Audi A6 (MY17) - Retro Towbar Install
- Thread starter VAG_MAN
- Start date
Hi Uwe / Neil,
This still isn't working. However, when I go to the trailer module 69 and perform an output test for 'trailer hitch indicator light' and 'trailer hitch indicator light 2' the led actually glows up green and red just as it should.
So it works with an output test from the module but not under normal operation.
Do you have any thoughts on this at all?
Anything would help if you could please.
Kind regards
Darren
This still isn't working. However, when I go to the trailer module 69 and perform an output test for 'trailer hitch indicator light' and 'trailer hitch indicator light 2' the led actually glows up green and red just as it should.
So it works with an output test from the module but not under normal operation.
Do you have any thoughts on this at all?
Anything would help if you could please.
Kind regards
Darren
A6 Towbar Retrofit
I have just read through your post and would like to try and help. I have done the exact same retrofit and used a custom harness from a company in Germany. My tow bar came second hand from Germany with the handle bracket but no indicator lamp - I found a suitable LED and wired it up and it worked fine. Looking at the wiring diagram I wonder if your problem is the switch in the towbar itself that might be at fault. Do you have access to the wiring diagram it shows the switch connecting to pins 9, 10 & 11 on the 17 pin connector from the towbar. I am guessing it is a 1 pole changeover switch which will change the indicator. I am not sure if there are any measuring blocks on module 69 showing the status of the switch. Having read the post I am not sure coding of any other module is relevant to the indicator light. My wife is away in the car for a couple of days but I can do more checks later in the week.
I have just read through your post and would like to try and help. I have done the exact same retrofit and used a custom harness from a company in Germany. My tow bar came second hand from Germany with the handle bracket but no indicator lamp - I found a suitable LED and wired it up and it worked fine. Looking at the wiring diagram I wonder if your problem is the switch in the towbar itself that might be at fault. Do you have access to the wiring diagram it shows the switch connecting to pins 9, 10 & 11 on the 17 pin connector from the towbar. I am guessing it is a 1 pole changeover switch which will change the indicator. I am not sure if there are any measuring blocks on module 69 showing the status of the switch. Having read the post I am not sure coding of any other module is relevant to the indicator light. My wife is away in the car for a couple of days but I can do more checks later in the week.
Hi Mike,
Thanks for trying to help. Any suggestions are greatfully received.
I have a wiring diagram and yes you are right there are 3 wires for the switch from the towbar and it had crossed my mind that it's possible the switch in there could be faulty. I'm not sure if there are measuring blocks for the switch in that module but it's a great idea to check for them. I will try and do that tomorrow and report back.
Thanks for trying to help. Any suggestions are greatfully received.
I have a wiring diagram and yes you are right there are 3 wires for the switch from the towbar and it had crossed my mind that it's possible the switch in there could be faulty. I'm not sure if there are measuring blocks for the switch in that module but it's a great idea to check for them. I will try and do that tomorrow and report back.
Hi,
I have clicked on Advanced measuring values and there is the option to measure the 'Trailer hitch indicator light' and 'trailer hitch indicator light 2'.
However, when I tick the boxes to measure them the 'Actual' value is 'Not coded / installed'
Which is leading me to think it still needs coding somewhere or activating possibly?
Im kind of all out of ideas at the moment.
I have clicked on Advanced measuring values and there is the option to measure the 'Trailer hitch indicator light' and 'trailer hitch indicator light 2'.
However, when I tick the boxes to measure them the 'Actual' value is 'Not coded / installed'
Which is leading me to think it still needs coding somewhere or activating possibly?
Im kind of all out of ideas at the moment.
Hi, I'm just about to undertake this on my 2015 post facelift A6 C7 and like Mike I'm going to be using the loom from the Indy German company. I have pre checked my harness and the function of the switch which works like this:
When in either deployed & locked or stored & locked position the switch common is connected to one input and the other input is open circuit. When anywhere in between the one which was open closes and the other opens. Sorry I cannot remember which pin number is which as it was a week ago since I checked it all out. I'll let you know how I get on but it may be a few weeks before the weather warms enough to do this. The only thing I'd say is that if you can get all the other features working like the ASR adapted, reverse lights and parking sensors disabled etc I think I could live without the led on the release working, but I can appreciate your wanting to get it all as per OEM. I'd try too.
Dave
When in either deployed & locked or stored & locked position the switch common is connected to one input and the other input is open circuit. When anywhere in between the one which was open closes and the other opens. Sorry I cannot remember which pin number is which as it was a week ago since I checked it all out. I'll let you know how I get on but it may be a few weeks before the weather warms enough to do this. The only thing I'd say is that if you can get all the other features working like the ASR adapted, reverse lights and parking sensors disabled etc I think I could live without the led on the release working, but I can appreciate your wanting to get it all as per OEM. I'd try too.
Dave
I may have stumbled across a very similar issue with my Q5 towbar install. If i code the towing module following the vcds coding guide i lose the led and indication on the dashboard. If i leave the coding as it was when i got the module from audi parts the led and dashboard indicators work fine. It is acoding issue within 69.
Not sure it's that simple. I tried coding it myself and it didn't work. Audi coded it and it then did but there was no change to module 69. There must be some substance to what you found but I don't think it is the whole answer. Not for an A6 anyhow...?
That's interesting Dave, especially having now read your thread and the coding Audi performed. There must be some interrelation between the various modules and if either one or another is not coded quite right it will cause the issue, but not sufficiently to throw a fault code. In due course I will get my Q5 coded by Audi SVM and see if it changes anything. Hopefully it will not cost much if anything if I get done whilst having a service.