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P004C Powertrain

Turbocharger/Supercharger Boost Control B Circuit Low

Boost control B circuit voltage below expected range. Same as P0047 on actuator B. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.

Affected components

  • Boost control solenoid b
  • Actuator wiring

Common causes

  • High likelihood: Wiring shorted to ground
  • Low likelihood: Connector pins corroded - high contact resistance
  • Low likelihood: Harness chafing through insulation

Possible symptoms

  • Charge status indicator shows fault
  • Charging may not start or interrupts
  • Slower-than-expected charge rate

Diagnostic notes

  • The malfunction indicator lamp may illuminate
  • This code can affect emissions
  • A drive cycle may be required after repair
  • 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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