2007 Dodge Ram 1500 Pickup Owner's Manual - Page 342

342 STARTING AND OPERATING The system's pump motor runs during an ABS stop to provide regulated hydraulic pressure. The pump motor makes a low humming noise during operation. This is normal. When you are in a severe braking condition involving use of the Anti-lock Brake System, you will experience some pedal drop as the vehicle comes to a complete stop. This is the result of the system reverting to the base brake system and is normal. Engagement of the Anti-lock Brake System may be accompanied by a pulsing sensation. You may also hear a clicking noise. These occurrences are normal, and indicate that the system is functioning. ABS Warning Light The Anti-lock Brake System includes an amber warning light. When the light is illuminated, the Anti-lock Brake System is not functioning. The system reverts to standard non-anti-lock brakes. WARNING! Pumping of the anti-lock brakes will diminish their effectiveness and may lead to an accident. Pumping makes the stopping distance longer. Just press firmly on your brake pedal when you need to slow down or stop.