U0418Invalid Data Received From Brake System Control Module A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U0418 says a node rejects the content of frames from brake system control module A, on many cars the unit that combines ABS, stability control and brake boost. GM's 2025 tables are detailed: the engine controller tests brake status signals for bad counters, protection values or checksums, 8 faults in 18 checks give Type A with MIL after one trip; the TCM runs the same test as Type B, the BCM demands 15 bad of 16, and the front camera rates its check Special Type C and only disables adaptive cruise. Saab's 9-5 list adds sub-types 71, 72 and 74. FCA notes for the 2021 Jeep Cherokee 2.4 L that U0418 may set falsely below 10 V and reflashes the PCM (18-078-22); BrightDrop 24-NA-107 forbids repairs for it on the Zevo 600. U0129 is lost contact, U0318 software.
- What you may notice
- Check engine light
- Adaptive cruise, stop-start or driver assistance unavailable
- Brake or stability warning in the cluster
- Likely causes
- LikelyLow battery voltage (below about 10 V) during start or standstill
- PossibleEngine or transmission controller software reacting too sensitively; update available
- PossibleLoose connector or harness fault disturbing the chassis bus
- RareBrake system control module internally faulty
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €2,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.