84025048 | Genuine GM® Anti-Lock Brake Module For 2017 Express 2500, 3500

1. Compatible Vehicles

• 2017 Chevrolet Express 2500 (3/4-Ton Cargo & Passenger Vans)

• 2017 Chevrolet Express 3500 (1-Ton Cargo, Passenger & Cutaway Vans)

• 2017 GMC Savana 2500 (3/4-Ton Cargo & Passenger Vans)

• 2017 GMC Savana 3500 (1-Ton Cargo, Passenger & Cutaway Vans)

2. Compatible Engines

This module covers all engine offerings for the 2017 model year:

• 2.8L Duramax I4 Turbo-Diesel

• 4.8L Vortec V8 Gasoline / Flex-Fuel

• 6.0L Vortec V8 Gasoline / Flex-Fuel / CNG

• 6.6L Duramax V8 Turbo-Diesel

1. What is it?

The module functions as the electronic computer for the vehicle's hydraulic braking assembly. It continuously processes wheel speed signals from all four wheels to prevent wheel lockup, skidding, and loss of control during emergency braking maneuvers or driving on low-traction surfaces (rain, snow, ice).

2. Integrated Vehicle Safety Systems

This module directly controls and coordinates three critical safety networks:

• Anti-Lock Braking System (ABS): Rapidly pulses hydraulic fluid to individual wheel brakes to maintain tire traction during hard stops.

• StabiliTrak® (Electronic Stability Control): Detects vehicle lateral skids and automatically applies selective braking to assist the driver in steering back on course.

• Traction Control System (TCS): Reduces engine power or applies wheel braking when wheel slip is detected during acceleration.

1. Warning Lights on the Instrument Cluster

The most immediate indicator is the permanent illumination of yellow or amber dashboard warning lights:

• ABS Warning Light stays lit continuously.

• Traction Control / StabiliTrak Light stays turned on.

• Driver Information Center (DIC) messages such as "Service StabiliTrak" or "Service Brake System".

2. Diagnostic Trouble Codes (DTCs)

Scanning the brake system with an OBD-II scan tool will typically reveal specific C-series and U-series fault codes:

• C0265 / C0550: Internal Electronic Brake Control Module (EBCM) hardware/circuit failure.

• C0035 – C0050: Wheel speed sensor circuit fault codes (often caused by cracked internal solder joints inside the EBCM board rather than a bad sensor).

• U0121: Lost Communication with Anti-Lock Brake System (ABS) Control Module.

3. Unresponsive Anti-Lock Braking (Wheel Lockup)

When the module shuts down due to internal electronic shorts, the vehicle reverts to standard hydraulic braking. Under sudden or hard braking—especially on slippery roads—the ABS will not activate, causing the wheels to lock up, skid, and flat-spot the tires.

4. Continuous ABS Pump Running (Drain on Battery)

A failed pump relay circuit or shorted transistor on the circuit board can cause the ABS hydraulic pump motor to run constantly—even with the key turned off and removed. This results in a completely dead battery overnight.

5. Spongy, Unresponsive, or Pulsating Brake Pedal

Internal valve driver failures within the electronic unit can cause unpredictable hydraulic pressure modulation, resulting in a unusually soft or spongy pedal feel, or erratic chatter/pulsation during normal stopping conditions.