The 'low air pressure' warning signal is required on:

All vehicles with air brakes.. Section 5.1: A low air pressure warning signal is required on vehicles with air brakes.

The 'low air pressure' warning signal is required on:

ANSWER BREAKDOWN
  • A. Incorrect. "Only vehicles built after 1990." is not correct. A low air pressure warning signal is required on vehicles with air brakes.
  • B. Correct. A low air pressure warning signal is required on vehicles with air brakes.
  • C. Incorrect. "Only buses." is not correct. A low air pressure warning signal is required on vehicles with air brakes.
  • D. Incorrect. "Only tractors." is not correct. A low air pressure warning signal is required on vehicles with air brakes.