Home › CDL Practice Tests › Air Brakes Questions › Question 198
What should a tractor ABS lamp normally do when the ignition is first turned on?
- A.Stay on for the entire trip even when the system is healthy
- B.Come on briefly for a bulb and system check, then go out if no fault is detected
- C.Never come on at any time
- D.Flash rapidly whenever the brakes are applied
Correct answer
B. Come on briefly for a bulb and system check, then go out if no fault is detected
Why
The startup illumination proves the bulb works and the controller is running its self-check. A lamp that never lights cannot warn you later, and a lamp that stays on is reporting a malfunction.
Manual topic: Air Brakes - ABS · From the Air Brakes practice bank (AB-198).