Various systems for monitoring vehicle lighting play an important role in the operation of modern vehicles and trailers. Terms such as CAN data bus, electronic turn signal monitoring, and audible turn signal monitoring frequently arise, particularly in the context of trailer hitches, bicycle carriers, and auxiliary lighting. Although all three systems relate to the monitoring of lighting functions, they differ in terms of technology and operation.

The CAN data bus

The CAN data bus (Controller Area Network) is a digital communication system used in almost all modern vehicles. Various control units, such as those for the engine, lighting, brakes, or assistance systems, exchange information with one another via the CAN bus. Lighting is no longer controlled directly through simple electrical circuits; instead, it is electronically monitored and regulated.

When a trailer or a rear-mounted bicycle carrier with lighting is connected, the electrical kit’s module detects an additional load. It reports this to the vehicle via a specific CAN message over the data bus, allowing certain vehicle systems to be deactivated. The system can then activate functions such as trailer turn signal monitoring, disable parking aids, or switch off the rear fog light on the towing vehicle. A vehicle-specific CAN bus electrical kit is required for this functionality.

Electronic and acoustic turn signal monitoring

Electronic turn signal monitoring is a system that visually monitors the operation of turn signals on trailers or rear-mounted carriers, signaling if the trailer’s turn signal lights fail to work. It typically operates via an additional indicator light on the dashboard or within the driver’s field of vision. This light flashes in sync with the turn signals, confirming they are functioning correctly on the trailer or bicycle carrier. If a malfunction occurs (such as a turn signal failure), the flashing pattern changes to double the frequency, or the indicator light remains off. Electronic monitoring systems are common in older vehicles lacking a CAN data bus but can also serve as a simple solution for newer vehicles. By comparison, the “C2” indicator is a specific type of additional light used to show the driver the status of the trailer’s turn signals.

Acoustic turn signal monitoring serves the same purpose as the electronic version but utilizes an audible signal. When the turn signal is activated, a clicking or beeping sound confirms to the driver that the signals on the trailer or rear-mounted bike carrier are active. A malfunction is indicated if the sound fails to occur or changes. This type of monitoring is frequently used in retrofit solutions where a visual display in the cockpit is not feasible or included in the design.

Functions at a glance

In summary, the following characteristics apply to the various functions:

CAN data bus

• is a digital communication system
• is used in modern vehicles
• control units exchange information via the CAN bus
• when a trailer or rear-mounted cycle carrier is used, the electrical kit module detects the additional load and reports it to the vehicle via the CAN data bus
• this enables the vehicle to control systems such as the rear fog light cut-off

Electronic turn signal monitoring

• is a system for monitoring turn signal operation on trailers and electrical kits
• signals if the trailer turn signal lights are not working
• usually operates via an additional indicator light on the vehicle’s dashboard
• indicates that the turn signals on the trailer or rear-mounted cycle carrier are functioning correctly
• in the event of a malfunction, the flashing frequency changes or the indicator light goes out

Audible turn signal monitoring

• is a system for monitoring turn signal operation on trailers and electrical kits
• signals if the trailer turn signal lights are not working
• indicates a malfunction via an audible signal (beep or clicking sound)
• confirms to the driver that the trailer turn signals are active
• if the sound does not occur or changes, there is a fault in the turn signal operation

The difference between a braked and an unbraked trailer is particularly important for safety and handling. Certain legal requirements should also be taken into account. The two types of trailers differ not only in their technical specifications but also in their permissible weight, intended use, and the requirements placed on the driver and the towing vehicle.

The unbraked trailer

As the name implies, an unbraked trailer does not have its own braking system. Consequently, when braking, the trailer is slowed down solely by the brakes of the towing vehicle. This means that the car must provide the entire braking force. Therefore, one must also take the additional mass of the trailer into account when braking.

This is also the reason why unbraked trailers in Germany and most European countries are subject to strict limits regarding their permissible gross weight. As a rule, they must not exceed a maximum permissible gross weight of 750 kilograms. If the trailer’s permissible gross weight falls within this limit, it is permitted for use without brakes, provided the towing vehicle is approved for that specific towing load.

Due to these weight restrictions, unbraked trailers are frequently used for lighter loads, such as garden waste, small pieces of furniture, motorcycles, or lightweight construction materials. However, it is important to note that handling characteristics are significantly influenced by the trailer’s weight and load. Factors such as longer braking distances, increased strain on the vehicle’s brakes, and a greater susceptibility to swaying can be significant for the driver, particularly at higher speeds or when driving on downhill gradients.

The braked trailer

A braked trailer, on the other hand, is equipped with its own braking system, usually an overrun brake. An overrun brake operates mechanically: when the towing vehicle brakes, the trailer’s inertia causes it to push against the trailer coupling. This pressure is transmitted via a push rod to the trailer’s brakes, actively braking the trailer’s wheels. As a result, braking force is distributed equally between the towing vehicle and the trailer, significantly improving driving safety.

Braked trailers are therefore designed to handle significantly heavier loads. In Germany, depending on their design and the towing vehicle’s specifications, they may have a permissible gross weight exceeding 750 kilograms, often up to 3,500 kilograms. Consequently, they are primarily used in commercial sectors, construction, and agriculture, as well as for transporting heavy vehicles, boats, or horses. Caravans are also typically equipped with brakes, as their weight often far exceeds the limit for unbraked trailers.

However, the higher weight capacity of a braked trailer comes with increased technical complexity. The braking system requires regular maintenance and inspection, usually carried out as part of the mandatory vehicle safety inspection. An advantage of braked trailers is their greater stability on the road; the trailer’s own braking system allows for shorter stopping distances and improved control, factors that are particularly important during emergency braking or when driving on downhill stretches.

Legal considerations

Another difference between the two types of trailers concerns the legal requirements. For both braked and unbraked trailers, the towing vehicle’s permissible towing capacity must be observed. Driver’s license categories also play a role: a Class B license only permits driving vehicle combinations up to certain weight limits, whereas a Class BE license is often required for heavy, braked trailers.

If you want to transport your bicycles, a rear-mounted bike carrier is one of the most practical and convenient solutions. Compared to a roof rack, it offers numerous advantages, especially loading. The bicycles don’t need to be lifted overhead, which not only saves energy but also reduces the risk of damage to the vehicle or the bicycles. The rear-mounted bike carrier is mounted directly onto the tow ball of the trailer hitch and is usually ready for use within minutes. Practical loading ramps allow you to easily slide the bicycles onto the carrier and then securely fasten them. This is a great advantage, especially for heavy bicycles such as e-bikes or mountain bikes. And then you’re almost ready to go, right? Not quite, since a license plate for the rear-mounted bike carrier is essential.

The license plate for the rear bike rack

Unfortunately, it’s not quite that simple; there’s one more hurdle. You have to equip your rear bike rack with a third license plate. An additional license plate is always required if the vehicle’s rear license plate is obscured. This is always the case with rear bike racks, regardless of whether the rack is loaded or unloaded. Taillights and turn signals must also not be obscured, which is why many rear bike racks have their own lighting unit.

Homemade license plates are not permitted; you must obtain an official third license plate. You can get this from your local vehicle registration office. The cost varies depending on the location, but is generally manageable and typically costs between €20 and €40. The license plate is identical to your vehicle’s regular license plate, including stickers, and can remain permanently attached to the rear bike rack. Most rear bike racks on the market have an integrated license plate holder.

Fines for non-compliance

If you are driving with a rear-mounted bike rack and don’t have a third license plate, you risk a fine if stopped by the police. This can be up to €40, and you will also receive a point on your driving record. Depending on the situation, further warnings may follow, for example, if the lights or license plate are poorly visible. To avoid trouble, unnecessary costs, and potential delays, you should therefore always check before starting your journey that the rear-mounted bike rack is correctly installed, fully illuminated, and properly equipped with a third license plate.

Anyone driving with a rear-mounted bike rack on their car must comply with certain legal regulations. In Germany, the Road Traffic Regulations (StVO) and the Road Traffic Licensing Regulations (StVZO) stipulate how a rear-mounted bike rack may be used. The basic principle is that the rack and the bicycles being transported must not impair road safety. This means they must be firmly and securely mounted so that they cannot come loose or slip during the journey.

Increase visibility with appropriate lighting on your rear bike carrier

An important factor for safe riding with a rear bike carrier is the visibility of the lights and license plate. Obscuring the taillights, turn signals, or license plate with the carrier is not permitted, so an additional light bar with all required lighting functions and a license plate holder is mandatory. The license plate must always be clearly legible and properly illuminated. In Germany, a third, so-called repeater license plate should also be used on the rear bike carrier for this purpose; this plate must match the official license plate number.

Pay attention to the dimensions

The (new) dimensions of the vehicle are also relevant when using a rear-mounted bike rack. In Germany, the load may extend a maximum of 1.5 meters beyond the rear of the vehicle. For journeys under 100 kilometers, this overhang can be increased to up to 3 meters, in which case special markings with flags are required. The total width of the vehicle, including the rack and bicycles, must not exceed 2.55 meters. Care must always be taken to ensure that no sharp edges or protruding parts endanger other road users.

Caution regarding speed!

In Germany, there is no general legal speed limit for driving with a rear-mounted bike rack. The manufacturer’s specifications for both the rack and the vehicle are decisive. Many manufacturers recommend a maximum speed of 120 or 130 km/h.

This applies outside of Germany 

In other EU countries, regulations may differ. For example, in Italy and Spain, a red and white warning panel is mandatory whenever cargo protrudes to the rear. This also applies to bicycles on a rear carrier. Austria may also have marking requirements, and in France, the visibility of license plates and lights is particularly strictly monitored.

Anyone traveling with a rear-mounted bike rack, both domestically and internationally, should therefore inform themselves about the respective national regulations before starting their journey in order to avoid fines and safety risks.

To transport bicycles safely and comfortably, a rear-mounted bike rack is the most practical solution. There are various mounting options for transporting bicycles, which differ depending on the vehicle type and the rear-mounted bike rack model. Generally, rear-mounted bike racks are attached either to the tailgate, the trunk lid, the spare tire, or – most commonly and safely – to the trailer hitch.

Safe on the road: The towbar-mounted bike carrier

The simplest way to transport bikes is by mounting a towbar-mounted bike carrier. This solution is considered particularly convenient and user-friendly. With this type of mounting, the carrier is placed directly onto the tow ball of the towbar. Installation is tool-free: The carrier is placed on the tow ball and then secured – depending on the model – with a tension lever or, for example, a clamping device. Modern systems now feature an integrated locking mechanism that prevents the carrier from coming loose while driving and also protects it against theft.

A major advantage of towbar-mounted bike racks is their versatility. They easily accommodate multiple bicycles, often including e-bikes, and are generally quite easy to load, especially when using loading ramps. Furthermore, such a rack sits very securely on the vehicle, significantly reducing the impact on handling compared to other mounting methods. Many models are also foldable, allowing access to the trunk even when loaded.

When mounting, ensure that the tow ball of the trailer hitch is clean and free of grease, otherwise the clamp will not engage reliably. To mount, place the rear bike carrier onto the tow ball and engage the clamping mechanism so that the carrier securely grips the ball. After mounting, the carrier should be firmly secured and checked for tightness. Only then should the bicycles be placed in the designated rails and secured.

Alternatively: Mounting on the tailgate or the spare wheel

One option is a rear-mounted bike rack. This is attached to the top and bottom edges of the tailgate or trunk lid using straps and hooks. The straps must be pulled taut so that the rack fits as securely as possible against the vehicle. It is particularly important to protect any contact points between the rack and the car with protective film or rubber bumpers to prevent any paint damage. This transport solution is relatively inexpensive and flexible, but often has a limited load capacity and is not suitable for every vehicle.
Another option is a rear-mounted spare tire carrier, which is primarily used on SUVs or vehicles with an externally mounted spare tire. The carrier is mounted directly onto the spare tire and secured with screws. This option is stable, but only suitable for vehicles with a compatible design.

The Renault Rafale E-Tech is the latest, modern SUV from the French manufacturer. This SUV is ideally suited for towing and can easily demonstrate its towing capacity with the right towbar.

Our product range includes a suitable towbar for the Renault Rafale E-Tech, equipped with the MVG 2040 automatic system. The ball mount on this system is vertically detachable and operated via a rotary knob.

The benefits of the detachable towbar for Renault Rafale E-Tech 05/2024 model

• vertically detachable towbar, MVG towbar 2040
• No visible cut-out required 
• automatic system removal by twist grip
• automatic locking device when fitting
• also for Full Hybrid & Hyper Hybrid Plug-In

Technical data for detachable towbar

• D-value: 9,4 kN
• Towing capacity: 1709 kg
• Trailer load: 90 kg

The detachable towbar for your Renault Rafale E-Tech 05/2024 model can be found in our MVG-shop. The item number is 0990 A.

Find out more about our products in our other shops:

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www.mvg-ahk.ch
www.mvg-ahk.lu
www.mvg-ahk.be
www.mvg-ahk.nl

The Renault 5 E-Tech is one of the latest models from Renault to hit the European market. The small car features a sporty design and can also be retrofitted with a towbar, allowing it to transport bicycles, for example, using a rear-mounted bike rack.

Our range includes a detachable towbar equipped with the MVG 2040 automatic system. With this system, the ball bar is operated via a rotary knob, requiring only a few simple steps. Our towbar does not require any visible changes to the appearance of the small Renault 5 E-Tech.

The benefits of the detachable towbar for Renault 5 E-Tech 09/2024 model

• vertically detachable towbar, MVG towbar 2040
• No visible cut-out required 
• automatic system removal by twist grip
• automatic locking device when fitting

Technical data for detachable towbar

• D-value: 5,2 kN
• Towing capacity: 732 kg
• Trailer load: 63 kg

The detachable towbar for your Renault 5 E-Tech 09/2024 model can be found in our MVG-shop. The item number is 0992 A.

Find out more about our products in our other shops:

www.mvg-ahk.at
www.mvg-ahk.ch
www.mvg-ahk.lu
www.mvg-ahk.be
www.mvg-ahk.nl

The MG ZS, available in both gasoline and hybrid versions, is a modern SUV, even though it’s one of the smaller models. Thanks to a suitable aftermarket towbar, the MG ZS can also be used as a tow vehicle and pull small trailers.

We offer a detachable towbar for retrofitting. Equipped with the MVG 2040 automatic system, the towbar is easy to operate via a rotary knob and requires no modifications to the vehicle’s appearance.

The benefits of the detachable towbar for MG ZS Petrol & Hybrid+

• vertically detachable towbar, MVG towbar 2040
• No cut-out required 
• automatic system removal by twist grip
• automatic locking device when fitting

Technical data for detachable towbar

• D-value: 4,3 kN
• Towing capacity: 500 kg
• Trailer load: 50 kg

The detachable towbar for your MG ZS Petrol & Hybrid+ can be found in our MVG-shop. The item number is 1900 AS.

Find out more about our products in our other shops:

www.mvg-ahk.at
www.mvg-ahk.ch
www.mvg-ahk.lu
www.mvg-ahk.be
www.mvg-ahk.nl

With the Renault Scénic E-Tech, Renault is launching the next modern electric vehicle. This SUV is a family car and offers plenty of space. If you plan to take the Renault Scénic E-Tech on vacation, a towbar can be helpful, for example, for transporting bicycles.

The towbar in our range can be easily retrofitted and can be set up in just a few steps. Thanks to the MVG 2040 automatic system, operation is quick and easy via a rotary dial. With our towbar, there’s no need to alter the appearance of the modern SUV.

The benefits of the detachable towbar for Renault Scénic E-Tech 01/2024 model

• vertically detachable towbar, MVG towbar 2040
• No visible cut-out required 
• automatic system removal by twist grip
• automatic locking device when fitting

Technical data for detachable towbar

• D-value: 7,8 kN
• Towing capacity: 1179 kg
• Trailer load: 80 kg

The detachable towbar for your Renault Scénic E-Tech 01/2024 model can be found in our MVG-shop. The item number is 0991 A.

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Check out the video as well:

Find out more about our products in our other shops:

www.mvg-ahk.at
www.mvg-ahk.ch
www.mvg-ahk.lu
www.mvg-ahk.be
www.mvg-ahk.nl

As in every year, we are once again committed to a good cause and are supporting a local organization. We are very pleased to be supporting the Eschweiler branch of the German Child Protection Association (Kinderschutzbund) with a donation this year. We were delighted to welcome the branch’s managing director, Thorsten Ingermann, and its chairwoman, Mariethres Kaleß, to our premises for the donation handover.

Donations for a Lived Community

“Many families and children simply need to feel seen,” says Mariethres Kaleß at our donation handover, as she explains how the cultural and recreational activities at the DKSB Eschweiler are organized. Often, she says, not much is needed to achieve great things with limited resources. For example, the DKSB’s playground festival requires little effort to attract a large number of local families, foster networking, and provide an enjoyable celebration together. The goal of every event: to create shared memories, promote community, and have fun together. Thorsten Ingermann emphasizes the diverse mix of participants at the events; the children often come from different parts of town and have varied personal backgrounds. “Events like the playground festival counteract isolation and ensure that no one feels left out,” Ingermann continues.

Integration is a top priority

The playground festival is just one example of the wonderful work the German Child Protection Association (DKSB) does locally: Its more than 90 employees are dedicated to providing childcare at five primary schools in Eschweiler, now caring for over 800 children every day. They offer not only morning and full-day care during school days, but also during school holidays and on bridge days, giving children the opportunity to grow together with their peers and protecting children who face various challenges in their daily lives.

At the same time, the Eschweiler branch of the German Child Protection Association also helps families and adults. They offer support for parents, training opportunities for young people, and continuing education opportunities, including for adults. Ms. Kaleß reports on a group of dedicated volunteers who help refugees navigate bureaucratic processes and government offices, while also working to overcome language barriers and teach German. “This is integration in action, and we are delighted to be able to support this work this year,” says our Managing Director, Michael Pütz.

Want to learn more about the work of the DKSB Eschweiler, or even get involved yourself? On the website you’ll find lots of information about the valuable work of the Eschweiler local branch.