**September Sale NOW ON SAVE £120 on fitting**
Valid on orders placed between 01/09/2021 and 30/09/2021

Vehicle Coding

When having a Towbar fitted to your vehicle it is often required to 'code' the vehicle so it knows how to respond whilst the extra load is on the vehicle.

Often we hear 'I will only be towing once or twice a year for the tip' and 'it's only for a bike rack' however, where coding is required its essential that it should be carried out and even more importantly it needs to be done correctly.

What does it do?

This can vary on all vehicles that require Towbar coding to be applied, just because the lights work or there's no warning lights on the dash does not mean everything is as it should be. Your vehicles are often equipped with safety systems that hopefully you will never need to know are working, but it is vital that they are ready to work as they were intended to when needed. Here at Telford Towbars we use many different systems to ensure that any coding needed to be done on your vehicle is completed without having to take the vehicle to a main dealer.

Please be aware that it is impossible to tell what systems are available on every vehicle make, model and year, and some systems are only available on Towbars fitted by the manufacturers. But when we retrofit a Towbar and vehicle specific electrics we g is needed we complete it for you.

Systems and a brief overview

Light activation

Some vehicle will not output any lights to the trailer module before coding.

Parking Sensor cut off

Where factory fitted sensors are present they can often be deactivated automatically through correct coding whilst the vehicle is towing. Often this will provide a trailer symbol in your display whilst reversing when towing. This however will not stop a fixed flange bar or a fixed swan neck from being detected whilst not towing.


The above systems are the most visual and noticeable effects from coding, however there is a lot more going on with your vehicle!

Many vehicles have advanced safety systems and convenience system within the electronics that are essential to be correctly coded to know that the vehicle is towing.

These can include:

Trailer stability

Trailer stability or trailer sway control is an essential part of the vehicles braking and dynamics system. This system dependant on manufacture, model and even build year and can sometimes be already built in, or often only is activated by correct coding. This system can detect a trailer sway or snake and help to correct it - often with no input or notification to the driver! This is possibly the most important safety feature for towing your vehicle may have.

Lane Change Warning

Lane departure warning and blind spot assist uses radars at the rear of the vehicle either side of the bumper that can detect a vehicle in your 'blind spot' and notify the driver. This has to be coded to know when the vehicle is towing to avoid malfunction and error messages displayed on the dash as the radars can pick up your caravan, trailer or bike rack.

Front Assist/Emergency braking/Pre-Sense/Adaptive Cruise Control

Many vehicles have this feature that utilises a radar or camera at the front of the vehicle to warn the driver when approaching another vehicle, these systems again require correct coding to know when the vehicle is towing to be able to react accordingly and prevent errors on the instrument cluster.

Transmission and gear change

Some automatic transmission vehicles require to be coded to know when towing to enable the gearbox to stay in gear longer due to the extra load from towing - this can help to prevent excess stress and load being applied to the transmission.

Engine Cooling

When towing the extra load on the vehicle can require engine cooling fans to run for longer and to help avoid the vehicle from overheating whilst on the road to that summer holiday.

Navigation systems

Some vehicles even require the navigation system to be correctly coded so when towing it will try to avoid narrow lanes or restricted routes! Nobody wants to reverse a 15ft caravan down a farm path!

Boot/Tailgate operation

If your vehicle is equipped with an electric tailgate then there is the possibility of opening the boot into the bike rack, caravan or trailer causing damage to them. If available the vehicle can be coded to prevent this from happening when towing.

Have any questions? Let us know and we'll be happy to help!


Right Connections Logo

Telford Towbars is a trading name of Complete Diagnostics Ltd
502-503, Queensway Business Park, Hadley Park, Telford TF1 7UL

In partnership with:

Brink Logo