CDL Air Brakes TestAir Brake System PartsEasy
An anti-lock braking system (ABS) indicator light stays on after the engine starts. What does this signify?
- AThe traction control system is disabled.
- BThere is a malfunction in the ABS system.
- CThe vehicle's regular brakes have failed.
- DThe ABS is actively engaged due to slippery conditions.
Show answer & explanationAnswer & explanation
Correct answer: B. There is a malfunction in the ABS system.
If the ABS indicator light stays on after the engine starts, it indicates that the ABS system has detected a fault and is not functioning properly. While the regular brakes should still work, the anti-lock feature will not be available.
Why the other options are wrong
- A. While related, the ABS light specifically signals an ABS fault, not necessarily a traction control system issue, unless the vehicle combines these warnings.
- C. A persistent ABS light indicates a fault in the ABS, not necessarily a failure of the conventional brake system, which should still operate.
- D. The ABS light illuminates briefly during self-test and then turns off. It only stays on if there's a fault, not during normal operation.
ABS Indicator Light
The ABS indicator light (often amber) illuminates briefly when the ignition is turned on as a self-test and should then turn off. If it stays on, it signals a malfunction in the Anti-lock Braking System.
- Indicates an ABS fault, not conventional brake failure.
- Conventional brakes will still work.
- Should be addressed by qualified personnel.
Memory trick: Light on, something's wrong!