U0129
Lost Communication with Brake System Control Module
This code indicates lost communication with brake system control module. It relates to the powertrain / generic and may affect performance, emissions, or drivability depending on the exact failure.
Lost Communication with Brake System Control Module
Common causes
- medium
Faulty sensor or actuator
The component monitored by this code may be worn, failed, or reading out of range.
Typical part cost: $100-400
- medium
Wiring or connector issue
Corroded, damaged, or loose connections can cause circuit or signal faults.
Typical part cost: $100-400
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does U0129 mean?
U0129 means "Lost Communication with Brake System Control Module". It is a generic OBD-II code that points to a fault in the powertrain / generic.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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