Whether your fleet is large, small or a single tractor-trailer, no one wants to deal with a rollover. They are dangerous, expensive and can damage your reputation. That’s why Bendix offers information on the operation and maintenance of trailer roll stability systems designed to help prevent rollovers.
“Total stability systems for tractors – like the Bendix ESP system – have been mandatory on new tractors since 2017 and were standard on many makes and models before that,” said TJ Thomas, director of marketing and customer solutions – Controls Group at Bendix. . “Trailer Sway Stability Technology provides additional rollover protection whether or not the attached tractor is equipped with a stability system, which is important in situations where a fleet might not experience all of the specifications of every tractor that clings to its trailers.”
Trailer Stability Basics
A Trailer Roll Stability Program (TRSP) uses sensors and wheel-end controls to detect conditions that may lead to a rollover, then intervene with braking applications, usually before the driver turns over. realize that intervention is necessary. There are two basic types of trailer TRSPs: single-channel and multi-channel.
Single channel setups are typically built on a two sensor and one modulator (2S/1M) anti-lock braking system (ABS) setup. It is a simple and popular solution that adds less weight without sacrificing performance and allows for easy installation and maintenance. It is also a good choice for fleets looking to add trailer stability to an existing ABS system.
Multi-channel TRSPs cater to different demands. They will be easier to install on vehicles with ABS systems already built with multiple sensor and modulator configurations, such as 2S/2M or 4S/2M. Additionally, tandem axle trailers are best served by a multi-channel option, since each axle is detected and controlled. Most of the key components of a multi-channel TRSP are efficiently housed in a single, environmentally-protected modular unit.
What Drivers Should Know About Trailer Stability
“The first thing any driver needs to know is what type of stability system, if any, is on the trailer they’re towing,” said David Dennis, Bendix Technical Team Supervisor. “It’s pretty easy to spot. You should be able to tell by looking at the information sticker on the trailer if it has ABS or roll stability. And just to be clear – if it has stability, it’s built on ABS. You can’t have stability without ABS controls.
Safety technologies like trailer stability complement safe driving practices, Thomas said. No commercial vehicle safety technology replaces a competent, alert driver practicing safe driving techniques and proactive, comprehensive driver training. Responsibility for the safe operation of the vehicle rests with the driver at all times, which is why it is important that the person behind the wheel be aware of the capabilities of any system and the possible interventions.
Monitoring a trailer stability system from the cab just requires a watchful eye. There is an amber warning light located on the left rear side of a trailer, in view of the driver’s side mirror. If illuminated, there is an active Diagnostic Trouble Code (DTC) and it should be checked as soon as possible.
Additionally, on all tractors built after 2001, the trailer will communicate problems to the tractor through the power line carrier, which activates the warning lights on the instrument panel. It is important to note that a stability light does not mean that the trailer does not have brakes. It simply indicates that the ABS/stabilization system is not working; the brakes will operate normally.
Drivers can also understand trailer stability issues by listening to the “recall test” the system performs on start-up. When the tractor is turned on, the air brake system goes through the process of triggering the individual modulators to ensure they are working, creating a series of clicks and “chuffs”. A faulty system or modulator will not produce the chuff sound.
Information key for diagnostics
When it comes to diagnosing a problem with a trailer stability system, the details matter. If you are the driver, try to provide as much information about the situation as possible.
Do you notice, for example, that the trailer pulls during long right turns – like on a cloverleaf – or that the light comes on when you pass over railway tracks? Anything you can let technicians know about driving situations, road conditions, or the weather is helpful. Owner-operators can also review some DTCs themselves, as the trailer sticker will include basic information about the blink code, giving insight into the severity of the fault.
Wiring-related issues are among the most common causes of trailer stability system failure, as weather and exposure can easily contribute to wiring issues. In fact, often the system’s Electronic Control Unit (ECU) is not the root cause, which reinforces the importance of knowing as much information about the circumstances as possible.
Technicians should start by using a diagnostic tool to identify the ABS or stability system installed on the trailer. From there, more in-depth analyzes of the problem may be needed, emphasizing the importance of using up-to-date diagnostics.
“Safety and uptime depend on getting the right results quickly on the shop floor, so you need to make sure your diagnostics are equipped to recognize and support the latest ECUs and other connected components,” Dennis said. “Trailer stability maintenance is a three-step process: identify the fault, resolve the fault, and clear the code. Making the right choices along the way is what will get your vehicles back on the road and rolling. safely. “
The Bendix Tech Tips series can be found in the Bendix Media Center at knowledge-dock.com.