My 2006 Jetta had a hidden auxiliary heater, and it cost me $.25 to enable it
I got my 2006 2007 Wolfsburg Jetta from Copart. I noticed that it seemed to have an auxiliary heater layout, so I looked into it further. Sure enough it had an auxilairy heater.
But the configuration label on the hood was coded no auxilary heater.
Well I checked with Auburn Volkswagen, Auburn Washington, and they speculated that all it needed was an adaptation.
And they were right!
A friend with VCDS adapted it, and I spent about USD$.25 to stuff a fuse into fuse slot #11, and now I have heat after 45 seconds. And though it is not hot enough to wear a tank top in the car, the aux heater, coupled with the very effective seat heater, keeps me comfortable in Seattle traffic.
auxiliary heater aux heater auxillary heater cabin heater auxilliary heater
Here are some random notes from this TDI Forum about aux heaters :
I heard about the Aux Heater after posting about my "8" mile warmup.
Seems that in some cars the Central Electronics Controller (09) has a bit to enable/disable it set in the disabled setting. Mine was set to 0, changing it to 1 gave me the morning HEAT.
BYTE 04, BIT 0
If this was posted before I missed it. I was up late last night reading the manual (insomnia). For the 2006 I saw on Book 3.2 Page 80 the fuse box numbers. Fuse box A 15, 25 and 47 are for "Auxiliary heating*" so if you pop open the fuse box you should be able to see if you're wired for aux heating or not.
Added for clarity: There are 2 controllers label Aux Heater. The controller labeled "18 Aux Heater" is the controller I activated by mistake and got the fault code because what it controls is not installed on N/A cars.
Anyway, if you go to the installed controllers tab in VCDS, the last controller, on that tab, which is called "7D Aux heater" is the controller you want for measuring. Measuring block 1 has info on the Z-35 element which is the element installed in the N/A TDI's.
I tested this with VCDS and found Z-35 to be drawing about 635 watts till the coolant temp turned off the controller. I will have to wait for the car to cool down to figure out what else the other measuring blocks tell me.
Below is lifted from an old post. If you do a search for "Aux heater" in only the A5 threads, there is a ton of info in the older threads.
There is some confusion about the Aux heater. There is a controller called [18] Auxiliary Heater. That is not the controller that commands the Aux heater on and off. [18] Auxiliary Heater is for an option NA cars don't have.
On the A5 and probably the later cars, the Aux heater is identified as Z35. Look in the the controllers for a measuring block called Z35 Auxiliary Heater. Once you find it, the controller it resides in controls the Aux heater.
Address 7D: Aux. Heat
Part No SW: 1K0 963 235 E HW: 1K0 963 235 E
Component: PTC-Element 0404
No fault code found.
End
For output info: 7D Aux. Heater -> Measuring blocks
For enabling bit: 09 Cent. Elec. -> Coding -> Long Coding -> Byte 4 Bit 0 or 1 (I believe 0 is for Webasto, 1 is for PTC, but do not quote me on that).
