Beiträge getagged mit: "trailerdrive"

Driving on a mountain, i.e. uphill or downhill, is still a challenge for many drivers even after driving school. With the trailer, it can be even more difficult, not least because of the additional weight. In this article we explain to you which points you should pay particular attention to when driving with a trailer on roads with slopes or inclines and how you can master these hurdles well.

This is how you drive your trailer on an incline

If you are traveling with a trailer and have to pass an incline, the towing vehicle – especially with a fully loaded trailer – is subject to greater stress. The engine has to work on a higher level. This is easier if you shift down a gear and thereby increase the engine power. If the gear is too high, your team will slow down. You may even have to stop and start on the mountain. Although this is not impossible, it leads to unnecessarily heavy wear on the towing vehicle. If it can be avoided, then you should drive with enough foresight, shift down a gear and still not exceed the speed – this is the only way you can still be proactive. If it is necessary to start off on the mountain with a trailer, then it is essential to use the handbrake for support, as you once learned in driving school.

Trailer driving on sloping roads

Roads with gradients hold a few small pitfalls for your journey with the trailer. On the one hand, your trailer always pushes your team on journeys that go downhill. So you have to keep in mind that the entire weight of the (loaded) trailer will push from behind. On the other hand, this means that your team is a little faster than you intended, and thus, the braking distance is also longer.

So you should act early on roads with a gradient, keep an eye on the possibly higher speed early on and reduce it. At the same time, it is advisable to engage a lower gear, as you can then use the engine brake to assist. If you only brake with the brakes of the towing vehicle, it is possible that these will overheat due to the higher load and their effectiveness will decrease. Important: Never switch off the engine when driving downhill with a trailer. Switching off would cause aids such as power steering and brake booster to fail.

For some years now the PDC (Park Distance Control) system has been a standard feature of a car. When reversing sensors recognize obstacles behind the car, the board computer gives the driver an optical and/or acoustic signal.
In reality, a trailer should always be recognised as an obstacle, because it is directly at the tail end of the car. The PDC should really go haywire and permanently give warning signals. But it doesn’t – and why not? The reason is that the PDC shuts down, which is realised in various ways.
Heinz Hueber, Technical Manager of our Electrical Kit Department, explains how the Park Distance Control can be switched off with retro-fit trailer hitches and how the PDC shutdown functions.

1. Complete integration into the onboard electronics of the towing vehicle
If a towbar is installed by a car manufacturer in the factory, the electronics will be completely integrated with the onboard electronics of the towing car. Trailer operation is then activated in the board computer so that the board computer automatically knows when the trailer plug is inserted into the socket, e.g. that the car’s PDC and the rear fog light have to be switched off and possibly the trailer combination stabilisation switched on.
If a trailer hitch is retro-fitted the coupling electronics into the onboard electronics of the towing vehicle could also be integrated by a specialist workshop. For this, the control units in the vehicle must be manually activated with a tester (Caution! Not every tester can activate control units). There will be additional costs.
Unfortunately, not all car manufacturers authorise the access to the intelligent board electronics. Sometimes after a service at an authorized workshop the activation is reset. Therefore, the manufacturers of retro-fit trailer hitches solve the PDC shutdown by means of an electronic or mechanical trailer identification.

2. Control module in the electrical kit is used for recognition
A control module is built into the electrical kit delivered along with the towbar. This module detects the electrical load of the trailer lighting and passes on the information to the board electronics accordingly. Here we can latch into the board electronics of the towing vehicle, but without activation. The PDC shutdown is either switched on or off manually via a P-OFF switch, which many cars have, or automatically via an intelligent control module of the electrical kit, which also switches the trailer rear fog light on and off. Disadvantage: further driver assistance systems will not be adapted.

3. Micro-switch interrupts the power supply
The easiest solution is a mechanical micro-switch in the towbar socket. If the connector of the trailer is plugged in the micro-switch bumps off and interrupts the power supply to the PDC. At the same time the rear fog light will be switched off on the towing vehicle – only the rear fog light on the trailer will shine, not on the towing vehicle.

4. Digital communication via databus (CAN)
Nowadays many vehicles communicate via a databus. Here all information is digitally transported via a two-wire cable. The control modules are, connected with one another via the data bus, CAN (Controller Area Network) and communicate the necessary signals via the two cables, CAN-High and CAN-Low.
Technically the latest control modules of the trailer hitches could hook up into the CAN-Bus and communicate digitally with the onboard control units, but this is seldom the case.