U0129 on 2020 Chevrolet Corvette (Stingray 1LT, Stingray 2LT, Stingray 3LT) — Lost Communication With Brake System Control Module A
1 vehicles · 1 makes
How to diagnose and fix U0129: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Chevrolet Corvette · 2020–2020
GM recalled 2020 C8 Corvettes after finding that sensor contamination inside the electronic brake boost (eBoost) module can interrupt communication within the braking system. The C8 uses an electronically boosted brake system rather than a conventional vacuum booster, so when the module drops out the driver loses power assist and must apply substantially higher pedal effort to stop the car. NHTSA identified the consequence as increased crash risk. Owner complaints filed against the 2020 car back this up in blunt terms, with one owner reporting the brakes did fail and that it was difficult to stop the vehicle. Notification and remedy for campaign 20V588000 began December 9, 2020.
Common Symptoms
- Brake warning lights illuminate on the cluster
- Hard brake pedal requiring much greater effort
- Reduced braking performance and longer stopping distances
- Loss of brake assist without warning
How to Fix
Verify your VIN against campaign 20V588000 at nhtsa.gov/recalls or through a Chevrolet dealer; the remedy is free replacement of the electronic brake boost module. If the brake warning light or a 'Service Brake Assist' style message appears while driving, treat it as an immediate loss-of-assist warning: the brakes will still stop the car mechanically but need far more pedal force and far more distance. Increase following distance dramatically, avoid highway speeds, and get the car to a dealer without delay. Do not clear the fault and continue driving on the assumption it is a sensor glitch — the recall exists because the interruption is intermittent and repeats.
Sources for this issue (2)
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U0129 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does U0129 mean?
U0129 stands for "Lost Communication With Brake System Control Module A." Sets when a module loses data-bus communication with Brake System Control Module 'A' (integrated brake/booster controller) and no longer receives its expected messages.
What are the most common causes of U0129?
The most common causes of U0129 are: Open or shorted bus wiring to the brake system module, Corroded or loose connector / poor ground, Blown fuse / lost power feed, Low battery voltage, Failed brake system control module. The specific cause varies by vehicle.
How much does it cost to fix U0129?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by U0129?
Au7o has documented U0129 across 1 vehicle models from 1 manufacturers: Chevrolet.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.