[Guide] [T6_modified] T6 Webasto Aux/Parking (water) Heater Configuration with VCDS

[Jey]

Hi,

I'm back in this topic.

MMI, maybe you could help me.

On my engine (Caravelle T6 2016 - 150hp TDI), I already have the DEFA warming system (the 220v heater screwed on the bottom of the engine).
This is "just" warming the bottom of the engine/oil.

I would like to install the DEFA 413708 (220v, it's warming the cooling liquid, going in the engine - I have this on a Honda here in Lapland, the engine is warm...).
Like that the engine and the cooling liquid are already warm.

About this part, on some shop I can read :
"Huom! Moottorin ohjainlaite on päivitettävä uudelleen kun moottorinlämmitin asennetaan autoon, muuta asetus: VW Codification Block 5 from <<43>> to <>taiVW Codification Block 5 from <<63>> to <>Riippuen siitä onko "Block 5" alkuperäinen asetus "43" vai "63"."

In english :
"Note! The engine control unit must be updated again when the engine heater is installed in the car, change the setting: VW Codification Block 5 from <<43>> to < > or VW Codification Block 5 from <<63>> to < > Depending on whether "Block 5" is the original setting " 43" or "63"."

Defa-letkulämmitin #413708 | Motonet Oy

Huom! Moottorin ohjainlaite on päivitettävä uudelleen kun moottorinlämmitin asennetaan autoon, muuta asetus: VW Codification Block 5 from to tai VW Codification Block 5 from to Riippuen siitä onko Block 5 alkuperäinen asetus 43 vai 63.

m.motonet.fi

But few years ago I already changed the settings for the Webasto (first page of this topic).


MMI, do you understand if I can keep the webasto set like currently (warming the cabin + the engine), and the DEFA 413708 ? (Of course, I will not start the webasto if the car is on the 220v).

 

[n10n]

MMI, do you understand if I can keep the webasto set like currently (warming the cabin + the engine), and the DEFA 413708 ? (Of course, I will not start the webasto if the car is on the 220v).

Maybe @mmi will step in with a better answer but I don’t see why not.

I have webasto heating engine+cabin and a separate Defa water heater, installed before my ownership. I think I’ve sometimes even used them at the same time, and certainly never even considered I would need to be careful with the other if one is used. I mostly tend to warm with webasto though - it’s not common I would have 220V connected and webasto running.

 

[Jey]

Thanks.

I ask because I want to be sure that the installation of this Defa water heater will not cancel the settings of the Webasto.

I use my caravelle many times per day during all the winter, plugged at home on the 220v, or in the nature the rest of the time, and here it could be up to -40°c, so I really need to manage well the heating (for the engine, and for the passengers (in tourism activity)).

 

[Jey]

I just received an answer from VW (who will install the Defa water heater soon), that they don't change any setting.

 

[n10n]

Found installation instructions for that heater and it indeed says ECU should be coded for a preheater:

http://old.defa.com/vfp/eh/413708.pdf

Also, my 2018 CXEB ECU indeed has C3 in 5th position (byte 4)

Address 01: Engine (J623-CXEB)       Labels:. 04L-907-309-V2.clb
   Part No SW: 04L 906 056 AF    HW: 04L 907 445 A
   Component: R4 2.0l BTD   H03 6207
   Revision: 23101001  
   Coding: 0025401CC33601080000

 

[mmi]

MMI, do you understand if I can keep the webasto set like currently (warming the cabin + the engine), and the DEFA 413708 ? (Of course, I will not start the webasto if the car is on the 220v).

I ask because I want to be sure that the installation of this Defa water heater will not cancel the settings of the Webasto.

Webasto and Defa live happily together. There is no interference between the systems.

I just received an answer from VW (who will install the Defa water heater soon), that they don't change any setting.

That's interesting. A few years ago (2019) I asked Defa about the reasoning of the coding. Defa's statement was that the coding is from VW Finland. Also was mentioned that T6 from MY19 onwards do not need the coding change.

 

[n10n]

That's interesting. A few years ago (2019) I asked Defa about the reasoning of the coding. Defa's statement was that the coding is from VW Finland. Also was mentioned that T6 from MY19 onwards do not need the coding change.

Would be interesting to know what the coding actually changes.

I can only think it would relax some engine sensor limits in order to avoid error codes in starting - for example, different coolant sensors could have wildly different temperatures. But why same setting would not apply for webasto then?

 

[Jey]

Thanks for your reply!

 

[mmi]

Would be interesting to know what the coding actually changes.

I can only think it would relax some engine sensor limits in order to avoid error codes in starting - for example, different coolant sensors could have wildly different temperatures. But why same setting would not apply for webasto then?

Well, VCDS claims that the bits in that area of the coding alter number of installed electric coolant pumps. I have thought the electric heater also has one. However, T6s with and without Webasto are coded the same - which a kind of suggests Webasto communicates with engine some other way.

I concur that the Defa coding probably affects the accepted tolerances from different coolant sensors. I'm fairly confident the T6 (MY16-18) would report something about implausible coolant temperature when warmed up with electricity. I have been told that some VW passenger cars are especially picky on this coding.

Perhaps something to code differently for the coming winter

Interestingly the "C3" coding is found only T6 scans in Finland

 

[n10n]

Well, VCDS claims that the bits in that area of the coding alter number of installed electric coolant pumps. I have thought the electric heater also has one. However, T6s with and without Webasto are coded the same - which a kind of suggests Webasto communicates with engine some other way.

I as well think Defa has a small pump of it’s own. But Defa is connected just to the mains, not to CAN or any other car electronics so I’ll take that VCDS claim with some salt.

I concur that the Defa coding probably affects the accepted tolerances from different coolant sensors. I'm fairly confident the T6 (MY16-18) would report something about implausible coolant temperature when warmed up with electricity. I have been told that some VW passenger cars are especially picky on this coding.

Perhaps something to code differently for the coming winter

Good thinking, might be a nice test to see if this would trigger any DTC’s

Interestingly the "C3" coding is found only T6 scans in Finland

Oh really? That sounds like we’re guinea pig market for something, it’s not like our climate is all that different to our neighbouring countries…

 

[Jey]

New reply from VW Rovaniemi:

"when 413708 motorwarming install is not necessary doing cooding"

 

[n10n]

New reply from VW Rovaniemi:

"when 413708 motorwarming install is not necessary doing cooding"

Well, they should know, we’re just speculating here

 

[eugene]

Video overview of my install process: