Throttle Pot Vagcom Readings

[waad_uk]

Hi all,

Finally got round to using Vagcom with a co-pilot working the laptop.

Whilst out on a run, I asked him to watch the Throttle Switch measuring block to look out for 10100 (WOT). Although I was getting 98.6° on the throttle angle no WOT code. Strangely, we did see it pop up once when I was backing the throttle off to slow down, but Vagcom was playing up a bit by this point!

I have seen a post saying that this angle may not be in degrees and could actually be a %age. Any more news on this?

I would like to check the pot with a meter tonight, but cant seem to get onto s2central? Does the ecu rely on the voltage it sees from the pot, or the resistance, and what are the values I should be hitting at WOT.

[s2dude]

Hi all,

Finally got round to using Vagcom with a co-pilot working the laptop.

Whilst out on a run, I asked him to watch the Throttle Switch measuring block to look out for 10100 (WOT). Although I was get 98.6° on the throttle angle no WOT code. Strangely, we did see it pop up once when I was backing the throttle off to slow down, but Vagcom was playing up a bit by this point!

I have seen a post saying that this angle may not be in degrees and could actually be a %age. Any more news on this?

I would like to check the pot with a meter tonight, but cant seem to get onto s2central? Does the ecu rely on the voltage it sees from the pot, or the resistance, and what are the values I should be hitting at WOT.

I thought Vagcom measured the throttle angle as a %age but I could be wrong.

Try this regarding measuring it

http://www.s2forum.com/forum/showthread.php?t=19183

[waad_uk]

Here is a log taken during a brief run. I have plotted the throttle position (See key on graph) against the engine speed. As you can see, none of it really ties up. There are several instances where the revs are increasing and the throttle position shows over run?!?

WOT was reached twice when decelerating!

[waad_uk]

OK, just done the TPS measurements as described on s2central....

On the Loom:-
Pins 1+2 = 4.96v OK
Pins 2+3 = 4.96v OK

On the TPS
Pins 1+2 = 1890 ohms OK
Pins 2+3 = 954 ohms (Shut) OK
Pins 2+3 = 2570 ohms (WOT) Should be about 3600

The WOT doesnt seem to hit the spec.....

[rj scotty]

They never do mines the same but from what I've read it's not a problem the voltage is far more important.

Hope that helps.

[waad_uk]

yeah I read that as well. So why is the ecu getting in such a muddle with the throttle positions?

[rj scotty]

Only thing I can suggest is:

Get an analogue multimeter put on resistance range, hook it up and make sure the needle rises and falls smoothly.

Or a loose/poor connection but this would seam unlikely

To be fair I've never tried playing with pot on vagcom, ill give it a go the weekend and let you know what mine has to say for its self.

cheers

rich

[waad_uk]

Cheers Rich, that would be great if you could...

I will put the meter on the TPS whilst it is all connected up and measure the output voltage. Does anyone know what the voltage should be for WOT?

[rj scotty]

There was a post on hear some time ago about this exact subject might be worth having a look for that.

[waad_uk]

OK, read back the volatge across Pins 2 and 3 whilst all connected to the car and ignition on.

I get .369v at idle, and 4.59 at WOT. Is this 4.59 too low?

[S2central.net]

Measure the voltage across 2&3 and verify that the transition from idle to WOT is nice and smooth.

[waad_uk]

Hi Paul, just tried with an analogue meter, and the transition is smooth.

Is there a delay issue when reading the measuring blocks that produced the above graph?

[rj scotty]

Audi could have solved this by fitting a an open throttle switch or would that have been to simple.

Got called out today so still did not have a play with vagcom.

sorry

[waad_uk]

No worries Rich

[S2central.net]

@waad - your graph is kinda weird - hard to translate without the raw data - can you send me some raw datalog captures that include RPM, throttle angle and the throttle position flags (idle, part, wot, overrun). As a VAGCOM user you'll know what groups to log... If you can annotate the raw data with any info telling us when you had full throttle then its a big help. You can attach a .CSV file to a post.


Paul