[Teapot]

Hi got a new tow bar fitted and software update done by local fitter witter

After towing for a while the lane assist came up deactivated which affects the front assist and the acc

Back to tow bar fitter they have checked over reset software and still nothing. Waiting on a witter tech for help

Booked in a vw who will also check it over

Can anyone give me some pointers to what could be wrong

Is it down to the tow bar ? Or is it just a coincidence?

 

[fka]

This is completely anecdotal but someone made a comment recently on a thread I started on the Caravan Club forum about towing with a Treg on air suspension or steel springs. I started it before I bought my T5.
The poster's comment was about his Treg on coil springs and rear end sag. Sagging to the point that it lifted the nose of the car so much the front radar is out of tolerance and as a consequence ACC is disabled.
Like I said it's anecdotal. I personally found it hard to believe a trailer with a 100kg tongue weight would make a Treg sag that much..

 

[Henry11]

The nose weight must have been crazy! I’ve loaded the boot up on my coils, and the car doesn’t move

 

[Henry11]

Teapot, you can get a deactivation on the front sensors caused by something simple like a bug splat, I have had it on other VW’s caused by heavy drizzle or heavy rain.

 

[NoobyT]

Which Touareg, what year, Teapot?

 

[fka]

The nose weight must have been crazy! I've loaded the boot up on my coils, and the car doesn't move

My reply is something along the lines that something must be wrong with his car! However I've come across a few other posts talking about rear end sag on the T3, T4 and T5.
Maybe there is something to it. Faulty batches of springs??

If it's ok to post a link to another forum??.. see deepblue1's post
https://www.caravanclub.co.uk/club-together/discussions/information-technical-tips-advice/towcars-towing/vw-touareg-mk3-2018-on-standard-coil-springs/?p=3

 

[Teapot]

It's a 2018 Touareg on standard suspension

The nose weight was 50kg and put the back of the car down a bit

It's a witter towbar and it was recoded when fitted

No bug splat on the badge

I tow a Adria Alpina Colorado which have a long hitch much longer than standard caravans.

I think I've done everything right. I've read everything I can on google.

I can only think that once the dealer recalibrate and I'll ask them to check the software for towing that if I manually switch off lane assist every time I start the car then this shouldn't happen again when I'm towing.

 

[Teapot]

How do you add a picture I want to show you the cat with the caravan on the back

 

[Teapot]

My reply is something along the lines that something must be wrong with his car! However I've come across a few other posts talking about rear end sag on the T3, T4 and T5.
Maybe there is something to it. Faulty batches of springs??

If it's ok to post a link to another forum??.. see deepblue1's post
https://www.caravanclub.co.uk/club-together/discussions/information-technical-tips-advice/towcars-towing/vw-touareg-mk3-2018-on-standard-coil-springs/?p=3

That's a good read and is pretty much the same as my car but steering still feels assured.

 

[Teapot]

Picture attached

 

[Andrewgrale]

When I bought my 06 Panzer, I thought the back end looked like a dog preparing to poop ???? so I borrowed a friends ramp and got in under it, to discover that the last coil of the left hand rear spring was broken top and bottom and the right spring was broken at the top!

Pair of new springs and it's sitting quite normal ????

 

[fka]

Picture attached View attachment 35530

That's quite a lot of squat for a 50kg tongue weight. Did you have much in the boot?
I think now I can see what the guy on the Caravan Club forum was talking about with a 100kg on the tow ball.
Worrying considering the owners manual states you should tow with a nose weight as close to the max 140kg as possible. God knows how much it would squat with 140kg on the hitch!

Personally I disable Lane Assist every time I get in the car. Left it on once by mistake when towing and it was horrible.
However, I don't think disabling it will stop ACC and front assist from shutting down IF the issue is the angle of the radar being raised too high. They all use data from the same set of sensors.
As your squat isn't too bad maybe a dealer recalibration of the radar is possible? Beyond that you're looking at assister springs or airbags to level it up.

This is fairly major balls up and interesting that it's an issue on both your softer SE and the stiffer R-Line springs

 

[fka]

By the way - nice van! I do like an Adria ..

 

[Teapot]

I had 4 dogs in the boot

I'm going to speak to a company today with regards to what I can do to stiffen the rear up a bit.

 

[Black Grouse]

There does seem to be something unusual about T5 noseweight limits - on ClubTouareg the Aussies have noted that the maximum tongueweight (aka noseweight) reduces substantially as the car is loaded, with full tongueweight only available with no rear passengers and no rear load.

 

[hunterlees]

I had 4 dogs in the boot

I'm going to speak to a company today with regards to what I can do to stiffen the rear up a bit.

Try speaking to Darkside Developments.

 

[fka]

There does seem to be something unusual about T5 noseweight limits - on ClubTouareg the Aussies have noted that the maximum tongueweight (aka noseweight) reduces substantially as the car is loaded, with full tongueweight only available with no rear passengers and no rear load.

Don't the Aussies have a much higher initial tongue weight than we do in Europe? i.e. they're allowed to load closer to the actual limit of the rear axle. Where as we are limited by EU/UK law. Hence Aussies load the rear seats or boot, meaning they have to reduce the max tongue accordingly as to not exceed the limits of the axle?!

 

[johnb80]

Don't the Aussies have a much higher initial tongue weight than we do in Europe? i.e. they're allowed to load closer to the actual limit of the rear axle. Where as we are limited by EU/UK law. Hence Assies load the rear seats or boot, meaning they have to reduce the max tongue accordingly as to not exceed the limits of the axle?!

Australian caravans are very much heavier duty than UK ones, meant for off-roading, high ground clearance etc. Weights average at 3 tonnes and above, noseweights are very high compared to European caravans.

They certainly go for it in a big way.

 

[fka]

Same in the US. They all have the axle set towards the rear of the trailer chassis which also increases the nose weight and in theory stability.
I've done a bit of reading about weight distribution hitches (purely out of interest). Have to say I don't get it. The moment the WDH applies lifts weight off the rear axle of the tow vehicle and distributes it to the trailer axle and front axle of the tow vehicle.
The WDH apparently maintains the tongue weight if measuring the force applied to the tow ball but all it's doing is applying the same downwards force to the tow ball, with that force then distributed to the aforementioned vehicle and trailer axles. i.e. you've actually reduced the tongue weight on the rear axle. Which is exactly the same as simple reducing the tongue weight of the trailer which can be achieved by loading it differently!
I guess the WDH will increase friction between the hitch and tow ball, which would reduce sway but there's far simpler ways of increasing friction on the tow ball or generally on the pivot, as currently and historically practiced in Europe.

I digress - that's a whole different and very polarised topic in both the US and Aus ..

 

[Black Grouse]

Don't the Aussies have a much higher initial tongue weight than we do in Europe? i.e. they're allowed to load closer to the actual limit of the rear axle. Where as we are limited by EU/UK law. Hence Aussies load the rear seats or boot, meaning they have to reduce the max tongue accordingly as to not exceed the limits of the axle?!

It's not EU/UK law that restricts noseweights, but it seems common in EU/UK for noseweight to be limited to 4% of the towing limit, which is a EU/UK minimum. The Aussies and Americans run heavier caravans AND expect higher noseweight (tongueweight) %, typically 10%. Early versions of Touareg had a 350 kg limit out there but reduced to 280 kg on the T4 - compared to 140 kg limit on Touaregs sold in EU/UK.

Most caravans sold in EU/UK have a 100kg limit applied to their hitch anyway.