C0585Brake Booster Motor B Phase U-V-W Circuit High
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- C0585 stands for a phase of booster motor B reading too high, for instance a lead shorted to battery positive or an upper transistor stuck on. The number had another use on older GM-platform cars: on the 2011 Saab 9-5 it identified the left rear damper actuator of the adaptive suspension. In its booster meaning no manufacturer publishes it. The checks required mirror those for C0581 on side A – offline short-to-supply tests and drain-source voltage monitoring as in TI's DRV3245Q-Q1. Redundant drives then isolate the faulty side: Kollmorgen's early patent on redundant windings already shared the torque among the healthy winding sets, and in the Hyundai Mobis design the remaining power module takes over the whole current command.
- What you may notice
- Brake system warning lamp
- Reduced or switched-off electric assist
- Likely causes
- PossiblePhase lead of side B shorted to battery voltage
- PossibleUpper transistor of power module B shorted or stuck on
- RareCode read on an older GM-platform vehicle where C0585 belongs to a damper actuator
- 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.