C0584Brake Booster Motor B Phase U-V-W Circuit Low
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- C0584 means a phase of booster motor B is held too low – shorted to ground, a lower transistor that will not switch off, or a driver whose gate supply has collapsed. No manufacturer publishes the code in its booster meaning; it shows up only in GM's older keyword list (PIP5094), where the number belonged to another system. Gate drivers such as TI's DRV8343-Q1 test every phase for a short to ground while the bridge is disabled, and the DRV8305-Q1 reports when its charge pump falls too far below the motor supply. With two independent winding systems, as in the Hyundai Mobis patent, a fault in one system must not pull down the other, so the module isolates side B and, where the design allows, keeps braking assist going on side A.
- What you may notice
- Brake system warning and possibly reduced assist
- Driver assistance braking functions may be limited
- Likely causes
- PossiblePhase lead of side B shorted to ground or housing
- PossibleLower transistor of power module B shorted
- PossibleGate-driver supply of channel B too low
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €2,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.