General Motors is recalling more than 638,000 trucks and SUVs to address a defect that can cause sudden and unexpected braking.
The issue stems from the programming of a system designed to protect the driveline from conditions that occur when wheel speeds vary significantly from one wheel on an axle to the other. This system relies on speed sensors that monitor each wheel.
If one of these sensors fails, the computer can interpret that as a wheel stopping, which will trigger a braking command on the opposite wheel. This can cause the vehicle to pull suddenly in the direction of the braking wheel, catching drivers off guard and potentially resulting in a collision.
GM says the issue should only present itself in 2015-2020 Chevrolet Suburban, Tahoe, and GMC Yukon, and 2014-2018 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles configured with the 5.3-liter V-8, a 3.08-ratio rear axle and four-wheel drive. While this may seem like a fairly narrow set of criteria, it is one of the more common configurations for several of the affected models.
Fortunately, the fix is relatively simple. All that is required is a software update to the Electronic-Brake Control Module, which should not prove to be an extensive inconvenience. GM has not yet provided NHTSA with a timetable for providing the updated software to dealerships or notifying owners, but that information should be forthcoming.
This recall overlaps with several models subject to another campaign brought on by faulty components in the vehicles' seat belt retractors. That recall also covers several sedans and hatchbacks, but was limited to just 16,000 vehicles.