Steering wheel buttons stopped working

[mjj50]

Hey there!
I have a 2013 mk7 highline tsi, and have recently had an issue that I need help with.
Last week all electrical controls on the steering wheel stopped working, however, the horn still works.

I'm thinking it could just be a fuse, but the manuals information on fuse location isn't accurate.

Any help/suggestions is greatly appreciated!

Thanks again!

[DV52]

mjj50: hi-bummer about the multi function steering wheel. Of course anything is possible, but I don't believe that the problem is the fuse and here's why:



In the upper part of the picture, I've shown the CAN network schematic for the steering wheel on a m7. Unlike previous version of the golf - where the multifunction steering wheel control unit J453 was previously a LIN slave to the steering column electronics control unit J527, on the Golf mk7, it is connected directly to the CAN Gatway (J533) as a LIN slave.

In the schematic, VW show that the signals from the multifunction steering wheel are, as previously the case, transmitted via the coil connectors and the steering column electronics control unit, but for wiring reasons only. They do not have any effect on functions there.

In the lower part of the picture, I've shown the wiring diagram for just the pertinent parts of your post. I've omitted the wiring for CAN Gateway, the BCM and the airbag control module - because they unnecessarily complicate the wiring diagram and I don't think that these modules are relevant (from your account of the problem).

So a few things to note:

1. It appears that a wiring change happened in November 2013 that altered the fuse position for the steering column module. You have indicated that your vehicle is MY13, but you might refer to the factory sticker to ascertain which side of November 2013 your car was built.
2. But regardless of which fuse position applies on your car - note that the red/white fuse wire effectively supplies the steering module which then also supplies the horn. So if your horn is working OK, then J527 is getting +12volts - so the fuse is OK (I think)
3. Notice also the label KL 30 on pin#10 of the steering column module. This means "terminal 30" and it indicates that the supply voltage to the multifunction module (which controls the multifunction switches) comes via J527.

What I think this means (and I'm guessing) is that your problem might be elsewhere! Perhaps it might be prudent to check the earth connections on the steering wheel and in particular, the integrity of the connections to J453.

But I suspect that your best approach might be to hook-up a diagnostic tool to the car (i.e. OBDeleven, or VCDS, or VCP), because all communications for the multifunction buttons happen over the LIN wire shown in the picture above (i.e. purple/white wire). This being so, a diagnostic tool might be able to pin-point the area of the fault in the report of the "Trouble-code" (I hope)

Don

[Gabriel Guzman]

Hi Don,
I have a similar problem but it is just with the cruise control that is not working properly sothe other buttons are working perfect (Radio functions, vehicle info and horn)

The dealership scanned the car and they found J453 fault so I need to replace the electronics column module and they are not sure if it is the problem. If it is not the problem I need buy an other part


I think that is an electrical problem

do you think that is a good idea take the part from the wreckers?

Gabriel

[DV52]

Gabriel:Hi.

Here's how the buttons are wired to J453:


As you can see- the buttons are wired in clusters (i.e. left/right-side button banks).

Of course, anything is possible - but given the arrangement above, it's difficult to believe that a faulty J453 module could result in only the cruise control button being problematic and "the other buttons are working perfect".

However, and without knowing the results of the dealership scan - I guess it's possible!!

J453 is NOT part of the car's Component Protection regime. So yes - a second-hand (used) module from a wrecker should be OK if the part number is identical (try to source a module with the same software number (best outcome for compatibility).

What you will need to do is to replicate the module database from the old J453 into the new unit. To do this, you will need to extract this database from the old J453 BEFORE removing the module. The extraction process depends on what diagnostic device you are using - so don't forget to do this (makes life a lot easier!!).


Don