Five Advantages Of The Sierra HD’s New Digital Steering Assist System
Advanced technology results in steering that’s light and easy in the parking lot, confident on the open road, and easier than ever to use.
Working hard doesn’t have to feel hard – in fact, the GMC Sierra HD’s Digital Steering Assist system makes driving and maneuvering a heavy-duty pickup easier.
The variable-effort hydraulic power steering system, standard on most Sierra HD double and crew cab models equipped with SLE, SLT, All Terrain, or Denali trim levels, proactively adjusts power steering assist levels in order to increase confidence while on the open road
“Modern electric power steering systems offer a lot of flexibility when it comes to changing the steering weight and effort,” says Christopher Bither, vehicle performance/ dynamics engineer for the Sierra heavy-duty pickup truck. “Digital Steering Assist is unique as it allows us to offer a similar range of tuning possibilities in the Sierra HD, yet retain the robust durability of a conventional heavy-duty hydraulic system.”
Here are five advantages you will feel when you take the wheel of a Sierra HD pickup truck equipped with Digital Steering Assist:
Speed-Adaptive: Power steering assist is often tuned to provide enough assist to make low-speed maneuverability – in parking lots, for example – where resistance is greater. While a light steering weight is great in that situation, it can feel too light once a vehicle is up to speed, and might require constant correction.
Digital Steering Assist delivers the best of both worlds. A controller connected directly to the steering gear actively measures vehicle speed, steering wheel position, and steering gear pressure and can adjust the amount of effort a driver needs to input depending on the situation. At low speeds, steering effort is 20% lighter than a comparable 2015 Sierra HD, while at higher speeds, the steering system provides a heavier feel, which provides better stability and consistency.
Tailored for Tow/Haul: A truck loaded with cargo or pulling a large, heavy trailer handles much differently than an empty truck because of the added weight. A steering wheel that normally feels light and easy to turn may require greater effort once the truck is laden. Sierra’s Digital Steering Assist solves that: When the driver pushes the Tow/Haul switch -- which also adjusts transmission tuning -- Digital Steering Assist responds by increasing low-speed assist and reducing static steering effort another 10%.
Return to Center: Traditional heavy-duty steering systems often required a fair amount of driver input to bring the steering wheel back to center, even with power assist. Because Digital Steering Assist can actively adjust assist levels, it can greatly reduce the amount of effort required to center the steering wheel, which can be beneficial when maneuvering in small parking lots or other tight quarters.
Counteracts Road Pull: Roads with significant crowning can prove tiresome, as even a vehicle with perfectly-aligned suspension will inevitably pull to one side. Instead of forcing the driver to constantly dial in steering to counteract for this pull, Digital Steering Assist can recognize the situation and proactively assist.
“Digital Steering Assist will recognize when the driver is applying a certain amount of pressure offset over an extended period of time and then keep the pressure value there,” says Bither. “Instead of the driver constantly holding the truck in a straight line, the steering gear does it for you.”
Variable Flow Pump: In addition to varying the weight and effort of the steering system, Sierra’s Digital Steering Assist system goes a step further by utilizing a variable-output hydraulic power steering pump. When the system is under a light load – like on a long, straight stretch of highway, for example -- the pump’s output can be scaled back, reducing engine load and improving efficiency.
Digital Steering Assist is one of many enhancements incorporated into the Sierra HD pickup truck. New HID projector-beam headlamps, complete with GMC signature LED lighting, is now standard on all Sierra HD models. A remote locking tailgate is available for added convenience. The gooseneck/ 5th wheel prep package adds a frame-mounted hitch platform, a bed-mounted trailer harness, and a spray-in bed liner.
Inside, wireless phone charging is available in Sierra pickup trucks equipped with a fixed center console, while updated IntelliLink infotainment systems offer expanded connectivity, including Apple CarPlay and, on select models, Android Auto.