves smoothly names the faulty sensor. Most modern throttle bodies are a sealed assembly, so the sensors are not separately replaceable, which makes proving the fault before ordering worthwhile.