Code Definition

P004C — Turbo/Super Charger Boost Control Solenoid 2 Circuit Low

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P004C

P004C is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P004C is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P004C is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

Boost control solenoid 2 is a pulse width modulated valve, driven by the Engine Control Module (ECM), that meters vacuum or pressure to the wastegate actuator or the variable geometry vane actuator so the ECM can hold manifold boost at its commanded target. The solenoid receives battery voltage through a fuse or the main relay and is switched on its ground side by the ECM, which monitors the voltage on that control circuit to confirm the driver is behaving as expected. DTC P004C is set when the ECM sees the solenoid 2 control circuit voltage pulled low, that is at or near ground potential, whe...

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