Powertrain, generic · Hybrid propulsion

P0C03 Drive Motor B Current Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0C03 indicates that drive motor B draws less current than the controller expects for the requested torque. It is the low counterpart of P0C04 and the motor B twin of P0C00. No manufacturer documents this exact code publicly, and the GM hybrid tables use only P0C04 and P0C08 for motor B. CARB requires hybrids to monitor electric motor performance. Low current typically comes from a high-resistance cable joint, an interrupted winding path or an inverter stage that does not switch; a single missing phase is reported by GM as P0C08. In practice motor B delivers little or no torque, a warning lamp lights up and the system may fall back to the other motor or the engine.

Likely causes

High-resistance or loose three-phase connection of motor B
Inverter power stage for motor B not delivering current
Open or damaged winding in drive motor B

Symptoms

  • Weak or missing torque from motor B
  • Warning lamp for the hybrid or electric drive
  • Reduced performance or limp mode

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–5,000
Time1–8 h

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

Parts involved

drive motor bdrive motor b inverter

Related codes

P0C02P0C04P0C00P0C08P0BFEP0A79

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov.