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P2C87 Powertrain

Hybrid/EV Battery Voltage External Isolation Warning

The hybrid control module detects an early-warning external isolation degradation. Pre-failure indicator for HV cable insulation against chassis.

Affected components

  • Hv battery
  • Hv wiring
  • Isolation monitor

Common causes

  • High likelihood: Moisture in HV connector
  • Medium likelihood: HV cable insulation aged
  • Low likelihood: Pack cell imbalance approaching service threshold

Possible symptoms

  • EV/hybrid system warning light on
  • Reduced power output or limp mode
  • Charging may fail or be slowed
  • Reduced electric range

Diagnostic notes

  • The malfunction indicator lamp may illuminate
  • Reduced-power or limp mode may occur

Sources

Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.

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