U0418: Invalid Data Received From Brake System Control Module "A"
Another control unit is receiving messages from the Brake System Control Module "A", but the content does not make sense.
Normal risk
Have it checked soon. ABS, stability control and brake assistance may be limited.
Short answer · Can I keep driving with U0418?
Usually yes, with care. ABS, stability control and brake assistance may be limited. Have it checked soon.
What does U0418 mean?
Code U0418 means a control unit receives messages from the Brake System Control Module "A", but the values in them are out of range, frozen or inconsistent. The cause is often a fault inside that module or one of its sensors, missing calibration, wrong software or a voltage problem.
What the car does when the code is set
The receiving module ignores the invalid data. Functions that rely on it may be limited and warning lights can come on.
How the system works
Modules check incoming data for plausibility, for example value range and message counters. When the data is present but not plausible, they store an invalid data code naming the sending module.
Common symptoms
Possible causes
Listed without ranking. The cause on your car depends on make, engine and mileage — see the maker notes below.
- Fault in the module that sends the dataFor example a sensor fault inside or connected to that module.
- Network interferenceWiring problems can corrupt messages.
- Software mismatchModules with incompatible software versions.
- Low battery voltageUnstable voltage can corrupt data.
How it is diagnosed
- Read codes in the sending moduleCodes stored there often explain why its data is invalid.
- Check battery voltageMake sure supply voltage is stable.
- Check for software updatesA dealer can check for technical service bulletins and updates.
- Test the networkA workshop inspects the wiring if the data keeps arriving corrupted.
Questions about U0418
Is U0418 the same as a lost communication code?
No. Here the messages still arrive, but their content is wrong. The fault is usually in the sending module or its sensors rather than in the wiring.
Why does one module report another module’s data?
Modules share data; the receiving module notices when values are missing or implausible.