What is the name of a sensor behind the transmission and it's function

Over drive lamp fails. I guess or is it flashing for errors.
the service manual covers all that , buy it and read ?
problems with 4R70e transmission , not told. clearly
scanning the PCM now is what is best done.
any time a transmission like this fails to shift the PCM tells you why or how it was detected. via what. with DTC codes
why not scan it.?

OD function. real name is 4th gear is overdriven
so if the tranny stops at 3rd gear we say 4th gear is dead.
4th gear is 0.70: 1 ratio.
engine spins 3/4 turn(near) and drive shift goes 1 full turn
as in overdriven gear.
now lets talk dead 4th gear, all the ways it can happen
sadly lots. for sure you not scanning the PCM first to see why.
speed sensors lie
transmission sensor shows overheating,
engine load is too high. 4th gear makes that worse so why wreck clutch packs doing that and it sure does not.
learn the transmissions are shifted by speed and loads.
load on the engine if tops.
VSS errors, OSS errors
and more, even a weak engine, is a cause.
sorry but this is how it all works
and you can not fix modern cars and trucks lacking a good scan tool..

2.8L USA car? not told country
look here yet?
https://eautorepair.net/Marketing/Default.asp

engine pressure not transmission;.
the cluster lamp lies to you. that? some cars have 2, on for lamp and other for VVT !
it is switch and most cars it turns on below 7psi.
lamp K3 and switch F1 is its name. (German spec names)
older engine its on top front (facing engine) cam shaft cover)
some Audi dealers show the parts list with all parts show graphically
best is try there first, then buy the service manual and find it.
name (yes OEM audi sites some do not show it)
Engine Oil Pressure Switch. OIL PRESSURE SENDING UNIT. OIL TEMPERATURE SENDING UNIT. Part Number: #06A919081J ask here on real forums Audi

some have 2, a switch and sensor oil pressure.
1 just behind the oil filter mount.
and one near cam (top right bank facing bank)

https://www.audiworld.com/forums/a6-s6-c5-platform-discussion-7/oil-temperature-sensor-location-99-2-8l-2763857/

post there, is best. pure AUDI there.

on old cars, not told, fully you, if a/t or m/t box, auto or stick?
but on cars the sensor is named VSS, and is on tail of transmission output shaft ,.
on newer cars with ABS , abs 4 sensors are used at 4 wheels.
no engine told or transmission there.
no vin told.

vss is speed of axles turned by the transmission and is never ever and input shaft. sensor.

we can not see under your hood or behind the flywheel, at all
in the blind.
the SM shows it has 3 pins VSS so is not ABS
has power to it so is HALL sensors (very reliable)
if you scan the PCM (USA onlY) It will tell you it is bad if is.
PCM uses it, and cluster and cruise box. all 3.
sm qoutes
4 cylinder engine automatic.

Disconnect the Vehicle Speed Sensor (VSS) wiring harness. The VSS is located on the rear of the transaxle case near the cooler line inlet.

no engine told not told is an automatic,
me not tossing coin 4 times sorry

The transmission needs inputs from the sensors on the engine, like the manifold pressure sensor, throttle position sensor, temperature sensor and others to function correctly .

The one if front is the input speed sensor. The one behind is out put speed sensor. What was the code?

2nd post same as first then posts displacement.
ok
so its the
3.0 L 4JX1 TD I4

so its a turbo, right, kinda forgot that?
matters...
then fails to post a photo, we are blind lacking a photos
and there are what 10gillion CELL phones now with cameras.
not a rare thing, today... its every where.

is it 4wd
is the sensor on the automatic trans or on the transfer case.
we cant guess that either..????
or is it a stick. ??????????? main trans....

You'll find the sensor behind the firewall on the axle. To replace it, use a jack to raise the car and reach the sensor (on the driver's side). Remember to drain out the transmission fluid before you begin.

Hi.

The vehicle speed sensor or VSS is located on top of the transmission, on the output shaft. This sensor provides input to the speedometer on instrument cluster. There are also 4 wheel speed sensors (one on each wheel). Their primary function is to detect wheel speed to control ABS.

Below a picture of the VSS sensor:

Hello cactus83: My name is Roger and I will help you. You did not say which sensor you wanted to replace. There are two different crankshaft sensors on your car. The 7x sensor is located mid block facing the transmission or firewall side of the motor. Will be held in by one bolt. The 24x sensor is located at the timing cover. Bolts to the timing cover with two bolts. Located behind the harmonic balancer. Should you need further help please just ask. Please rate the answer you received. Thank You for using Fix Ya. Roger

It is located on the front of the transmission. you will see 2 of them one on the left under small transmission lines it is the input then to the right behind the radiator overflow there is the other one. Easiest way to change them is with a 1" deep well socket