A2049012500 | Genuine Mercedes Benz® ABS Anti-Lock Brake Module Assy

An ABS (Anti-Lock Brake System) Module A2049012500 is an electronic control unit that helps prevent your wheels from locking up during hard braking. It works together with wheel-speed sensors and hydraulic valves to keep the vehicle stable and steerable—especially on slippery roads.

General Specifications

Purpose & Function

• Monitors wheel speed
  It uses data from sensors at each wheel to detect if any wheel is slowing down too quickly (about to lock up).

• Controls brake pressure
  If a wheel is about to lock, the module rapidly reduces and reapplies brake pressure through valves in the ABS hydraulic unit.

• Prevents wheel lock-up
  This keeps the tires gripping the road and helps maintain control.

• Communicates with other safety systems
  In many vehicles, ABS works with:

  • Traction Control (TCS)

  • Electronic Stability Control (ESC)

  • Brake Assist

Signs of a Bad Anti-Lock Brake Module

1. ABS Warning Light On

• The ABS light on the dashboard is the most common sign.
• It may stay on constantly or come on intermittently.

2. Brakes Lock Up Under Hard Braking

If the ABS module fails, the system may not prevent wheel lock-up, causing skidding or loss of steering control.

3. Increased Stopping Distance

You may notice it takes longer to stop the car, especially on wet or slippery roads.

4. Unresponsive Brake Pedal

A faulty module can cause the brake pedal to feel:

• overly hard

• spongy

• slow to respond

5. ABS Pump Running Constantly

If the module can’t correctly control the pump, you may hear it running all the time—even when it shouldn’t.

6. Random or False ABS Activation

The brakes may “pulse” or vibrate suddenly even when you’re braking lightly or on dry pavement.

7. Speedometer Problems

In some vehicles, a failing ABS module can cause the speedometer to behave erratically because they share wheel-speed data.

8. Traction Control or Stability Control Lights

ABS is linked to traction control and ESC. If the ABS module fails, these warning lights may also turn on.

5001 — N30/4 (ESP control unit) internal fault

5905 — Control unit N47‑5 (ESP control unit), internal fault 

5906 — Control unit N47‑5 (ESP control unit), internal fault

5944 — Control unit N47‑5 (ESP control unit), internal fault

5945 — Control unit N47‑5 (ESP control unit), internal fault

5962 — Component A7/3 (traction‑system hydraulic unit)

5964 — Component A7/3 (traction‑system hydraulic unit) 

About Detroit Diesel

Detroit Diesel is a leading American manufacturer of heavy-duty diesel engines, transmissions, and aftertreatment systems, primarily for the commercial trucking industry. Founded in 1938 and now a subsidiary of Daimler Truck North America, Detroit is best known for its DD Series engines — including the DD13, DD15, and DD16 — which power Freightliner and Western Star trucks.

Detroit also produces advanced technologies such as Detroit™ Axles, Detroit™ Connect telematics, and integrated powertrains, offering fleet operators improved fuel efficiency, uptime, and diagnostics. The company is headquartered in Detroit, Michigan, and continues to play a central role in modernizing emissions systems and performance standards in heavy-duty transportation.