Powertrain, generic · Hybrid propulsion

P0C30 Hybrid/EV Battery Pack State of Charge High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0C30 is the counterpart of P0A7D: the battery controller finds that the state of charge of the high-voltage pack stays above its usable window. CARB requires hybrid OBD to flag a state of charge that can no longer be kept inside the manufacturer's range. GM's 2019 hybrid table 19OBDG01 describes the method: the SOC is checked once per drive cycle, the controller first allows time for the motor to draw the charge back down, then counts the distance driven with excessive SOC; if that share exceeds half of a trip longer than 50 km, at speeds above 15 km/h and pack temperature at least −10 °C, the code is stored as Type B, two trips. No other manufacturer documents it publicly. The car limits regeneration and charging to protect the cells, so braking feel and fuel economy can change.

Likely causes

Wrong SOC estimate from a drifting pack current or voltage measurement
Battery or hybrid control software not drawing the charge down as intended
Electric assist blocked by another fault, so the pack cannot discharge

Symptoms

  • MIL after two trips
  • Reduced or no regenerative braking
  • Changed brake pedal feel and higher fuel consumption

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,000
Time1–5 h

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

Parts involved

hv battery packbms

Related codes

P0A7DP0A7FP0A80P0A1FP0AFA

References: gsi.ext.gm.com, law.cornell.edu.