Gear Output Side: What is it for?

hello!
Recently, I happened to notice that there's a sensor mounted on the left side of the transmission output shaft, near the driveshaft. Unfortunately, I can't easily access it again without a lift. If I could, I'd disconnect it and check for any error codes using VAGCOM. Perhaps someone here can tell me what this sensor is for and explain its purpose. It's a mystery to me at the moment. I'm wondering why another sensor is needed besides the crankshaft (KW) and camshaft (NW) sensors.
The only thing I can imagine is that the sensor acts as a "speed-based gait recognition" system for the cruise control.
It is definitely NOT the switch for the reverse lights.
The vehicle is a Polo 1.4 TDI PD, manufactured in June 2000.

Best regards,
Dirk.

Hello,

Could it be that you have discovered the speed controller?
Please unplug it and check what your speedometer displays on the next trip.

Best regards, Rainer.

hello rainer!
I was just thinking the same thing, but unfortunately, I couldn't delete the post because you were too fast! So, does the speedometer not get its speed information from the ABS control unit and its sensors (average value?)?
Unfortunately, I can't remove it because I can't reach it without a platform.

Dirk.

Hello Dirk,

brezelmann01 wrote:

... So, does the speedometer not receive its speed information from the ABS control unit and its sensors (an average value, perhaps?)? ...

At least that's the case with my car, although it would technically be possible.
"You could probably save on the sensor here, since the wheel speeds are already known from the ABS system."

Best regards, Rainer.

Rainer K. wrote:

Here, the sensor could certainly be saved, as the wheel speeds are already known from the ABS system.

Hi Rainer,

I would think so too, but which wheel should one engage (for cornering, spinning out, etc.)

It's likely that the engineers are struggling to display an average value from all four wheels on the speedometer.

Or does any law require the speedometer to be a "self-contained system"?
Because otherwise, the excuses used by speeders could be expanded to include the claim "I didn't have a speedometer reading due to ABS problems," which would make them practically irrefutable and could reduce an important source of state revenue.