2004 Dodge Ram 3500 Pickup Owner's Manual - Page 232

232 STARTING AND OPERATING WARNING! Both Anti-Lock Brake Systems contain sophisticated electronic equipment. It may be susceptible to interference caused by improperly installed or high output radio transmitting equipment. This interference can cause possible loss of anti-lock braking capability. Installation of such equipment should be performed by qualified professionals. Four-Wheel Anti-Lock Brake System - If Equipped This Anti-lock Brake System is designed to aid the driver in maintaining vehicle control under adverse braking conditions. The system operates with a separate computer to modulate hydraulic pressure to prevent wheel lockup and help avoid skidding on slippery surfaces. 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.