Chassis, generic

C0592 Brake Booster Motor B Phase U-V-W Current High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0592 reports excessive current in the second motor or second winding system, B, of an electric brake booster. No manufacturer publishes it in this sense; the number appears only in GM's keyword list PIP5094 for 2014 and older vehicles, from an earlier numbering. Side B exists in redundant layouts such as the Hyundai Mobis dual-winding booster motor, where two power modules with six MOSFETs each drive one winding and the healthy module takes over the full current command once the other is diagnosed as failed. Overcurrent on such a stage is caught by MOSFET drain-source monitoring and shunt amplifiers, as offered by TI's DRV8343-Q1. GM's side A limits (above 20 A leakage, 38 A offset) show the order of magnitude. Expect assist on side A only or reduced.

Likely causes

Shorted or leaking transistor in power module B
Insulation fault in winding system B
Measuring offset of the side B current sensing

Symptoms

  • Brake assist warning, possibly weaker or slower assist
  • Brake or ABS warning lamp on

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€200–3,000
Time1–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

brake booster motor bmotor phase wiring

Related codes

C0593C0590C05AFC0583

References: patents.google.com, ti.com, static.nhtsa.gov.