Tow Bar

[GeorgeB]

2 hours ago, J.R. said:

 

Could you or anyone enlighten me on what these legal requirements are as regards reprogramming the ECU, connection to the vehicles electronic systems etc please?

 

Legal requirements for fitting an aftermarket towbar are:

1. The towbar itself must be the correct one for the vehicle, that is to say that it is designed specificaly for the vehicle it is being fitted to.

2. The design & subsequent testing must be approved to EC 94/20 type approval. These regulations were introduced in the United Kingdom on 1st August 1998 as a part of the wider European Whole Vehicle Type Approval. In a nutshell, the regulations mean that for passenger cars registered on or after this date, if fitted with a towbar, the towbar must be designed and manufactured to EC94/20 standards.

3. An EC Approved towbar will carry a plate or other durable label bearing the EC approval number plus other information including the S-Value (maximum tested noseweight) and the D-Value (the test load as calculated by EC94/20 requirements - note the D-Value is not the same as the towing capacity). The main requirements of an EC Approved towing bracket are that it is fitted to all of the towbar mounting points specified by the vehicle manufacturer, that it has undergone a rigorous testing procedure overseen by the Vehicle Certification Agency (VCA), and that production towbars are subject to Conformity of Production (CoP) to ensure that production towbars are manufactured to the same standards as required by the initial test towbar.

4. There are no regulations re re-programming the the ECU, however there must be either an audible device, or display within the drivers line of sight, that shows that the indicator lights on the towed trailer (or caravan) are workng in sinque with the vehicles indicators. but by using the genuine factory towbar wiring loom, you gain the following; Its a plug in & play fitment, the ECU knows that there is a trailer coupled to the car & also disables the rear fog lights on the car but not on the trailer, the indicator repeater appears in the dash, and the fitting agent doesn't have to fabricate a wiring loom, thus saving you more labour charges!

Edited 10 August, 2020 by GeorgeB
Additional information

[J.R.]

Thanks, confirmed what I thought, I was concerned that maybe something more needed to be done electrical or ECU wise.

 

I have a simple bypass relay that takes a miniscule triggering current from the lighting circuits to trigger the individual relays, it does not affect the bulb sensing circuits, its the first one that I have ever had since the 80's that has a decent audible warning, discreet but loud enough to be heard, that doesnt change its frequency or sound like a strangled cat or need sensing coils moved apart, all the others either didn't work repeatably or sounded awful and needed silencing.

 

The downside, and its an important negative point is that the module draws current at all times and will reduce the vehicles standby battery life.

 

One day I will find out how the OE system senses the simple N/O contact or linked terminals to know when a towing plug is inserted and what reprogramming is required to enable said function, I am hoping it can be done without a seperate canbus controller, then I will get it all working and benefit from the features like fog light isolation and the stability systems, I dont have reversing sensors to be concerned about.

[Kamikazekid]

I’ve been getting prices this week for a detachable tow bar. I thought I’d give my local Skoda dealer a call so see what they can offer. They quoted me £1137 to supply and fit the OEM drop down one. Although it’s expensive, I was surprised that they came up with this as an option as I’ve read other people have been told by their dealer that retrofitting the OEM one is not possible. Skoda said they would need a week or two to get the parts as they would be ordering from the Czech republic.
 

Even more interesting that this, they quoted about £3 more to fit a 3rd party detachable towbar! Very strange!

 

I think I will end up going for the Bosal one through PF Jones due to good feedback on this thread and it’s pretty much half the price. Although the OEM one would be a nice touch.