2022 Toyota Tacoma
Traction buttons have become a lot more complicated than they used to be. (Photo: Courtesy Toyota)

Everything You Ever Wanted to Know About Your Truck’s Traction Settings

Your 4x4’s dashboard displays a bunch of buttons that you probably don’t know how to use. Here’s your guide.

2022 Toyota Tacoma

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This August, I test drove an array of 2022 Toyota Tacomas above Keystone, Colorado, which prompted two epiphanies. One was that these peaks are eye-poppingly beautiful (duh). The other was that traction buttons have become a lot more complicated than they used to be, when settings were limited to just 4WD high and low.

Today, even basic trucks come with increasingly sophisticated traction-control options. Case in point: the Trail Edition that I drove had always been a soft-adventure Tacoma model that looked rugged enough for state park campgrounds—but lacked the ground clearance and traction features you’d want for real off-road travel. For 2022, however, the Trail Edition gets underbody skid plates, better clearance (a 1.1-inch front lift and half-inch rear lift to improve the approach angle to 34 degrees and departure angle to 23.6 degrees), and a locking rear differential.

That rear locker, which enhances traction in uneven terrain (more on that later), is now a standard feature on this formerly unambitious truck, and the button taunted me as I negotiated the rock-strewn roads linking Georgia Pass and Montezuma. What situations called for a rear locker? Should I just turn it on and leave it on, or were there disadvantages to having it on all the time? How about that particularly ledgy section where I lost traction: Would engaging the rear locker have helped me to clear it?

I realized that there was a fair bit that I didn’t know about this traction option, and when I swung into the driver’s seat of Toyota’s flagship TRD Pro, I encountered even more buttons for the Crawl Control and Multi-Terrain Select (MTS) features. I’ve had some practice with these types of functions, available not only on Toyotas but from various manufacturers including Jeep, Ram, Ford, Land Rover, and others. Such traction buttons are proliferating across vehicles’ dashboards because electronic traction control (ETC) is becoming more mainstream. Range Rover debuted the first iteration in 1992, and now, 4x4s commonly integrate “intelligent” systems that use wheel sensors to relay data about wheel slippage to a computer that responds with optimal braking, torque, and transmission shifting. Expert offroaders sometimes dismiss such systems as “nannies.” But many ordinary drivers don’t even understand what they do or how they work.

“Some people who come to my camps just want to find out what all those buttons do,” says off-road driving instructor Charlene Bower. Not knowing makes it hard to exploit those capabilities in the truck you just bought, and it certainly makes it difficult to decide what traction features you need and want in your next vehicle.

Having a guru like Bower tell you where and how to use those buttons in real-world situations is better than anything you’ll find on YouTube (where you can watch videos of people using Toyota’s Crawl Control feature to dig themselves out after sinking their frames into dunes). But not everyone will hire a driving instructor, so I asked Bob Wohlers, an off-road trainer and founder of Offroad Safety Academy (which also tests 4×4 systems for auto manufacturers) to help me compile this guide to understanding and using common traction-control features. It doesn’t substitute for hands-on practice with Wohlers (or for reading his books, which are the bibles of off-roading) but it does explain what traction buttons do and gives some basics on how to use them.

Terrain Select

Top-end 4×4 models commonly give drivers a choice of terrain settings. Toyota has a Multi-Terrain Select button that lets you scroll through five modes (Mud and Sand, Loose Rock, Rock and Dirt, Mogul, and Rock). On Ford Raptors, the Terrain Management feature offers seven settings, including Baja (for high-speed off-roading) and Rock Crawl (for slow-speed maneuvers over large obstacles). The Ram TRX has three off-road modes (Mud/Sand, Rock, and Baja). Jeep calls its system Selec-Terrain and includes Jeep’s options are Snow, Sand, Mud, Rock, and Auto modes.

All use electronic traction control systems to monitor wheel spin and respond with the optimal brake pressure, power distribution, and transmission gearing, which differs depending on terrain type. Sand, snow, or mud—what Wohlers refers to as “compression terrain”—call for more wheel spin to maintain or regain traction. Snow settings generally balance the torque between the front and rear wheels or prioritize the front with a 60/40 distribution. Sand settings might devote as much as 100 percent torque to the rear wheels to maintain momentum through deep, loose surfaces. On rock, the computer delivers more brake pressure to keep wheels from spinning out on ledges or boulders.

All ETC systems rely on some wheel slip to cue the computer to a problem. That means drivers in off-road situations shouldn’t automatically take their foot off the accelerator at the very first sign of a loss of traction, which is the first thing you should do if your vehicle doesn’t have this kind of aid. However, the time required for the computer to diagnose a situation and respond to it varies by manufacturer and vehicle age.

“When they were first invented, [ETC systems] were very reactive,” says Wohlers, meaning that they had to wait for the vehicle to lose traction before they could assess the problem and issue a fix. Thus my 2006 Toyota Tundra takes a couple of seconds (which feels like an eternity) to restore traction to a wheel that’s slipping on rock. But the sensors have gotten better since then, says Wohlers, who finds that some systems (such as the one used in the latest Land Rover Defenders) respond so quickly that “you almost can’t feel it working,” he says. “The wheel barely has to spin before the computer kicks in. It’s still reactive, but it just responds so fast.”’

Downhill Assist

This button typically depicts a speedometer icon above a vehicle pointed downhill—and it keeps a vehicle tracking straight as it negotiates a loose descent. Gravelly rocks, sand, mud—all these conditions increase the possibility that the vehicle will drift sideways, so this setting detects yaw angles and automatically brakes the wheels on the inside of the slide to straighten the car. “It’s tremendous physics manipulation by the software,” says Wohlers.

Because it’s intended for slow-speed situations, this feature is typically available only when the vehicle is in 4WD low. It cues the computer to apply plenty of engine compression braking rather than relying on lots of wheel braking, which could induce a skid on loose surfaces.

Off-Road Cruise Control

“Each manufacturer calls this something different, which makes it really hard to teach people about it,” says Wohlers. Toyota named its version Crawl Control; Ford Raptors and Rangers have Trail Control. “But they’re all a cruise control for low speed over uneven terrain, and they all work the same,” Wohlers continues.

These settings let a vehicle’s computer do all the braking and acceleration necessary to maintain your desired speed over rough road. “The benefit is that you can focus all your attention on vision, and picking a line,” says Wohler, “And that’s the Zen of off-roading.”

These features are known for being loud and clunky—it can be disconcerting at first to hear and feel those automatic inputs while you’re steering—but forthcoming models appear to be addressing this common complaint. Early reviews of the 2022 Toyota Tundra, for example, note that its Crawl Control function is startlingly quiet.

Sway Bar Disconnect

A vehicle’s sway bar keeps the body level and stable around corners, but it limits the wheels’ articulation, something that rock-crawlers rely on to let one wheel sink into a rut or float over a boulder. Disconnecting the sway bar lets the wheels on one axle rise and fall independently, rather than as a pair. “Wheels in the air do you no good,” explains Wohlers. “It’s always better to have all your wheels on the ground.”

Electronic sway bar disconnect buttons are found on Jeep Rubicons, Ram Power Wagons, and the 2021 Ford Broncos. Toyota doesn’t offer an electronic disconnect, but drivers who want that feature can invest in aftermarket modifications to their sway bar ends and brackets so they can be disconnected manually.

Tight Turn Assist

Another emerging feature (available on the 2021 Ford Bronco) is a button that cues the vehicle to use torque vectoring on the rear axle to make an incredibly tight turn. Rivian is developing something similar with its K-Turn, which locks one or both of the rear wheels so that the front can pivot the car through a 180-degree reversal of direction (except with the Rivian, the feature will engage automatically, not with the push of a button).

Locking Differentials

This feature isn’t part of a vehicle’s ETC system. Instead, it’s a mechanical lock that changes the way wheels behave on their axle but is definitely worth mentioning in this context.

First, a physics lesson: cars use differential gearing to let the outside wheels spin faster, so it can cover a longer arc of travel than the inside wheel. It makes for smooth turns on pavement, but it creates problems in off-road terrain that’s rocky or rutted—because if one wheel gets suspended off the ground, all the engine power goes to that zero-traction wheel. The result can be a wheel that’s spinning furiously in midair, while the wheel that’s actually contacting the ground gets zero torque.

Sand is another scenario where differentials become a liability. “Maybe you’re on a beach where some sand has higher traction because it’s a little wet, but the wheels on the drier sand start to spin out because they suddenly get all the energy,” Wohlers explains. That’s why some Baja 1000 racers (who encounter lots of sand) actually weld their axles so both wheels always spin at the same rate.

Locking differentials give off-roaders the same benefit, except it’s temporary. The button slides a cuff over the differential to “lock” it and send torque to both wheels equally—so that if one wheel loses traction, the others continue to get enough torque to keep rolling.

Only a few vehicles (including the Ram Power Wagon and Jeep Rubicons) come with front and rear lockers; rear-only is more common. Wohlers loves them for hill climbs because they let him maintain momentum without relying on excessive speed. He also relies on this feature in cross-axle traction scenarios where diagonal wheels have traction but the opposite diagonal doesn’t.

That’s why a locking rear differential is Wohlers’ favorite feature, and if you can choose just one button, this should be it. “Lockers are still the pinnacle of traction aids,” he says. “They’re still the best.”

Lead Photo: Courtesy Toyota