United States 79V094000
General Motors, LLC
The problem
THE INVOLVED VEHICLES FAIL TO MEET FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 121, "AIR BRAKE SYSTEMS", IN REGARD TO INCORRECT PLUMBING IN THE LOW AIR PRESSURE WARNING SYSTEM. AS A RESULT, A LOW AIR PRESSURE CONDITION IN THE REAR BRAKE AIR SUPPLY WILL NOT ACTUATE THE WARNING SYSTEM. THE AUDIBLE ALARM WOULD NOT FUNCTION AND THE DRIVER WOULD NOT BE WARNED OF A BRAKE MALFUNCTION.
What owners should do
THE LOW AIR PRESSURE WARNING SYSTEM WILL BE INSPECTED AND CORRECTED, IF NECESSARY, WITHOUT CHARGE.
Units 22