Logging: VAG-Com Measuring Blocks Inside

[Arin@APR]

Listed below are common logging blocks in VCDS. The block numbers and names may not be the same for every ECU so feel free to make adjustments to the list. Also feel free to add anything else you find interesting to log!

 21 - Throttle Position	 	 
 24 - Accelerator Position	 	 
 33 - Long Term Fuel Trim Bank 1	 	 
 34 - Long Term Fuel Trim Bank 2	 	 
 35 - Engine Speed
128 - Ambient Pressure	 	 
292 - Timing Retard Cyl 1	 	 
293 - Timing Retard Cyl 2	 	 
294 - Timing Retard Cyl 3	 	 
295 - Timing Retard Cyl 4	 	 
296 - Timing Retard Cyl 5	 	 
297 - Timing Retard Cyl 6	 	 
298 - Ignition Angle	 	 
421 - Mass Air Flow
436 - Boost Pressure (absolute)
632 - Intake Air Temperature	 	 
702 - Boost Control Valve Angle

To log the car:

1. ESP OFF
2. ASR OFF
3. AC OFF
4. Radio OFF
5. Windows Closed
6. VCDS Turbo Mode ON if possible
7. Use 4th Gear
8. Starting RPM 1500 RPM's or lower
9. Finishing RPM 7200 RPM's or fuel cut off/gear shift
10. Put the Accelerator all the way down for the entire run
11. Do not lift the Accelerator before the end of the run
12. Do not enable the kick down switch on S-Tronic vehicles

Here is how you navigate through VCDS and Save Files:


Selecting LOG on the last screen will prompt you to enter a file name before logging.

[primetime]

Arin, Nice! I can only log 12 fields.... What 12? What are we measuring with the 4th gear 1500 to redline? Weather permitting I will try this Wed.

Also, everyone make sure you hit save when it's asks you too.... don't be like me and log 8-1/4 mile passes and not save! DOH....

[Arin@APR]

I only posted this up as a reference. You can log any 12 you like! I just suggest you always log RPM so you can everything against it. :-)

[primetime]

I only posted this up as a reference. You can log any 12 you like! I just suggest you always log RPM so you can everything against it. :-)

Oh ok.... I was wondering what you were trying to measure with the above....

[Arin@APR]

I believe several have asked for measuring blocks in the past so I figured I'd share several. :)

[madmadS4]

wow this isn't at all what I've been doing

[primetime]

wow this isn't at all what I've been doing

Really? What have you done to log?

[rktskicar]

Listed below are common logging blocks in VCDS. The block numbers and names may not be the same for every ECU so feel free to make adjustments to the list. Also feel free to add anything else you find interesting to log!

 21 - Throttle Position	 	 
 24 - Accelerator Position	 	 
 33 - Long Term Fuel Trim Bank 1	 	 
 34 - Long Term Fuel Trim Bank 2	 	 
 35 - Engine Speed
128 - Ambient Pressure	 	 
292 - Timing Retard Cyl 1	 	 
293 - Timing Retard Cyl 2	 	 
294 - Timing Retard Cyl 3	 	 
295 - Timing Retard Cyl 4	 	 
296 - Timing Retard Cyl 5	 	 
297 - Timing Retard Cyl 6	 	 
298 - Ignition Angle	 	 
421 - Mass Air Flow
436 - Boost Pressure (absolute)
632 - Intake Air Temperature	 	 
702 - Boost Control Valve Angle

To log the car:

1. ESP OFF
2. ASR OFF
3. AC OFF
4. Radio OFF
5. Windows Closed
6. VCDS Turbo Mode ON if possible
7. Use 4th Gear
8. Starting RPM 1500 RPM's or lower
9. Finishing RPM 7200 RPM's or fuel cut off/gear shift
10. Put the Accelerator all the way down for the entire run
11. Do not lift the Accelerator before the end of the run
12. Do not enable the kick down switch on S-Tronic vehicles

Here is how you navigate through VCDS and Save Files:


Selecting LOG on the last screen will prompt you to enter a file name before logging.

I do not think you should be logging these in 4th gear till redline. 3rd gear is fine. Be safe!

Bruce

[madmadS4]

I'm clicking OBDII:


Then Mode 1 Read Data:


Then I pick the blocks I want. I can only pick 4, but the list looks more comprehensive than Arin's. Then I'd click the Log button and it'll have a Start button where I can log to a .csv file.





Curiously enough, if I pick Vehicle Speed, I get a new button which pops up. This button is called Acceleration.


This brings up an Acceleration dialogue box - which I haven't yet started playing with. Looks easy to get a 0-60 or a 1/4 mile though. I'll be playing with this next.

[Arin@APR]

I do not think you should be logging these in 4th gear till redline. 3rd gear is fine. Be safe!

Bruce

We suggest 4th gear since the vag-com sample rate is so low. 4th gear will take longer and will give you more sample points in a run.

[OOOO SSSS]

Hi,
Thanks for this. It is most helpful.
Please can you tell me what the "Long Term Fuel Trims" should be.
With my car switched off mine is -7%. I am an ex 2.0T driver, and I know that the tolerances are -10% to +10%. Is this the same for the S4 ?

Thanks in advance.

[OOOO SSSS]

Hi,
Thanks for this. It is most helpful.
Please can you tell me what the "Long Term Fuel Trims" should be.
With my car switched off mine is -7%. I am an ex 2.0T driver, and I know that the tolerances are -10% to +10%. Is this the same for the S4 ?

Thanks in advance.

Anyone, have an idea ??

Thanks

[Keith@APR]

We suggest 4th gear since the vag-com sample rate is so low. 4th gear will take longer and will give you more sample points in a run.

and its also the closest to a one to one between the engine and gearbox so it shows the most correct load on the engine.

[NinjaActionJean]

Bumping one from the dead here. New to logging with my vag-com and this is the type of info i'm looking for except the logging parameters seem to be totally different on my '14 S4 and vcds v12.

For example I cannot find boost pressure in the vast list of logging parameters. Does anyone have any current info on logging in the B8.5? Just got tuned and would like to see some boost pressure info among others.

[NWS4Guy]

Bumping one from the dead here. New to logging with my vag-com and this is the type of info i'm looking for except the logging parameters seem to be totally different on my '14 S4 and vcds v12.

For example I cannot find boost pressure in the vast list of logging parameters. Does anyone have any current info on logging in the B8.5? Just got tuned and would like to see some boost pressure info among others.

Yes the numbers changes for '13 or '14, they are there with different numbers but the same description I believe, you just have to look over all the data points to find them, or look around at newer logging threads on here, I know they have been posted before.

[drob23]

The numbers for some of the parameters have changed significantly, but the names should all be the same. VCDS sorts them alphabetically, but of course *after* sorting by capitalization.

So it goes lowercase -> first character uppercase -> first+second character uppercase etc.

[saxon]

I generally do 3rd gear, do people really do a 4th gear pull on the streets?

[F16HTON]

I generally do 3rd gear, do people really do a 4th gear pull on the streets?

4th on the streets is well in excess of 100MPH. You can create a group with the VCDS (UDS) and then save it. This will allow you to speed load the group at a later date.

[infinkc]

4th on the streets is well in excess of 100MPH. You can create a group with the VCDS (UDS) and then save it. This will allow you to speed load the group at a later date.

hmm, ive never noticed that feature to save the groups. I need to play around with it more, i hate scrolling and selecting all the parameters each time, especially on an 8" tablet.

[NinjaActionJean]

I just went thru the entire menu twice. I cannot find supercharger boost!!! Please, what is the exact name?

[drob23]

Here is what primetime said are the useful signals to log:

logging by sasfasdf, on Flickr

[NWS4Guy]

Yep looks like 184 is what you want for boost, as noted in the above, this is in hPa, so you have to convert it to PSI, then remove ~14.696 for the one atmosphere of pressure we are already under, being around sea level to get the actual boost in PSI.

[NinjaActionJean]

Thanks for that guys. The groups are all different in my car, but using the info posted by drob23 I found what I was looking for.

Just did my 1st log. Not looking good to me but I don't know how to interpret this. To me it looks like lots of knock and Timing pull.

APR 91 Oct Stage 2 tune, stock intake and APR exhaust. Atmospheric pressure was 12.47 psi. Did a pull in 2nd to 7200RPM and pull in 3rd to 7200RPM. Looks like the update time is too slow to get proper results.

[drob23]

I'm no expert with reading logs but it looks like you have a bunch of snap shots, would be better to get a continuum as you rev out. A lot of your timing pulls from knock occur at low RPM, which is surprisingly the easiest situation to create knock (low RPM/high load).

Here is the rest of primetimes email that might help you:

"
OK, so logging is rather simple really... I'll give you the field names and numbers but depending on the version you have and they change frequently when RossTech does updates the numbers may not match so look for the names more so... I'll also put a link from a thread Jspazz made on AZ with pics of how to log but I'll walk you through it as well... Again, it's easy and if you have questions just ask or make a post and others will help also...

When you login choose the following ---> engine controller button ---> advanced measuring values ----> then you'll need to choose the various fields you want to log. You can log up to 12 but the sample rate is slower the more you choose however it is still decent even with 12 so log what you want... A very key step that I'll mention now and later is to choose "Turbo Mode" and also check off the box in the upper left called "Group UDS requests" This will give you the best possible sampling rate... If you don't do either of these the sampling will be very poor so again, it's critical...

Now for fields... When you first log on look for ambient air pressure and select that... Write down the value and then de-select... You'll use this later to convert your hPa boost number to psi if you desire and I'll go over that... Here are the fields I then select while logging... Again, the # of the field may be different but the



Most of the fields are straight forward... accelerator position shows when you are WOT, engine speed is rpm, IGA_AD_KNK are the individual cylinder timing retard values so you can see if timing is being pulled, Ignition angle is your total timing, Air Mass is the volume of air going into the blower, intake manifold pressure is your boost levels in hPa, RFP_AV is your boost bypass valve stated in percent, Intake air temp. is the temp of the intake air, and charge air pressure specified is how much boost the tune is calling for and this is your upper limit so to say... There are many other fields we can go over but these are where you should start and will tell you a ton about the car...

For converting the hPa #'s to psi you take the hPa value and subtract the ambient value you wrote down from it and then multiple that value by .014503774 This is than your boost in psi.

What I do at the track is get everything setup and then I just have to hit start right before I make a pass and then stop right after the pass... Whatever, you do DON'T shut the car down w/o first saving the file otherwise you can potentially lose the file... I usually make a few passes in a row save the file, let the car cool down and repeat. It really depends on how crowded the track is or isn't...

Again, make sure to hit the turbo button and check of the group uds requests box as it's critical and easy to forget...

Here is a good thread that Jspaz put together on vendorzine...

http://www.audizine.com/forum/showth...VCDS-logs-here

"

[NinjaActionJean]

Thx for the info drob23. I'll try to do another session tonight. I did click the turbo mode option, I didn't see a Group uds request box but i
ll look for it next time.

Also, It looks like I'm only getting 13psi boost max. Shouldn't that be 15 with the pulley?

Cheers

[NWS4Guy]

You will and should get some knock detection if it's happening, as well as timing pull to account for and adjust to it. Depending on the climate (humidity and temps) it will also affect boost. You look like you have something earlier than v2.2 for your tune, as there should be ZERO showing for Group 616, that is the bypass valve which should stay 100% closed at all times for any 2.2 or later version of APR, which is one reason you are not seeing higher boost I am sure, the number there is the % open the valve is, and unless you are seeing exceptionally high EGT's, this shouldn't open as it will only open to mitigate problems with temperature on the engine.

[NinjaActionJean]

You will and should get some knock detection if it's happening, as well as timing pull to account for and adjust to it. Depending on the climate (humidity and temps) it will also affect boost. You look like you have something earlier than v2.2 for your tune, as there should be ZERO showing for Group 616, that is the bypass valve which should stay 100% closed at all times for any 2.2 or later version of APR, which is one reason you are not seeing higher boost I am sure, the number there is the % open the valve is, and unless you are seeing exceptionally high EGT's, this shouldn't open as it will only open to mitigate problems with temperature on the engine.

I just had it tuned this week so one would hope they'd put the latest version in. My bypass valve is only open under deceleration(0% throttle). Thats not normal?

[NWS4Guy]

I just had it tuned this week so one would hope they'd put the latest version in. My bypass valve is only open under deceleration(0% throttle). Thats not normal?

Yes, 100% normal, this is done to provide extra engine braking, via recompressing air with the supercharger.

[saxon]

Here is what I normally use, turbo checked with grouping



sent from my s4

[saxon]

4th on the streets is well in excess of 100MPH. You can create a group with the VCDS (UDS) and then save it. This will allow you to speed load the group at a later date.

Can you do a screen shot on how to do that?

sent from my s4