Trailer Stability Program (TSP)

[peter_374235415]

Hi, I posted a topic regarding the fitment of a tow bar to my 2006 VW Passat. The cost of the tow bar is dearer than my last Passat due to (I'm told) the vehicle specific wiring to add Trailer Stability Program. I had been told on my previous Passat to turn off the Electronic Stability Programe (ESP) when towing but now it appears that VW along with General Motors Mercedes etc are fitting TSP. On a web site I found the following text:-

"Trailer Sway Control technology is introduced to improve trailer stability and increase towing safety. It helps reduce trailer sway and improves the SUV's handling especially in difficult driving and towing conditions.

The technology uses vehicle yaw sensors that detect sway caused by the trailer. It then applies brake pressure on one front wheel to counteract the sway caused by the trailer. It will also apply brake pressure on all four wheels to slow down the vehicle. If the trailer sways to the other side of the vehicle, the controls will increase brake pressure on the other side. This ensures that the vehicle and the trailer are under control".

Does anyone have any further info on this, if your car has it have you noticed better towing conditions. None of the (Good) tow bar fitters near me will fit a tow bar on my Passat without this hence a £600+ charge.

I welcome any comments or experience of this you may have.

 

[Angus1]

Hi Peter,

Very topical this as I`ve just had a very long conversation with the workshop foreman at my local VW dealer on this subject.

I had a quote for nearly

 

[peter_374235415]

Thanks Angus, I'm so confused. I've been told by some reputable fitters that my insurance (both caravan and car) may be invalid without TSP as the car is designed to have it when towing (they won't even fit the tow bar without it)and that ESP will not detect the caravan and may cause additional problems if the car/caravan were to come into difficulty. There is also the issue of fitting a bicycle carrier with electrics as the car would sense a trailer when one would not be there. I have (or am going down the route) of having the VW garage fit a VW approved detachable towbar at

 

[Lutz]

Somewhere in my files I have a comparison test of a Merc M towing a caravan with and without TSP and the difference was quite appreciable.

I don't quite understand what the wiring harness to the towbar has to do with it because all the electronics for TSP are within the car.

Unfortunately, it seems, more and more manufacturers are fitting TSP to their cars without adequately informing the owners about the function.

The big advantage of TSP compared to a conventional stabiliser is that it is an active system, i.e. it doesn't just increase the stiffness of the joint between car and caravan like other stabilisers, but it actively controls any swaying motion by applying the brakes accordingly.

Normal stabilisers only improve stability by increasing the threshold limit of when a snake can occur, but they cannot actually prevent the outfit from exceeding this limit. With the TSP feature, there is no such restriction in protection because it actively applies the brakes of the car accordingly until stability is restored.

It is quite uncanny to experience TSP in operation. If, for testing purposes, for example, you deliberately get the trailer to sway, the car will just slow down all by itself even though you may still have the foot on the accelerator.

 

[rob_jax]

Hi,

The wiring harness just needs to detect the connection of the caravan - which could be something as simple as a micro-switch in the ISO 11446 13-pin Euro connector - and this is signalled to the car ESP computer.

My E-class has TSA (Trailer Stability Assist) and was fitted with a detachable tow-bar, and the information I received went something like this:

"The TSA program is an extra function pre-programmed into the ESP system - designed to offer drivers greater stability when towing - applies appropriate braking to individual wheels to counteract any fishtailing"

What I also seem to remember (but can't find a reference to) is that when towing, the TSA program obviously reacts differently to the standard ESP program when given the same trailer movement - and that consequently ESP may not give the optimum response.

In particular I can't find the part that ranks the best order when towing - TSA then ESP then nothing or TSA then nothing then ESP

Robert

 

[GeorgeB]

Peter,

You cannot add TSP just by using a special wiring harness, the TSP system must be "factory fitted" when the vehicle is built.

All VW group (VW, Audi, Seat, Skoda) retro fit towing equipment is more expensive when fitted by a dealer than when it's done by an independant specialist using non VW approved items.

The VW group approved tow bars & electrics are designed specifically for the models and go through rigorous TUV approval, (Lutz will know all about the TUV!) before being approved for fittment to VW group products.

Having seen TSP in action (being demonstrated how it works) on an Audi Q7, I can say it's one smart bit of kit!

Although the TSP uses the simular technology as ESP (Electronic Suspension Programming) and utilises the selective braking process, TSP is NOT linked to the ESP, indeed if you have a vehicle with TSP the ESP will probably never come into operation, but if your vehicle has only ESP, or has TSP, and you drive in such a manner as to invoke the ESP whilst towng a caravan, you've already lost control of the outfit and will be extremely lucky if you don't loose it big time!

The only thing fitting bycicles to the tow bar will probably interfere with is parking aid sensors (if you have them fitted.

It's extremely unlikely it will have TSP if it does not have factory fitted towing equipment.

Hope this helps

 

[Lutz]

Yes, it would be very difficult to retrofit TSP. To my knowledge, second generation ESP which applies brakes individually to each wheel rather than to each axle is necessary for TSP, i.e. you can't have TSP without ESP but you can have ESP without TSP.

I agree that without TSP you will already have run into trouble if you drive in a manner that ESP has deployed but I do not quite see how towing the caravan would make the situation any worse than it already is. Under the same conditions, driving without ESP would be just as critical. In other words, ESP without TSP might not help but it certainly shouldn't make things worse.

 

[peter_374235415]

Thanks very much for your replies. ESP and TSP ? I'm still rather confused!! Anyway, I have dedcided to have the detachable towbar fitted by the VW dealer I bought the car from who have said that the TSP function will apply. I'm happy to a certain degree as the fitting of the tow bar will comply with the electronics of the vehicle, insurance and warrenty (piece of mind). I just don't understand how some fitters can fit it for

 

[Angus1]

Peter,

The company that fitted my bar are the manufacturers of towbars (and have done for decades) and their bars are approved.

I forgot to mention that the VW dealer down the road have bars fitted there as well.

You may think a

 

[peter_374235415]

Angus, I'm by no means questioning your tow bar or its fitters. As I said I have had 3 independant quotes and a VW quote. The VW quote is slightly dearer but only by

 

[Angus1]

Peter,

If you want to know why the VW quote is what it is,ask for a breakdown of costs. My dealer did this, and there was no way I was going to pay 8 hours labour @

 

[Lutz]

Here's an excerpt straight from the VW New Passat press release:

ESP+ Trailer stability: We know plenty of you like hitching a trailer to your family cars; Passat now makes these journey's even safer. The ESP+ Trailer Stability system automatically slows the vehicle to a safer speed if it senses that the trailer is beginning to sway from side to side.

 

[peter_374235415]

I've made a response partly to my original question under Passat and new towbar. I will add a further reply tomorrow when I have spoken to the VW technician to find out about TSP which my Passat now has had activated.