(NBC) - Federal regulators are investigating another vehicle made by General Motors for alleged safety problems.
The National Highway Traffic Safety Administration is investigating a report that the 2014 Chevy Impala's emergency braking system activated multiple times without warning.
A driver says that in one instance, the Impala was traveling 40 mph when the brakes activated.
The car was struck in the rear by another vehicle. No injuries were reported.
Federal regulators are trying to determine if the alleged defect is widespread.
The investigation is not related to GM's recent recall of 2.6 million older model Chevrolet and other cars for defective ignition switches.
An estimated 60,580 Impalas of the 2014 model year are on US roads.