What must a heavy truck driver do immediately if the pneumatic brake system low-pressure warning buzzer sounds and the red warning lamp illuminates while driving on a highway?

1. Activate hazard lights, safely maneuver to the hard shoulder immediately, stop before spring brakes lock wheels, and place a warning triangle
2. Ignore the buzzer and continue driving to the destination as long as the engine runs smoothly
3. Accelerate to build up ram-air pressure in the intake manifold
4. Disconnect the buzzer wiring under the dashboard and maintain normal highway speed