P005F

Code

Generic P — Powertrain

Turbocharger/Supercharger Boost Control B Supply Voltage Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 18 EN: 30 RU: 19

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Page language: EN

Causes

Short to battery voltage on the Boost Control B supply wire
Failed boost control solenoid (B) with internal short
Damaged, chafed or pinched wiring harness or connector (power feed)
Corroded or loose connector / terminal at solenoid or ECM
Poor or missing ground elsewhere causing abnormal readings
Faulty PCM/ECM internal driver or voltage sensing circuit

Symptoms

Check Engine MIL illuminated
Reduced engine performance or limp mode
Incorrect boost control (overboost or underboost depending on failure)
Hesitation, poor throttle response, or surging
Possible trouble starting if multiple circuits affected

What to check

Read freeze frame and live data with a scan tool; record related boost and voltage values
Check for other stored codes (boost sensor, turbo solenoid, battery/charging)
Visually inspect wiring and connectors for damage, corrosion, pin damage, or water ingress
Check battery voltage and alternator charging (engine running) for abnormal high voltage
Back-probe supply wire at solenoid and at ECM to compare voltages
Measure coil resistance of boost control solenoid B and compare to spec

Signal parameters

Supply (B) feed: typically battery/ignition feed — nominal ~11–14.5 V with ignition ON/engine running (manufacturer-specific)
ECM sense: monitors supply; a voltage significantly above expected battery range or above internal threshold will flag 'High'
Control signal to solenoid: typically switched/PWM ground-side or PWM supply side — duty 0–100% depending on commanded boost
Coil resistance (typical range): tens to low hundreds of ohms depending on design (compare to vehicle spec)
Ground reference: near 0 V; large offsets indicate grounding or measurement issues

Diagnostic algorithm

Retrieve full freeze frame, note operating conditions when code set; check for related codes (P0234, P0238, P0299, P0563, etc.).
Perform a visual inspection of solenoid B, harness, connectors, and any splices for damage, corrosion, rodent chew, or melted insulation.
With ignition ON (engine OFF), back-probe the supply wire at the boost control B solenoid. Verify supply voltage equals battery voltage. Note any excessive voltage or noise.
Measure solenoid B coil resistance (engine off, connector disconnected). Compare to specification. An open or shorted coil indicates a bad solenoid.
With connector connected, monitor the supply wire voltage while commanding the solenoid (using a scan tool) to exercise the circuit; look for unexpected high voltages or lack of switching.
Check continuity from the solenoid supply pin to the PCM supply pin and inspect for shorts to B+ or other circuits. Wiggle harness to reproduce fault.
Inspect and test related grounds; measure voltage drops on ground circuits while cranking/operating.
If wiring, connector, and solenoid check good, suspect PCM/ECM internal driver or sensing fault. Confirm with manufacturer-specific ECU tests or swap with known-good module if supported.
Repair or replace failed components (repair wiring, replace connector, replace solenoid, or replace ECM as last resort). Clear codes and retest under the same conditions to confirm repair.

Likely causes

Short to B+ at the solenoid supply or splice
Defective boost control solenoid B (internal shorted coil or internal electronics)
Connector corrosion or bent pins increasing resistance and causing voltage anomalies
Wiring harness damaged by heat or abrasion near the turbo/engine
PCM/ECM hardware fault (less common)

Fault status

⚠️ Status

PCM detected a voltage above the allowed threshold on the Turbocharger/Supercharger Boost Control B supply circuit. Stored when the supply circuit reports a high-voltage condition.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours