B6 Passat Towing

[passatpout]

OK, here's the scenario:

I towed the boat from Melbourne to Echuca (and return), all up about 450km of towing.

I'd rewired the boat lights, with new lights, new cable where needed, and IP65 rated junction boxes. Attached it to the car, tested, everything fine.

After about 5 minutes of driving each time, the warning light regarding trailer lights comes up, and the next time I turn the ignition on (is that the right term with a diesel?), warning messages come up, alternatively telling me:

"Trailer brake lights not functional".
"Trailer tail lights not functional"
"Trailer left hand tail light not functional".

So this has left me with a couple of questions:

How is the 12 (or 13)-pin VW plug wired? Does it have a separate feed for both sides of the tail lights, with only the RH one used with the 7-pin converter?

Why would it intermittently come up, after verifying that the trailer lights are working and without breaking any connections?

Is it worth taking it back to the dealer to get checked out?

Nothing that I thought was too bad, just annoying to have the light on when not needed, and reducing the chances of actually picking up a genuine fault.

[rotelman]

Hey Passatpout,

I just got my passat last week. I have the VW installed Tow bar. I towed my Bike trailer last weekend. Worked fine without any problems. I'm in Melbourne so if you wanted to try out a different trailer send me a PM and we can hook up.

Whilst having the trailer on last weekend I discovered that the electric tail gate wont operate at all. I took it to VW where I bought it, after some phone calls and discussions behind closed doors, I was subsequently told that this is a "Safety Feature".. Safety for what? I asked. I said that I was not happy with this response and have asked them to contact VW Germany to find a solution. The only way I can open the tail gate is to force it open manually or un plug the trailer!
The other thing I noted was that the reverse sensors should turn off when the car is hooked up to a trailer....welll so you would think??

Anyone with a E tail gate and tow bar with the same problem?

Rotelman.

[passatpout]

Oh yeah, that was the other thing.. it didn't turn off the reverse sensors when the trailer was plugged in.. good fun going up and down a boat ramp (can't see the trailer without the boat on it, so lots of to-and-fro-ing), having to hit the button every time.

I'm a bit miffed about it, for the cost of the bar you'd expect it to be hunky-dory.. but having checked out Euro wiring diagrams, they do feed both side tail lights independently, and if the adaptor here only feeds from one side, it'll fault every time.

[vanDub]

The other thing I noted was that the reverse sensors should turn off when the car is hooked up to a trailer....welll so you would think??

Can't help with the auto tailgate issue as I have a sedan but the reverse sensor turning off only applies to "factory fitted towbars" ie the european ones. Our towbars and associated electrics are "dealer fitted' and are essentially after market items made by Best Bars in NZ. The sensors don't turn off when the trailer is connected but you can do it manually via the button on centre consol.

What is the ball download on the boat/trailer assembly and how did the Passat handle it?

I am curious as the Passat supposedly has a 85Kg download limit (90Kg in the supplement but my supplement only applies to 103Kw diesel). I can understand part of their reasoning as the rear sinks down markedly with rear seat passengers or a load in the boot (10 bags of pool salt had the rear mudflaps scrapping 98% of the time)

[tryingavw]

I am curious as the Passat supposedly has a 85Kg download limit (90Kg in the supplement but my supplement only applies to 103Kw diesel). I can understand part of their reasoning as the rear sinks down markedly with rear seat passengers or a load in the boot (10 bags of pool salt had the rear mudflaps scrapping 98% of the time)

don't these cars have auto levelling rear suspension?

[passatpout]

Can't help with the auto tailgate issue as I have a sedan but the reverse sensor turning off only applies to "factory fitted towbars" ie the european ones. Our towbars and associated electrics are "dealer fitted' and are essentially after market items made by Best Bars in NZ. The sensors don't turn off when the trailer is connected but you can do it manually via the button on centre consol.

Well, I'm going to let them know that for $1500 I'm expecting something with a few more smarts in it. Besides, if it's not factory fitted for trailer wiring, then why would it still have a Euro-style round 13-pin plug on the car?

What is the ball download on the boat/trailer assembly and how did the Passat handle it?

It's quite light - total mass of boat and trailer would be around 400kg loaded, and it's balanced just slightly towards the front, so estimate ball download of ~45kg. Was just enough to notice the load on the towbar pushing the rear suspension down when first hitched up. More suspension play when the boot was loaded up with suitcases, clothes, etc.

One day I'll take the car and trailer to my local friendly weighbridge and do total mass as well as download on the jockey wheel.

I am curious as the Passat supposedly has a 85Kg download limit (90Kg in the supplement but my supplement only applies to 103Kw diesel). I can understand part of their reasoning as the rear sinks down markedly with rear seat passengers or a load in the boot (10 bags of pool salt had the rear mudflaps scrapping 98% of the time)

I'm guessing the reason for the low download limit is to keep the front wheels on the ground. The more they lift off, the less adhesion and the more likely they are to spin. The effect of the ball download in lifting the front wheels increases the greater the distance between the rear axle centreline and the tow ball centreline, and it's a fair distance from axle to towbar on a Passat wagon.

[MrBean]

Passatpout,

You are right about keeping the front wheels on the ground. I have 1400kg boat/trailer and last week changed my Commodore Berlina for a new Passat 125kw wagon with a dealer fitted towbar. Generally it's ok towing the boat except for standing starts which have to be slow and gentle otherwise the front wheels just spin due to loss of traction. I have looked into this and was advised to fit a load leveller but there is waring in the handbook not to do this. I therefore intend to move the trailer axle to reduce weight on the hitch. Another option is fitting air bladders inside the rear coil springs but these have to be inflated when towing and deflated when not towing - a pain in the a*se.

I find reversing down a boat ramp easier than with the commodore as I just reverse with the tailgate open an can see everything.

I have the same problem with warning lights re trailer lights and would be intersted in possible solutions.

[Caddyman]

Hi, I have a dealer fitted towbar(bestbars) and the reverse sensors turn off when a trailer is connected, it even comes up with a grey picture of a trailer a frame on the reverse camera screen. And my auto tailgate won't open when it is connected, you can open it manually then.

Matthew

[PA.]

Rear Parking Sensors should automatically turn off when the trailer plug is in. Front still works.

Power Tailgate should not work by default as there would be a possibility that the trailer may be in the way. By making you get out of the car and manually open it would reduce the chance of damage occurring as the tailgate crashes into your Jockey Wheel or Boat Winch. I know my old boat trailer winch would foul the rear door on my Subaru.

Seem to remember there may be an option in the MFD to turn on/off the rear sensors when the trailer plug is in.

[Umai Naa!!]

For those whose rear parking sensors aren't turning off with the trailer attached, have the dealer rectify this. They've not programmed the whole shooting match correctly when they've fitted the trailer electrics.

In regards to the lights issue, nine times out of ten, it's a fault in the trailer's wiring. Also, if you're using LED lights on your trailer, that will also cause issues.

As for the auto tailgate, if the trailer plug is connected, or the reverse sensors have picked up something, it will not open. It's no different to Eos roofs not working when an object is within range of the reverse sensors. It's just a safety limitation.

[passatpout]

For what it's worth, I towed the boat for another 300km or so a couple of weeks ago.. only towards the end of one trip (after about 130km) did any warning light come on, but no error messages on the MFD.

Trailer lights are properly wired and connected - made up by myself, using incandescent globes, and checked when I used to conveniently work with an auto sparky.

Still get the reverse beepers going on when the trailer is connected.

[scoutau]

Non disconection of reversing sensors

I have a MY2011 Skoda Octavia Scout fitted with a factory harness.

On most recent European cars (Well VW, Skoda, Audi and Seat.) since 2002, Pin 12 on the trailer or caravan unit being towed must be linked to Pin 3 (Earth return pins 1-8.) in thetrailer plug as it is used as a plug coupling indicator to tell the car it has a trailer connected when plugged into the 13 pin vehicle socket, this will disable the reversing sensors, disable the vehicle rear fog lights in preference to the trailer / van fitted ones and will also sound the vehicle alarm if the trailer connector is unplugged from the vehicle when the vehicle is locked. Some also disable the vehicle reversing lights and electric release tailgates and also tells the vehicle to activate its Trailer Stability Program and Adaptive Cruise Control as well.

This link must be done in the 13 pin Euro to 7 pin adapter lead that is supplied with all genuine kits sourced out of VAG (Best Bars nz towbar and VAG genuine wiring kit.)

The vehicle should have the 13 pin Euro mounted to the vehicle rear apron and the adapter in with the spare tyre in the boot. It should only be plugged in when towing as it disables or enables varied things. I am now contemplating re-wiring my trailer to the 13 pin Euro and having an adapter to 7 pin flat Aus to tow it on other cars! Easier as well as full bulb check on trailer lights as well is a bonus. Utilux Australia carries both Plug and Socket in the 13 pin Euro style as well as Ebay. http://www.vanline.com.au/VPDF/Trailer%20Connectors.pdf

The onboard vehicle CANbus ECU must be told that a towbar is fitted and must be coded correctly. Most problems are fixed when "Australia" is selected as location instead of "Rest of the World" under country in towbar (65) when coded by VAG VAS VCDS
The reason I know this is my system was dealer fitted last week when I took delivery of the new car and they didn’t set it up properly, plugged the adapter in then tucked the 13 pin plug and socket (Minus its waterproof shroud!) under the bumper apron and screwed the 7 pin flat to the apron! I now have to tell them that they need to follow the correct procedures when installing and to rectify it now. Well it was the dealerships second car sold and the first where genuine accessories had to be fitted but still.
Cheers.

[passatpout]

Thanks for the tips..

Like you, I'm thinking about rewiring the trailer to suit the 13-pin Euro.. but I was thinking about putting a junction box on there, and having 2 inputs (one to allow a standard 7-pin flat, the other the Euro), and being able to secure the one not in use. Built properly, it could also act as a dummy load so LED trailer lights would work properly as well. It would be handy for me to be able to put a power outlet onto a box trailer, and leave my camp fridge in there while travelling. At worst, a diode on the respective cables should minimise inadvertent energisation... Any joy being able to source appropriate 12 (or 13) core cable in Australia??

Anyhow, I've checked out my adaptor, and there's no lead between pins 12 and 3, so I'll have to put a bridging link between the 2. I'm sure I have some suitable wire around somewhere...

Also contacted Vanline, the price for the plugs is a little higher than I was expecting (about $20), but no big dramas.. was thinking of picking a couple of them up next time I'm in Sydney, which is now looking like late January. Also makes me feel a bit more secure, since I was always a little worried about losing or damaging the adaptor and being forced to spend a fortune on a new one.

[scoutau]

Well after havingmy scout in at the dealers for a week working out the bad install and making them talk, serious like, to VAG technical, I have some answers as well as my car back. In the Genuine VAG/Skoda electronics cabling kit I have fitted, which is EEA 600 002C E4, the black control box is made by Hella (Saw it on the box myself, along with VAG car symbols and genine VAG part numbers.). Upon discussion with VAG technical, it was found that the towbar electrics where not coded in at/correctly: Yes the trailer lights would work but no bulb detection, rear sensor disconnection etc would work.

I have yet to see if the reversing lights and rear fog will not work on the car but work on the trailer as my trailer isn't here at the moment and like you, I have to get a 13 pin Euro connector for the trailer as it currently has a 12 pin flat connector (This is available from stockists of Utilux parts, truck spare parts.). This may not happen as rear lighting for trailer is also set by entering country code in the lighting section which gives Australian cars 2 rear reversing lights instead of the 1 given in Europe/England which on the opposite side to the single rear foglight. What does worry me is that the VAG supplied 13 pin to 7 pin adapter has the 13 pin Euro pin 2 blue wire (Rear Fog Light.) wired to the electric brake pin on the 7 pin Aus Socket! Could be interesting!

The VAG system detects the trailer fitted by passing a small current down the lighting circuits to see if a loop is connected back by the earth in the trailer connection! VAG doesn't use the loop in it's current wiring kits, so as long as the genuine electrics are fitted, the loop on pin 12 to pin 3 is not needed.

To utilise the charging and other facilities you need the "Constant Plus extension kit for the 13 pin socket" Part number ZGB 000 055 200 w. (This kit is suitable for: VW Passat B6limousine, Variant & Coupe, Passat B7, Touran, Golf V+V1, Golf Variant, Golf Plus, Jetta A5 & A6, Tiguan, Sharan (7N), Skoda Octavia II, Skoda Superb 3T, Seat Leon 1P, Alhambra (7N) ) The reason is that the VAG kit is missing the 3 connections for the 3 pins in the socket, you mayneed to check your socket as mine is missing those 3 pins altogether but the vehicle fusebox is factory fused up for the option and a 3 pin socket off a rear loom is there for the extension kit in factory prep for towing.

I'll check with the supplier of the 13 pin connector as the 12 and 13 wire cable is used on trucks for trailer wiring for special use. When talking to VAG customer care they did tellme that a special "LED load box" was available as a VAG accessory part that would mount on a trailer to allow LED lighting to be used on the trailer, give em a ring for the part number, wouldn't hurt. I thought of the dual tails on the trailer as well but am more down the line of a reverse adapter for the trailer, 7 pin Plug to 13 pin Euro

Let us know how you go. I will do the same.
Cheers

[passatpout]

The VAG system detects the trailer fitted by passing a small current down the lighting circuits to see if a loop is connected back by the earth in the trailer connection! VAG doesn't use the loop in it's current wiring kits, so as long as the genuine electrics are fitted, the loop on pin 12 to pin 3 is not needed.

As far as I can tell, mine has the genuine electronics fitted, but I'll have a closer look on the weekend. It could also be a case of not having the country set right - which I should get the dealer to check now that it's up for its next service.

To utilise the charging and other facilities you need the "Constant Plus extension kit for the 13 pin socket" Part number ZGB 000 055 200 w. (This kit is suitable for: VW Passat B6limousine, Variant & Coupe, Passat B7, Touran, Golf V+V1, Golf Variant, Golf Plus, Jetta A5 & A6, Tiguan, Sharan (7N), Skoda Octavia II, Skoda Superb 3T, Seat Leon 1P, Alhambra (7N) ) The reason is that the VAG kit is missing the 3 connections for the 3 pins in the socket, you mayneed to check your socket as mine is missing those 3 pins altogether but the vehicle fusebox is factory fused up for the option and a 3 pin socket off a rear loom is there for the extension kit in factory prep for towing.

I'll check that out as well. The other option is to run an extension cord from the boot outlet - for the number of times I can see myself using the fridge on the trailer, that would probably work reasonably well. My fridge draws about 6.5A, so it's not overly sucking the juice down.

I'll check with the supplier of the 13 pin connector as the 12 and 13 wire cable is used on trucks for trailer wiring for special use. When talking to VAG customer care they did tellme that a special "LED load box" was available as a VAG accessory part that would mount on a trailer to allow LED lighting to be used on the trailer, give em a ring for the part number, wouldn't hurt. I thought of the dual tails on the trailer as well but am more down the line of a reverse adapter for the trailer, 7 pin Plug to 13 pin Euro

Let us know how you go. I will do the same.
Cheers

I checked with Vanline - they can't supply the cable, and weren't able to point out anyone who could. I'm going to call an auto sparky I used to work with and see what he knows, he's fairly cluey about most stuff that's available and if worse came to worst, he could probably order it for me cheaper than I could get it myself. The other reason I was thinking about making up my own dummy load box is because VW quoted me over $200 (although I reckon they should have supplied it), and I'd probably go for 3 at worst case - one for each trailer I have, plus a spare in case of hiring/borrowing one. The adaptor might be easier as well, since it wouldn't be often that they'd be towed by other cars.

Anyhow, will keep you posted how I go..

Cheers..