P240F
Turbocharger/Supercharger Boost Control B Circuit Range/PerformanceP240F is a generic OBD-II powertrain diagnostic trouble code: Turbocharger/Supercharger Boost Control B Circuit Range/Performance. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P240F means
DTC P240F is stored when the PCM detects that the boost control actuator or solenoid for turbocharger/supercharger circuit B is producing a signal or response within its expected electrical range but the boost pressure outcome does not match the commanded target. This is a performance or rationality fault rather than a wiring open or short. Circuit B refers to the second boost control device in systems with staged or twin-turbo arrangements.
Common causes include a mechanically stuck or carbon-fouled variable geometry or wastegate actuator, a partially blocked boost control solenoid, slow or erratic actuator response caused by worn mechanical components, or vacuum leaks in the pneumatic control circuit on systems using vacuum-operated actuators. The PCM uses boost pressure feedback from the MAP sensor to evaluate whether the actuator commanded position is producing the expected pressure response.
Extended operation with P240F active can result in overboosting or underboosting depending on the direction of the actuator fault, either risking engine damage from excessive pressure or degrading performance and efficiency from insufficient boost.
Common causes
Most-frequently reported root causes when P240F is logged.
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1
Carbon fouling or mechanical binding of the turbocharger B variable geometry vanes or wastegate.
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2
Partially blocked or sticky boost control solenoid B.
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3
Vacuum line leak or damage in the pneumatic circuit for actuator B.
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4
Worn or failed turbocharger B actuator diaphragm.
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5
Intake system boost leak downstream of the turbocharger B outlet reducing measured pressure.
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6
Sluggish turbocharger B response due to oil coking on the turbine shaft.
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7
MAP sensor fault providing inaccurate feedback used to evaluate boost control performance.
Symptoms drivers notice
How to diagnose P240F
A typical diagnostic flow when this code is present.
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1
Retrieve all DTCs and note any boost pressure, MAP, or turbocharger-related codes present alongside P240F.
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2
Monitor boost pressure PID and compare commanded versus actual boost pressure across the RPM range with a scan tool.
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3
Inspect the vacuum lines to the boost control actuator B for cracks, disconnections, or collapsed sections.
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4
Test the boost control solenoid B for proper operation using a scan tool actuator command or by applying regulated vacuum directly.
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5
Inspect the turbocharger B actuator rod, linkage, and vanes or wastegate for binding or carbon buildup.
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6
Check for intake system boost leaks using a pressure test or smoke machine.
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7
Repair or replace defective components and verify boost control response returns to within specification.
Vehicles where we've handled P240F
Platforms in our catalogue with confirmed P240F coverage.
Related powertrain codes
- P2400 — Evaporative Emission System Leak Detection Pump Control Circuit/Open
- P2401 — Evaporative Emission System Leak Detection Pump Control Circuit Low
- P2402 — Evaporative Emission System Leak Detection Pump Control Circuit High
- P2404 — EVAP Leak Detection Pump Sense Circuit: Implausible Signal
- P2405 — Evaporative Emission System Leak Detection Pump Sense Circuit Low
- P2407 — Evaporative Emission System Leak Detection Pump Sense Circuit Intermittent/Erratic
Frequently asked questions
What does the B designation mean in P240F?
B identifies the second boost control circuit or actuator in systems with more than one turbocharged stage, such as sequential or parallel twin-turbo setups.
Can P240F cause engine damage if ignored?
Yes. If the actuator is stuck in a position that allows overboosting, continued operation risks mechanical engine damage. If underboosting, performance is degraded but damage risk is lower.
Will cleaning the variable geometry vanes fix P240F?
If the root cause is carbon fouling causing slow or restricted vane movement, cleaning the vanes can resolve the performance discrepancy and clear the fault. It should be combined with a turbo inspection.
How do I confirm the solenoid is functioning correctly?
Apply a known vacuum signal directly to the actuator and observe movement, bypassing the solenoid. If the actuator moves correctly, the solenoid is the suspect component. Use a scan tool bidirectional test if available to cycle the solenoid.
Disabling P240F in software
RaceTune can permanently disable P240F — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
ECUs with a P240F disable in our catalogue
Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.
- Bosch EDC17C50 verified 1 software version
- Bosch EDC17CP09 verified 1 software version
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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