Traveling on the highway at 70 mph the rear wheels (brakes) locked up nearly causing a collision. I found a couple of recalls notices for 2020 Chevy Silverado 1500, but nothing posted for 2019 Chevy Silverado. The vehicle was taken immediately to the dealership for evaluation and repair. The tow/haul mode light blinked on and then off. At no time was the tow haul mode manually engaged. My understanding is the vehicles Electronic Brake Control Module (EBCM) software could have an error that should be covered under a recall. Upon inspection and repair the dealership found codes for the brake system control module lost communication with multiple modules and found low voltage codes. They replaced the battery and updated the BSCM. I believe Chevrolet should extend the recall to 2019 models and hopefully this report will cause action to be taken and prevent accidents in the future.