Upgrading auxiliary heater to parking heater VW Touran 2011 TDI

This is a description of how to easily upgrade your auxiliary heater to a parking heater cheaper and better than having to choose the 10' to 12' SEK option of a new car or the 15’ SEK Webasto aftermarket option..

Having three kids required a bigger car and the 7-seat option of a VW Touran fit us perfectly. I found a one year old show room car (10km on the meter) with a nice price. Only thing missing was the parking heater functionality.

Some may argue that Webasto have aftermarket kits that will achieve this, but that is not entirely true. An OEM parking heater will not force you to have an ugly control unit on the dash. An OEM parking heater does not require you to change the fan and temperature settings when parking the car. An OEM parking heater will heat the passenger compartment intelligently, meaning first defrosting the windshield and then heating the car normally. An OEM parking heater will give you the settings menu in the meter array display. An OEM parking heater will give you the ventilation mode during the summer. An OEM parking heater installed according to this guide is also a lot cheaper!

Since the TDI engines in the VW fleet are standard equipped with an auxiliary heater, there is actually not very much to change to get the parking heater functionality. The difference between an auxiliary heater and a parking heater is that the auxiliary heater can only run if the engine is running. It is used to get the engine to working temperature faster, thus minimizing fuel usage and lower emissions. The parking heater will also have this functionality, but it will also include the possibility to pre-heat the engine and the inside of the car which is very useful during the winter. No more icy windows and cold car. It even improves your fuel consumption.

Ok, first I needed to find out what the difference really was. For the Touran it is a Webasto TermoTop V (TT-V) unit. (For newer models it is a TT-VEVO. More details on this can be found further down.) It turns out that the parking heater logic is located on the circuit board in the heater fan housing. The fan housing with the parking heater functionality will set you back around 3000 SEK. The nice thing though is that you do not need to exchange the entire fan housing, just the circuit board, eliminating the need to take out the entire heater from the car.

As much as I tried to be well informed before dismantling the car, it took me 3 "attempts". First, I talked to the VW dealer to find out what version of the fan housing I needed to order. I ordered a 1k0 815 020P fan housing. Disassembling the car to get to the heater is quite easy and does not require any special skills. The heater is located just behind the front bumper in front of the right wheel.

Heater location

Getting the fan housing cover off was a bit fiddly, but you can get it off without taking out the heater.

Heater profile without cover

I unplugged all connectors and removed the fan housing circuit board. (The ETKA parts catalog states that this cannot be done, but it can, so..) Here is the fan housing without the circuit board. This is the fan motor.

Inside the fan housing

Comparing the circuit boards there are some differences between the connectors. The auxiliary heater is to the left, the parking heater to the right.

Connector differences

And here are the circuit boards.

Circuit boards

Circuit boards reverse view

I mounted the parking heater circuit board and immediately ran two issues.

Issue one; the two lower connections are quite different. I will need new connectors for this. Issue two; the fan housing cover will not with the new circuit board.

Cover not fitting

I attached the CAN bus to the new circuit board and one positive thing is that I got the Auxiliary heater menu to show up in the meter array display.

Meter array display

I reversed my operation and fitted all the old things again since I needed more parts. I researched the ETKA catalog and contacted Webasto in search for the needed connectors. During this contact, the Webasto representative told me that the Webasto burner type changed from a TT-V to a TT-VEVO in November of 2010. TT-V has a Venturi burner whereas the TT-VEVO has a vapor disc. The control units are VERY different and the TT-VEVO even requires another fuel pump. My car was manufactured before the switch and I, of course, was given the wrong parts number by the VW dealer, giving me a control unit for the TT-VEVO when I need one for the TT-V.

I ordered a new fan housing, 1k0 815 020K, and a new fan housing cover, 1k0 898 021A. This fan housing was somewhat more expensive, but still in the same range.

The hunt for connectors was still on. I finally found out that AUDI had an 8 pin connector that with some minor plastic modifications would fit one of the new circuit board connectors (4F0 972 708). For the 4-pin connector, I still do not have any part number for it. It came with one of my fan housings. UPDATE: Both connectors can be found here (WTYCZKOLANDIA): 8-pin 4-pin

8-pin connector

4-pin connector

So, I started attempt number two! Disassembled the car, got to the heater, and switched the control unit. It turns out that the pins in the old and new connectors are very different, so it was a somewhat tedious job to remove the old connectors, saving as much cable as possible since they are SHORT. I bought new pin connectors for the connector housings and performed the switch.

I had found some web pages where they explained the pin layout of the TT-V, so I followed them and put it together. I tried starting the heater from the meter array display menu, and after making some noise, it shut off. I assembled the car again and decided to analyze it further another day.

I ended up buying a VCDS cable since I realized that performing adaptation and troubleshooting at a VW dealer would cost me AT LEAST half of the cable price. This is if I only need their help ONCE. And since this is somewhat of a "Hack", I'm not sure how helpful they would be.

Connecting the VCDS cable to the car gave me three sensor errors on the heater. After trying to start it 3 times, is locked itself in failsafe mode. Menu disappeared from the meter array display. This was, however, easily unlocked with VCDS. My conclusion was that the new connectors must have the pin layout all mixed up. I started researching the pin layout and finally got a hold of some up to date Webasto documents to give me the correct pin layout and also measurements of the sensors so I could check their condition.

So after a hot summer not needing the heater (the ventilation mode works just fine anyway!), I made my final attempt. I disassembled my way in to the heater and started measuring the sensors. All were OK, but the pin layouts were 110% wrong. I made the easy switch according to the Webasto documents and reattached the connectors. Through VCDS, I could immediately see that I got the correct values.

So, I performed the line filling procedure in VCDS (no actual line filling was needed since I clamped the fuel line just at the heater connection). I then started the heater from inside VDCS and it started smoking like crazy. Success!


The heater is now working properly!

Now for the final piece of hardware switch. We need to exchange the Climatronic control unit inside the car to get the passenger compartment heating working properly. Also, we want the nifty little parking heater button on the panel, letting us start and stop the heater when the car is turned off. Here is the new control unit mounted. (I got the correct part from a newly demolished VW Passat 2011, 5k0 907 044 EC) These control units cost around 4000 SEK new from the dealer. Finding a used part will probably save you 50% (like it did me..)

Comparison Climatronic unit with and without heater support

The new unit requires some coding/adaption with VCDS and then it's good to go. It even interacts with the RNS-510 unit when starting and stopping the heater.

RNS-510 interaction

The remaining thing for this installation is to have it remote operated, but that is not a priority for us since we manage just using the timers available in the meter array display menu. However, when the heater is exposed, add an extra wire to pin 2 on the upper 8-pin connector. This can then be connected to a remote kit to have the unit remotely started and stopped.

(written and performed in September of 2012, in the Malmö/Lund region. Questions and comments can be sent to anders (a-thingy) vennerstrand (dot) se)


1315787A_Workshop_Manual_Thermo_Top_V_en_WEB.pdf – Has a lot of details and troubleshooting tips on the Webasto TT-V burner. This is where I found the correct pin-out setup.

Heater-explode.pdf – Explode image of the heater and its components (from ETKA)

Heater-parts-sv.pdf – (Swedish) Extract from ELSA WIN on the heater and its parts. This includes the statement that the circuit board and the fan housing are inseparable.

Pinout-skiss-sv.pdf – (Swedish) My drawing of the heater connectors and what is connected where (and some pin details..)

Remove-bumper-sv.pdf – (Swedish) Instruction on how to remove the front bumper of a 2011 Touran.

Webasto Telestart T91R installation

Some time has passed and I have finally raised the money for the remote operation functionality also referred to as Telestart. In my install, I prepared for the remote kit by connection pin 2 on the upper 8-pin connector. The cable has been lying rolled up in the engine compartment for a year and a half. Since the Swedish winter was a bit later than usual, why not get the remote kit installed so we can use it this year.

My first concern was if the CAN High/Low pins on the T91R must be connected or not. I searched forums a lot and found very little info, but some confirmed my thoughts. The T91R communicates on the CAN-bus via the heater, or rather, you can reach the T91R via the heater since the heater is CAN connected and the T91R kit is connected to the heater via W-Bus (Webasto protocol with VW dialect). I ran a VCDS diagnostic on a 2014 VW Passat with factory heater and remote and could confirm that the T91R does not show.

I bought my T91R kit from carsystems.pl (new and with cables) for €199. I also bought an extra remote. The extra remote was apparently not of the same type so there are differences in functionality between them. Fortunately, they were very professional and I had my remote replaced without any issues! Matching kits for my car is the 7N0963513A and the 7N0963513B kits.

Anyway, the kit contains transmitter, mount for the T91 receiver, the T91 receiver, connector with cabling and finally an antenna. I had read that the ideal installation location was by the driver foot well. My biggest concern before starting was how to get the W-Bus cable through the firewall. I got a tip to have it go through the hole for the clutch pedal since the car is fitted with DSG.

I started with removing screws attaching the panels below the steering wheel and unscrewing the fuse holder. While digging down there, I saw the mail wire loom coming through the firewall through a rubber seal. This is where I also want my W-Bus cable to go through. I tried squeezing a “pull-wire” through from the inside, but it was difficult at best. From the engine compartment, you cannot see or access anything unless you remove the battery. But, stubborn as I am, I continued my quest. I found the hole for the clutch pedal and removed the lid. It is right next to the wire loom, so with it removed, I could get the pull-wire through the rubber seal much easier.

Getting through the firewall

In the engine compartment, I pulled the wire behind the upper sound damping panel. It was easy to remove and the cable is held in place by the panel itself.

Engine compartment

Next is the electrical connection. According to ELSAWin the T91R should be connected to fuse 21, but to avoid cutting cables it can easily be installed in a free slot. I chose slot 24. In the picture, it is the right most of the small slots.

Fuse holder - Before install

The kit came prewired with a connector that fits the fuse panel so it is just a matter of getting it in properly.


I struggled a bit here, but that was easy once the pink pin-lock was pulled out.


Once the connector is in place, insert the pin lock again. The back of the fuse panel after installation:

Fuse holder - After install

That was power, now the ground connection. I used one of the panel screw mounts accessible from the side of the dash. Here is much room for the antenna as well so this is where I put it. You can see the tiny bit of wire and the gold connector attached to the lower mounting hole. (The thick cable is the antenna wire)

Ground Connector and Antenna

Then I mounted the T91R receiver in a plastic strut behind the fuse box. It’s a perfect fit. I have it oriented so that the connectors are facing the location where antenna and ground connection is located.

T91R receiver

I put the fuse in selected slot 24 and went to perform coding with VCDS.

New fuse 24

In VCDS you first need to modify the coding for the heater to activate support for T91R (starting through W-Bus). After that, I learned both of my remote senders (key fobs) through VCDS as well. This can be done without VCDS, but is much easier with VCDS. Everything works great! You tend to use the heater more when you have the remote.

(written and performed in January of 2014, in the Malmö/Lund region. Questions and comments can be sent to anders (a-thingy) vennerstrand (dot) se)