An ABS indicator lamp on a commercial vehicle comes on and stays on after the engine starts. What does this usually signify?

Question: An ABS indicator lamp on a commercial vehicle comes on and stays on after the engine starts. What does this usually signify?

Answer options: ✅ A malfunction within the Anti-lock Braking System.

• The ABS system is currently active and preventing wheel lock-up.
• The parking brake is engaged, and the ABS system is on standby.
• Insufficient air pressure in the service brake lines for ABS operation.

Correct answer: A malfunction within the Anti-lock Braking System.

Explanation: If an ABS indicator lamp illuminates and remains lit after engine start-up, it typically indicates a fault or malfunction within the Anti-lock Braking System itself. This means the ABS may not function as intended during an emergency stop, but the base air brake system should still operate.