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P0238 Powertrain

Turbocharger/Supercharger Boost Sensor "A" Circuit High

The boost pressure A signal voltage is above the upper diagnostic threshold — short to supply voltage or defective sensor.

Affected components

  • Boost pressure sensor
  • Boost sensor wiring

Common causes

  • High likelihood: Sensor circuit shorted to supply voltage
  • Medium likelihood: Boost pressure sensor failed
  • Low likelihood: Connector pins corroded - high contact resistance

Possible symptoms

  • Check engine light on
  • Significant power loss / limp mode
  • Possible blue or black smoke from exhaust
  • Whistling or hissing sound from intake

Diagnostic notes

  • The malfunction indicator lamp may illuminate
  • This code can affect emissions
  • Reduced-power or limp mode may occur

Related codes

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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