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P0C0A

Drive Motor B Phase U-V-W Circuit High

The drive motor B phase U-V-W output reports a circuit high condition. The drive motor's position, current and temperature are watched continuously; a fault here downgrades the inverter to a safe operating point or triggers torque reduction.

  • Check engine light: Yes
  • Emissions related: No
  • Repair difficulty: hard

Symptoms

  • EV/hybrid system warning light on
  • Reduced motor power or torque
  • Possible limp mode or vehicle shutdown

Common causes

Ordered by how often each turns out to be the cause.

  • Phase wire shorted to high voltageCommon
  • Open motor windingPossible
  • Connector pins corroded - high contact resistanceLess likely

Parts involved

  • Drive Motor B Phase Uvw
  • Drive Motor B Inverter

P0C0A is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.