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C056DCriticalChassis

C056D on 2020-2024 GMC Sierra 3500HD — Electronic Brake Control Module Internal Fault (manufacturer-specific)

1 vehicles · 1 makes

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Most Reported On

2020-2024GMC Sierra 3500HD

C056D is an OBD-II diagnostic trouble code meaning “Electronic Brake Control Module Internal Fault (manufacturer-specific).” C056D is a manufacturer-specific chassis code (frequently seen on GM vehicles) that generally indicates an internal hardware/electronics failure within the electronic brake control module (EBCM)/ABS assembly. When the module's own self-test detects a fault it cannot recover from, it disables ABS, traction control, and stability control and commonly triggers the 'Service StabiliTrak'/'Service Traction Control' messages. Because the fault is internal to the module, the usual repair is reprogramming or replacing the ABS/EBCM unit after confirming wiring and power/ground are good. Conventional braking still functions while the electronic aids are offline. This code is most commonly reported on 2020-2024 GMC Sierra 3500HD.

On This Page

  • Common Causes
  • Vehicles (1)
  • Related Codes
  • FAQ
  • Sources (4)
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Common Causes

1Internal EBCM/ABS module hardware failure
2Corroded or damaged module connector/pins
3Poor power or ground to the ABS module
4Low battery voltage or charging system issues
5Water intrusion/corrosion in the module
6Module software/calibration corruption
7Wiring faults at the brake module connector

Diagnostic Tools

To diagnose C056D, you'll need an OBD-II scanner. Here are our recommendations at every price point.

Budget Pick$10–$20

ANCEL AD310 Classic OBD-II Scanner

by ANCEL

A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).

  • Read & clear engine codes
  • View freeze frame data
  • I/M readiness status
  • No batteries or app needed
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Best Value$90–$120

BlueDriver Pro Bluetooth Scanner

by BlueDriver

Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.

  • Enhanced diagnostics (ABS, SRS, transmission)
  • Repair Reports with verified fixes
  • Smog check readiness
  • Free app (iOS & Android)
Check Price on Amazon
Advanced$180–$230

LAUNCH CRP123X OBD-II Scanner

by LAUNCH

A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.

  • Engine, transmission, ABS, SRS diagnostics
  • Live data stream & graphing
  • AutoVIN for vehicle identification
  • Free lifetime updates via Wi-Fi
Check Price on Amazon
Professional$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

by Autel

Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.

  • All-system diagnostics (25+ modules)
  • Bi-directional control & active tests
  • Oil reset, EPB, BMS, TPMS, injector coding
  • 7-inch touchscreen with Android OS
Check Price on Amazon

As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.

Vehicles Affected (1)

GMC C056D page →
Sierra 3500HDCritical

Electric power steering (EPS) assist loss / reduced assist warnings (new body style)

2020-2024120 reports

Related Codes (8)

C0561System Disabled / Invalid Serial Data ReceivedC0562Manufacturer-Specific Chassis Code (definition reserved/varies)C0569Manufacturer-Specific Chassis Code (GM: System Configuration Error)C0031Left Front Wheel Speed Sensor CircuitC0034Right Front Wheel Speed Sensor CircuitC0036Left Front Wheel Speed Sensor CircuitC0037Left Rear Wheel Speed Sensor CircuitC0038Left Rear Wheel Speed Sensor Circuit

FAQ

What does C056D mean?

C056D stands for "Electronic Brake Control Module Internal Fault (manufacturer-specific)." C056D is a manufacturer-specific chassis code (frequently seen on GM vehicles) that generally indicates an internal hardware/electronics failure within the electronic brake control module (EBCM)/ABS assembly. When the module's own self-test detects a fault it cannot recover from, it disables ABS, traction control, and stability control and commonly triggers the 'Service StabiliTrak'/'Service Traction Control' messages. Because the fault is internal to the module, the usual repair is reprogramming or replacing the ABS/EBCM unit after confirming wiring and power/ground are good. Conventional braking still functions while the electronic aids are offline.

What are the most common causes of C056D?

The most common causes of C056D are: Internal EBCM/ABS module hardware failure, Corroded or damaged module connector/pins, Poor power or ground to the ABS module, Low battery voltage or charging system issues, Water intrusion/corrosion in the module, Module software/calibration corruption, Wiring faults at the brake module connector. The specific cause varies by vehicle.

How much does it cost to fix C056D?

Repair costs vary widely depending on the root cause and vehicle.

Which vehicles are affected by C056D?

Au7o has documented C056D across 1 vehicle models from 1 manufacturers: GMC.

Sources (4)

  • ForumSilveradoSierra: Electric Power Steering
  • mediaZehl & Associates: 800,000 Chevrolet Silverado and GMC Sierra Trucks for Faulty Power Steering
  • mediaAboutLawsuits: GMC Sierra, Chevy Silverado Recall Issued Due to Electric Power Steering Problems
  • ForumSilveradoSierra: Loss of all power steering 2019 sierra elevation 5.3

Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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