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P28C2 Powertrain

Ion Sense Module Supply Voltage High

Supply voltage on the ion sense module is above the expected window. Charging system overvoltage or upstream regulator fault.

Affected components

  • Ion sense module
  • Wiring harness

Common causes

  • High likelihood: Alternator regulator drift - overvoltage
  • Medium likelihood: Supply wire shorted to B+

Diagnostic notes

  • The malfunction indicator lamp may illuminate
  • This code can affect emissions

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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