[Guide] [T6_modified] T6 Speedo Adjustment with VCDS

[bullracing]

Mine is a 2016 t32 150 Shuttle.
The values were the sames as on the first post.
I have tyres 245/65/17 so I need to be around the 2300mm circumferance.
Is there a way to up this value or do I have to just select the nearest target value which is 2298mm?

 

[Big.mac]

Just reading through this thread now and I wonder if the differences between the two sets of options available are linked to the chassis type. The T6 comes in a 16” or 17”chassis. The 17” chassis has the larger brake callipers etc and it is not possible to fit 16” wheels to it. That’s might explain why there are the 3 ‘out of range’ options? The 16” chassis can obviously take the 16” wheels. If i understand correctly, not all vans with 17” wheels as standard have a 17” chassis and there will be vans that have has 17’s fitted aftermarket as they are readily available with people selling Devonports etc when they upgrade.

 

[mmi]

Mine is a 2016 t32 150 Shuttle.
The values were the sames as on the first post.
I have tyres 245/65/17 so I need to be around the 2300mm circumferance.
Is there a way to up this value or do I have to just select the nearest target value which is 2298mm?

The wheel circumference is just an approximate value in table of the Instrument cluster. To get "exact" correction is better use the delta percentage - relative to factory size, e.g

So only thing that can be changed is the long coding, the rest have been fixed.

 

[bullracing]

Ok brill thank you. So I am not far off at all. Testing at 75mph on the speedo I am doing 70mph so maybe I should knock it down to number 2 option instead of number 1 to bring me even closer to 10%.

Mine is indeed a 16" chassis. Just out of interest, Can I change the coding to a 17" chassis?

 

[mmi]

Hmmm... if I got this right - currently (small tyres) your speedo shows 75 mph when true speed is 70 mph, thus overreading 75/70 => +7.1%

Bigger tyres would cause speedo show -10.3% less than now. So if would like to keep the "safety margin" - speedo reading having the same offset as now, then setting 2 is probably the closest one.

However, if would like to have "true speed" reading on the speedo, setting 7 - corrects speedo to read +2.2% more than now. In addition to that you already have +7.1% "offset" from factory setup and then -10.3% from bigger wheels. All these would make speedo read -0.8% = less than actual speed - probably not a good thing. Setting 4 would give +3.0% offset (on safe side).

I haven't look if there is a coding for different chassis - yet

 

[bullracing]

Hi MMI. Sorry thats me not explaining properly. With the big tyres, I have already changed to setting 1 and I am now getting 75mph on speedo but gps is 70mph.
So I can probably leave as is now and keep that safety margin there.

 

[russters]

OK I just did this on my Van,

On the VCDS Coding Helper Page mine lists the original setting as 04 Distance impulse number 4 - VW Polo(6R)
IDE00842 K-Number 22740
IDE00845 Wheel circ. 2111mm

when I changed it to 05 Distance impulse number 5 - Amarok (2H)
IDE00842 K-Number 23232
IDE00845 Wheel circ. 2066mm

 

[YannMcHaggis]

Sorry to resurrect an old thread, just wanted to add a couple of things here.

Firstly, a massive thanks to the OP for this info, it is extremely helpful! I'm going to be switching out my tiny 16" wheels for 18"s soon and will need to recode the speedo, this info is exactly what I was after.

Secondly, has anyone got a link to a tyre calculator which matches the VW circumference values? All the ones I've tried so far give different results. I'm using the 215/60R17 = 2111mm as my benchmark for this. All the calcs I've tried come back around 2166m. It sounds like there are calculators out there that do match up with the VW numbers, so please let me know if you know of one!

 

[Big Al]

You will probably get a different value on every on-line Tyre circumference calculator. Chalk mark on floor and matching on the side wall, drive 1 revolution, measure the distance from each point will give you a ball park figure. Doing more revoloutions and dividing by the number of revolutions will make the calculation a bit more accurate. Or take it to a Tachograph centre and put it on rolling road for an accurate `L`Factor.

 

[lexc]

When I changed from OEM wheels to 235/65/17 aside from the speedo under reading by about 10km/h at 100 I also noticed the DSG shift points were no longer ideal, felt like it was shifting too early, depending on where the gearbox got its wheel speed signal from, I was hoping this would fix it.

After a short test drive, things do feel a lot better, but I've not yet done enough km to say for certain. It's likely I was just stomping it the last few drives prior and it adapted to that.

Can anyone else confirm the DSG seeming happier after correcting this?

Distance impulse number 1 was the ticket, the vehicle now over reads by about ~7km/h at 100 which is basically the stock delta.

 

[Andysmee]

MY19 here and it is set to K-number 5 by the factory (it's a trendline so on steel wheels).

I'm now on 255/40 R20 which is 3.81% difference. Any ideas what setting I should use or at least try?

 

[mmi]

MY19 here and it is set to K-number 5 by the factory (it's a trendline so on steel wheels).

I'm now on 255/40 R20 which is 3.81% difference. Any ideas what setting I should use or at least try?

It looks like that available settings in your van are different than the two setups presented in the first post.

Unless you exctract full table, the best guess is to change K-number (coding) just from 5 to 4. Most likely it changes the speedo to read somewhat more. Just read IDE00842 (=K-number in Adv. Measuring Values) before and after the change - they will give the exact correction achieved.

 

[Andysmee]

It looks like that available settings in your van are different than the two setups presented in the first post.

Unless you exctract full table, the best guess is to change K-number (coding) just from 5 to 4. Most likely it changes the speedo to read somewhat more. Just read IDE00842 (=K-number in Adv. Measuring Values) before and after the change - they will give the exact correction achieved.

K	K-number	Wheel circumference	%
6/7/8	Could not be coded	-	-
5	23232	81.339" / 2066mm	0 (factory)
4	22740	83.110" / 2111mm	2.18
3	21868	86.417" / 2195mm	6.24
2	21106 (? or 21100)	89.567" / 2275mm	10.11
1	20384	92.171" / 2341mm	13.99

 

[BigDean]

Hi all, can you use Carista to change this setting, or must it be VCDS?

Its the only change I need to make, and want to do it the simplest way.....

Thanks
Dean

 

[Andysmee]

I did mine with an OBDEleven, not sure about Carista.

Update on mine, at setting 4 with my 255/40R20 it's almost exactly as per GPS, so I'll nudge it to 3, as I'd prefer to be showing faster, not accurate. Can't recalibrate my brain after 30-odd years of driving!

 

[BigDean]

Thanks to @Loz, now updated. Just in case it helps anyone, mine is a T6.1 T28 110. Changed from standard wheels to 17" Black Rhino Arsenals with BFG 245/65/17s.

It was reading 10% under, so actual speed of 30 would display as 27 on the dash. Dangerous....

Reading the thread above, it looked like we needed to change the coding from 6 to 2. Not only was it already set on 1, when trying to change to 2, it would not accept it.

So, we tried to set it to 6, which it accepted, and is now perfect! Also looks like it may have solved the ACC errors I was getting. None so far afterwards.

Thanks again @Loz

 

[Desmoben]

Thanks to @Loz, now updated. Just in case it helps anyone, mine is a T6.1 T28 110. Changed from standard wheels to 17" Black Rhino Arsenals with BFG 245/65/17s.

It was reading 10% under, so actual speed of 30 would display as 27 on the dash. Dangerous....

Reading the thread above, it looked like we needed to change the coding from 6 to 2. Not only was it already set on 1, when trying to change to 2, it would not accept it.

So, we tried to set it to 6, which it accepted, and is now perfect! Also looks like it may have solved the ACC errors I was getting. None so far afterwards.

Thanks again @Loz

This is good news for me I think. I’ve a T6.1 t30 shod with 245/65R17’s too. Also having ACC error at anything over 117kmph on the speedo. Below this it works perfectly fine ???
Hoping to have mine recoded on Monday coming - your data will help tremendously

 

[Stoatie_weasel]

 

[Lightrofit]

@Andysmee

I'm also using OBD11, tried adjusting the speedo error last week.

I adjusted "wheel circ." onder control unit 17 Dashboard.

I was on version 3, i selected version 8, all saved fine.

Tested it, it's off, so i tried resetting to original and/or something else.

But it won't let me change it anymore. keep getting errors "(22) Function cancelled., marginal conditions have not been met"

Any ideas?

Greetings
Leo

Did a solution get found for this to change it back?

 

[mmi]

nope untill today it's stuck in 'version 8' , car has been in the dealer with 'neutral sensor' issues, next week they will replace the entire gear shaft. maybe when these errors are fixed I can alter that setting?

It's T6.1?
Could you please post the actual coding of 17-Instruments before and after the tweak. Also software identifiers would be helpful.
E.g. this section of a scan

17 Dashboard​

System description: KOMBI ​

Software number: 7LA920741 ​

Software version: 6750​

Hardware number: 7LA920741 ​

Hardware version: 204​

ODX name: EV_DashBoardVDDMQBAB​

ODX version: 009069​

Faults:​

No trouble codes found​