Chassis
generic / SAE
C0585
Brake Booster Motor B Phase U-V-W Circuit High
Brake booster motor B phase voltage above expected range. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
SystemChassis
Typegeneric / SAE
GroupC0
Range / number5 / 85
Possible causes
- Phase shorted to power high
- Connector pins corroded - high contact resistance low
- Supply wire pinched against B+ source low
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 400–2500 €
- Estimated time: 2–6 h
- Component: brake booster motor b
- Component: motor phase wiring
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012