Which Blind Spot Warning Systems Incorporate Trailers?


Blind spot warning systems are among the most in-demand safety technologies among new vehicle buyers, according to Nissan, and they are especially useful on large, long pickups that sit high and have large blind spots. Blind spot warning sensors look at a box that starts near the rear bumper and extends backward a few car lengths. The systems alert you when vehicles in other lanes enter your blind spot and are useful in preventing accidents related to lane changing. However, adding a trailer to the bumper renders the systems useless — unless those systems are updated to accommodate trailers.

Since towing is one of the most popular uses for pickup trucks — 60 percent of participants in a recent Chevrolet survey said that towing is a — some truckmakers have taken note and created new blind spot warning systems that account for trailers.

Out of the six current full-size half-ton pickups — the Chevrolet Silverado 1500, Ford F-150, GMC Sierra 1500, Nissan Titan, Ram 1500 and Toyota Tundra — only two have blind spot warning systems that adjust for a trailer. Which ones? The redesigned Ram 1500 and the Ford F-150. The other manufacturers recommend that you shut off the blind spot warning system, if your truck is equipped with it, while towing to prevent a litany of false warnings. The redesigned 2019 Silverado 1500 and the 2019 Sierra 1500 offer a slew of new towing safety features, but they do not include a blind spot warning system that sees the trailer and what's next to it.

The Ford F-150 and the Ram 1500 take slightly different approaches to this safety feature. Here are the specifics:


Though the Ram prompted us to look at blind spot warning with trailer coverage, the 2017 Ford F-150 was the first to offer it in this class. That means it's possible to find used F-150s with the feature.

Ford's system supports only conventional bumper-pull trailers, meaning it doesn't work with fifth-wheel or gooseneck trailers. If you connect a fifth-wheel or gooseneck trailer, the blind spot warning system automatically shuts off. Ford's system allows owners to use the steering wheel controls and the instrument panel screen to select the type of trailer, whether they want to adjust the blind spot system (selecting no turns it completely off) and the length of the trailer in 3-foot increments up to 33 feet. This information can be saved in individual trailer profiles so you don't have to enter it each time you use a particular trailer. The system works at speeds down to and more than 5 mph.

We should also note that any time a trailer is connected to the plug, the F-150's rear cross-traffic alerts automatically turn off. And if a trailer length is not provided, the blind spot warning system will shut off as well.


Ram added a blind spot monitor for trailers during its redesign of the 2019 half ton. It has one big difference from the Ford setup: This system can auto-detect the length of the trailer with just a few quick S turns. Ram says that in automatic mode, the system will use the blind spot sensors to detect the length of the trailer during a single 90-degree turn and once it starts going more than 6 mph. If the system can't determine the exact length of the trailer, it will default to the maximum length setting (almost 40 feet) until it does make a determination.

In addition to the length detection setting, there's also a manual setting to just leave the blind spot system at maximum length. These settings can be toggled in the Ram 1500's infotainment screen in the center console.

After spending time using both brands' blind spot monitoring systems, we don't think Ram's system is quite as granular as Ford's. Ram's system simply categorizes the trailer into one of four categories, basically in 10-foot increments up to a maximum length of 39.5 feet (which as far as length goes, beats the Ford by more than 6 feet). The Ford system can set trailer length in 3-foot increments.

The flexibility provided by this feature gives Ram and Ford a leg up on the competition since towing safely is a big selling point for many consumers and being able to merge safely is an area of concern. photos by Mark Williams and Brian Wong



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