Throttle position sensor acting very weird.

[Jkha]

Hey! I have an a4 b8 2008. I recently got check engine light for P2100 and P0122.

after a good read on different forums, i ended up replacing the full throttle body as a solution. This included the relearning sequence etc.
for the time being i have no check lights, so that’s good. But on my OBDII reader i look at ‘throttle position’ as a guideline to how the swap is doing.

This is showing 84.5% at idle. When i push the pedal it goes down to an appropriate level  (equivalent of the amount pushed down on the pedal) but when i release, it goes back up to 84.5%.

So what i’m asking here is, are these normal values? As I presume the flap is moving as it should following the numbers when pressed. To me it seems like an electronic issue with the brain or some other sensor.
Any thoughts about this?

thanks in advance! 
Sincerely Jon

Edited 4 hours ago by Jkha

[Stevey Y]

13 minutes ago, Jkha said:

Hey! I have an a4 b8 2008. I recently got check engine light for P2100 and P0122.

after a good read on different forums, i ended up replacing the full throttle body as a solution. This included the relearning sequence etc.
for the time being i have no check lights, so that’s good. But on my OBDII reader i look at ‘throttle position’ as a guideline to how the swap is doing.

This is showing 84.5% at idle. When i push the pedal it goes down to an appropriate level  (equivalent of the amount pushed down on the pedal) but when i release, it goes back up to 84.5%.

So what i’m asking here is, are these normal values? As I presume the flap is moving as it should following the numbers when pressed. To me it seems like an electronic issue with the brain or some other sensor.
Any thoughts about this?

thanks in advance! 
Sincerely Jon

Hi it could well be the throttle position sensor on the pedal it should be showing about 23% at idle.

Steve.

[Jkha]

That’s what i’m thinking. But as it functions normally while driving, im not sure if it’s worth doing over some idle numbers. But can it be changed by itself? Or does the whole pedal assembly need to be replaced.

[Stevey Y]

12 minutes ago, Jkha said:

That’s what i’m thinking. But as it functions normally while driving, im not sure if it’s worth doing over some idle numbers. But can it be changed by itself? Or does the whole pedal assembly need to be replaced.

Hi it is from memory not part of the pedal but its attached to the side of it, but if you are not that bothered by it leave it until it breaks then replace it.

Steve.

[Jkha]

After looking around i found nothing under 100$ that fit my car. As it breaks, will the check engine reapper i assume? I havent tested long enough for it to be certain.

because code P0122 is the sensor itself. Could there be a possibility that the whole problem only is the sensor? As P2100 is a following fault related to the sensor?🤔

cause i can possibly return the throttle body, and replace the sensor.

ty!

[Jkha]

After looking around i found nothing under 100$ that fit my car. As it breaks, will the check engine reapper i assume? I havent tested long enough for it to be certain.

because code P0122 is the sensor itself. Could there be a possibility that the whole problem only is the sensor? As P2100 is a following fault related to the sensor?🤔

cause i can possibly return the throttle body, and replace the sensor.

ty!

[Stevey Y]

7 minutes ago, Jkha said:

After looking around i found nothing under 100$ that fit my car. As it breaks, will the check engine reapper i assume? I havent tested long enough for it to be certain.

because code P0122 is the sensor itself. Could there be a possibility that the whole problem only is the sensor? As P2100 is a following fault related to the sensor?🤔

cause i can possibly return the throttle body, and replace the sensor.

ty!

Hi the sticky throttle valve will cause strain on the pedal sensor and quite possibly fry its location discs I normally replace both items when one goes, IE the throttle body they generally wear as a set, if you were looking to buy a car thats cheap to repair you have unfortunately bought an Audi which will never be cheap to fix even the old ones, if you stick a new sensor on with the old throttle it will most likely kill the new sensor in record time, no part has an infinite life/milage span and often as not you have to bite the bullet and just replace the parts.

Steve.

[Jkha]

I see, then i’ll look into changing it. I see used parts from wrecks go for a very nice price in my area. As long !Removed! all parts are functioning as they should i dont think that will be a problem? 🙂

thanks so much for all feedback. happy to see such good responses on a forum! Will most likely ask more stupid questions in the futue😅