continued issues with heated steering wheel install
 

hi
i decided to start a fresh thread on this issue..
2007 D3 originally had 3 spoke sport MFSW with no heat.
i changed wheel , airbag, and steering wheel ecu.
ecu p/n 4E0953549B , replacing original p/n 4E0953549A.
i coded this ecn along with the abs module to complete the ecu install.

the ecu 'sees' the steering wheel heat, and gives no error codes.

the wheel does not ever heat up and i am observing some weird things:
when i push the heat button, sometimes i get '..heat ON' and
other times i get '..heat OFF', and frequently consecutive button
pushes only give me 'OFF' display, even when ambient temp and wheel
temp are cold. i cant seem to figure the logic of the display. owners manual
does not say wheel heat tied to any other criteria (seats, temp etc)

in using the vag com 'advanced measuring block' the following occurs:
-correctly reads the current wheel temp
-the power output stays at 0.0Amp
-always shows the wheel heating in OFF status regardless of dash display.
-in addition, when i do hit the button , the 'heated seats' status reads as activated.
hitting the button does NOT affect the actual heated seats.
nor can i find in which module i can control the heated seats in vag com.
again there are no codes showing a fault in the module.
thanks for any help.
john.

Problem is that you are the most versatile around at the moment. It seems nobody else still on board have any useful experience with this.:(

if thats the case, its a sad state of affairs here lol :)
i am flying pretty blind and no experience except following
some diys and the vcds.

I believe your setup is similar if not the same in general as my Touareg. The trick with the Touaregs in retrofitting the heated steering wheel was actually the clock spring. Once you got the steering wheel module and a heated steering wheel one needed to check their clockspring for the presence of pins in the the connector that plug from the heated steering wheel plugs into on the clockspring. For some reason the clocksprings came without the pins on most touaregs eventhough the ones with pins had identical part numbers.

So I would suggest checking your clockspring as to whether the contact pins are located in the clockspring where you plug your steering wheel into it. Your symptoms sound like that is the most probable case as the coding was accepted meaning you have the right modules but you see no change in current meaning you have no electrical connectivity/flow. I wish I had some pictures of the vw part to illustrate but i don't at the moment.

Let me know if this helps.

Here is an image of the clockspring, I attempted to circle the connector where you plug the heated wheel in. It is hard to see from the image if pins are present but check yours, should be very similar in appearance. Odds are you are missing the pins.

Interesting theory about the clockspring, made sense so I went on to ETKA to find if there are different part numbers and all from 04 to 09 (the latest access I have) show one number only 8E0 953 541 (early production) and 4E0 953 541 (late). So it seems there is only one part number for all cars.

Not sure if there is any type of setting on the heated seat module (or MMI) that would connect to the steering wheel heating module that could be turned on. I only mention it because VAGCOM shows some movement on the measuring block of the seats. Leads to believe that they are somehow connected. Pure speculation here, so tread carefully.

Good luck

If you don't have the pins, you will have no current flow. I retrofitted a heated steering wheel from a non heated steering wheel on my S8, I had to get a replacement clock spring (self cancelling ring) due to the same issue, not having an electrical pass-through on the self cancelling ring for the heat power. The heat power actually goes through a slip ring a brush assembly on the self cancelling ring, where the air bag, digital communications, etc. go through a continuous ribbon cable. That circuit is continuous, the other power circut has a sliding contact.

Pull your wheel again (and myabe the clock spring) and ensure you have connections on both sides. Take a mutli-meter and check continuity through the power connections, check the car side of the self cancelling ring that you have a good ground and 12 VDC to the self cancelling ring, and then check the resistance of the steering wheel heating element to ensure it has continuity and that it is notopen circuited.

Good luck....sounds like the issue will be easy to troubleshoot, especially if you are good with a multi-meter.

Do you have the Bently wiring diagrams? This would be very helpful.

guys,
thanks very much for the feedback.

i did suspect the clockspring as it was
the hardware go-between from wheel to module.
just was hoping it wasnt the case.
i will look again at the bentley cd to see whats what.
i believe i have seen the diagram with the location
of the appropriate pins in that socket.
if diagnosed as such, is it possible to install
the pins in the clockspring or does a new part need
to be sourced? as tashakes indicates, it doesnt seem
clear what p/n would match. i dont want to bust the damn thing.

re the vagcom response to the heated seats
i am still confused as there is no info that says heated wheel is
tied to the heated seats, and other than in module 16 (steering wheel),
i cant find a reference to the heated seats in vagcom either.
and why would heated seats show as 'activated' when i press
heated wheel button, but nothing from vag when i manipulate
the heated seats controls themselves?
ive searched thru almost all the modules to find the seats.

again thanks to all :)

Call the dealer and find out if there are multiple self cancelling rings. They will tell you right away. Or take the wheel off and post pictures of the self cancelling ring. On the D2, it was three wires on the wheel side and two wires on the body side. My old self cancelling ring had the plastic molded, but nothing (no pins) installed. I would not be surprised if this is your case.

checked two dealers, local guy couldnt even look up the part
without a specific VIN, so as i didnt have a donor car VIN with
the heated wheel he could not get a part number.
jim ellis whom i bought from before, was better, but they claimed
only one part number for all a8/s8 of this vintage.
oh well going on vaca next week and will wait til i return
to get back at it. cheers all.