The yellow ABS malfunction lamp indicates that ABS control may be lost at one or more wheels. What should you do?
Correct answer: B. – Drive normally using the regular brakes, but have the ABS serviced soon
A malfunctioning ABS does not mean the bus has lost its regular brakes. Continue to drive and brake normally, while recognizing that ABS assistance may be unavailable. The system should be inspected and serviced soon, and the malfunction is not a reason to drive faster or less carefully.
Source: Virginia Commercial Driver’s License Manual – Modernized Testing System — § 10.6.4, “Braking if ABS is Not Working”

