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      06-10-2020, 09:21 AM   #1
mecheng77
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Throttle position in INPA

I noticed when I do a throttle position test in INPA, the actual position
doesn't match what the setting I select.

Attached is a screen shot when I select 99%, it shows 80.1.

Is this normal?
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      06-10-2020, 09:30 AM   #2
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yes, the throttle doesn't actually open to "100%" (5v adc1) - the throttle plate can get jammed.

I pushed it to 85%, but I doubt it makes any difference, it was sized with that factor in mind.
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      06-10-2020, 09:37 AM   #3
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Quote:
Originally Posted by hassmaschine View Post
yes, the throttle doesn't actually open to "100%" (5v adc1) - the throttle plate can get jammed.

I pushed it to 85%, but I doubt it makes any difference, it was sized with that factor in mind.
Thanks, can you clarify what you mean by pushed? You mean programmed or manually?
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      06-10-2020, 10:19 AM   #4
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programmed
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      06-10-2020, 11:10 PM   #5
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Quote:
Originally Posted by mecheng77 View Post
I noticed when I do a throttle position test in INPA, the actual position doesn't match what the setting I select. Attached is a screen shot when I select 99%, it shows 80.1. Is this normal?
I'm interested in knowing:
1) WHY were you doing that Activation?
2) I Trust you were doing the Activation with Ignition ON, Engine OFF?
3) What readings did you see for < F1 > 0% & < F2 > 50% (Both Voltages & % position)?
4) WHAT is your understanding of the Location & Function of the two Sensors whose Voltages you were seeing reported?
5) WHAT is your understanding of the Function of the "Throttle Valve" whose position is being reported?
6) Is nearly 0% near fully-open (Admitting near-max air), or near fully-closed?

This is NOT an attempt to be a "smart-ass". I have tried to find something that discusses the function of the Throttle Valve, both in Bentley & in TIS, and have NOT found anything that describes its function to my satisfaction. The best "Concept" I have been able to obtain is that it is essentially a "Safety Backup" for the VVT system, and it is normally near fully-open position, with Intake Valve Lift controlling "Load"/ Throttle/ or amount of air entering engine, AND the values I have seen when "Monitoring" readout (NOT Over-riding DME Control by pushing F1, F2 or F3) with valve under DME Control, the "Status Drosselklappe/ Throttle Valve % is always in the 2% to 10% range, with the higher % occurring when I press throttle pedal to increase RPM from idle to ~ 3,000 RPM.

The "Throttle Valve" readout is NOT to be confused with Accelerator Pedal Module Position or Voltage signals from its two Pedal Position Sensors, which can be viewed in the attached INPA screens. The first screen (DME > F5 > F2 > F4) shows Ignition On, Engine OFF, Accelerator Pedal nearly floored. Accelerator Pedal Sensor Voltages appear in Left Column, and "Throttle Valve" or Drosselklappe Potentiometer voltages appear in Right Column; Second screen shows data readout, same screen, under same conditions EXCEPT Accelerator Pedal ON Idle position. Third Screen shows DME > F5 > F2 > F6 MWB 6. Data, AT IDLE, includes Throttle Valve Value, and Accelerator Pedal Value, as % of full travel.

I attach a 4th ScreenPrint, the SAME INPA Screen you attach (DME > F6 > F2 > F3 Throttle Valve Control), except mine is once again just Monitoring values with Engine RUNNING, when I have pressed throttle sufficiently to increase RPM to ~3,000. Throttle Valve % = 10.9%

BTW, for anyone following this at Home, do NOT attempt to perform Activation EXCEPT under "Operating Conditions" as shown (in German) at top of screen. In this case RPM = "0" = ZERO = Engine OFF. It's OK to use F6 Activations to simply OBSERVE Readout, but you have to be careful NOT to "Over-ride" DME Control with engine running (UNLESS Operating Conditions allow RPM > 0).

Thanks,
George
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      06-11-2020, 08:05 AM   #6
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I was looking for the wp test and stumbled upon
It. At 50%, it displayed 40%

Good news is that my water pump is still healthy at 130,000km
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      06-11-2020, 09:15 AM   #7
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Yes. it's 0%, 50%, and 100% of the *programmed* value. Since the max is 80, then it being 40 at 50% makes sense. And it probably never actually closes to zero.

As far as how the throttle works, this is only really the basics, but it gives the idea and these are the most important maps.

This is the *mechanical* limits of the throttle opening:


This is the actual min/max TPS setpoint (note that "0%" is really the mechanical limit):


What does the throttle do other than serve as a backup to valvetronic? Well, it can be used to generate vacuum in certain cases, and help with engine startup. Here's the engine start positions based on coolant temp:


Here's the map that is directly referenced in that INPA function (throttle setpoint external adjustment):

There is some hysteresis involved as well, and this map is specifically from a 330i. I assume the 328i is similar.

Here's the throttle mapping based on pedal input (left axis) and maf flow in kg/hr (top axis). This is what directly affects your pedal input, it's multiplied by the c_tps_max values to get the actual throttle position:


Note the left axis scale. It doesn't even start until 53% pedal input, and most of the resolution is from 90-99%. And the top axis is the same, most of the resolution is at low airflow (think about idle, coasting, low speed parking lots, etc), where at high ariflow where you might be cruising down the road, it's mostly open (I don't recall exactly, but I believe the engine flows a lot more than 360kg/hr).

I didn't dig it up but there's also a pedal input voltage vs throttle movement value somewhere, you could use it to make the "throttle" more sensitive or less, but actually that is more related to Valvetronic and the valve opening values, not the throttle itself in a classical sense.

Of course, there are other functions and maps that will determine the final throttle opening, but it gives you the idea.

Last edited by hassmaschine; 06-11-2020 at 09:44 AM..
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      06-11-2020, 09:48 AM   #8
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Quote:
Originally Posted by gbalthrop View Post
BTW, for anyone following this at Home, do NOT attempt to perform Activation EXCEPT under "Operating Conditions" as shown (in German) at top of screen. In this case RPM = "0" = ZERO = Engine OFF. It's OK to use F6 Activations to simply OBSERVE Readout, but you have to be careful NOT to "Over-ride" DME Control with engine running (UNLESS Operating Conditions allow RPM > 0).
actually, I am pretty sure the DME will not even let you activate these tests unless the conditions shown are met. However, it's probably best to not test that theory..
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      11-16-2021, 08:43 PM   #9
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Quote:
Originally Posted by hassmaschine View Post
Yes. it's 0%, 50%, and 100% of the *programmed* value. Since the max is 80, then it being 40 at 50% makes sense. And it probably never actually closes to zero.

As far as how the throttle works, this is only really the basics, but it gives the idea and these are the most important maps.

This is the *mechanical* limits of the throttle opening:


This is the actual min/max TPS setpoint (note that "0%" is really the mechanical limit):


What does the throttle do other than serve as a backup to valvetronic? Well, it can be used to generate vacuum in certain cases, and help with engine startup. Here's the engine start positions based on coolant temp:


Here's the map that is directly referenced in that INPA function (throttle setpoint external adjustment):

There is some hysteresis involved as well, and this map is specifically from a 330i. I assume the 328i is similar.

Here's the throttle mapping based on pedal input (left axis) and maf flow in kg/hr (top axis). This is what directly affects your pedal input, it's multiplied by the c_tps_max values to get the actual throttle position:


Note the left axis scale. It doesn't even start until 53% pedal input, and most of the resolution is from 90-99%. And the top axis is the same, most of the resolution is at low airflow (think about idle, coasting, low speed parking lots, etc), where at high ariflow where you might be cruising down the road, it's mostly open (I don't recall exactly, but I believe the engine flows a lot more than 360kg/hr).

I didn't dig it up but there's also a pedal input voltage vs throttle movement value somewhere, you could use it to make the "throttle" more sensitive or less, but actually that is more related to Valvetronic and the valve opening values, not the throttle itself in a classical sense.

Of course, there are other functions and maps that will determine the final throttle opening, but it gives you the idea.
Damn I wish these images would show. It sounds like you're explaining exactly what I'm trying to understand.

Weirdly when I quoted your text, I can see the image links and can copy paste the link & the images are still hosted!
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      11-16-2021, 10:45 PM   #10
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The images do work, it's because browsers block you from accessing non-HTTPS content on a website that uses HTTPS (this can lead to downgrade attacks). That is a good thing, but I haven't yet been able to update my personal site to use HTTPS.
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      11-17-2021, 07:38 PM   #11
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Quote:
Originally Posted by hassmaschine View Post
The images do work, it's because browsers block you from accessing non-HTTPS content on a website that uses HTTPS (this can lead to downgrade attacks). That is a good thing, but I haven't yet been able to update my personal site to use HTTPS.
Thanks mate!

I was hoping to see the non-linear-ity of the pedal, but this is different.
Great info tho, cheers!
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