P225E

Turbocharger/Supercharger Boost Control B Performance

P225E is a generic OBD-II powertrain diagnostic trouble code: Turbocharger/Supercharger Boost Control B 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.

Code
P225E
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on, possible limp mode)
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What P225E means

P225E is the circuit B counterpart to P225C and is set when the PCM detects a performance deviation in the second boost control circuit or second-stage turbine on a twin-turbo or two-stage boosted engine. The actual delivered boost does not match the commanded setpoint within the calibrated tolerance window for boost control bank/circuit B.

On sequential twin-turbo systems the B circuit typically governs the second (larger) turbocharger that comes online at higher engine speeds. A fault here often shows up as a flat power curve at high RPM while low-end performance remains normal. On two-stage supercharged systems, circuit B may control the bypass valve that switches between low-stage and high-stage compressors.

Diagnosis should start with a careful review of live boost data for both circuits to isolate which stage is underperforming. Common culprits include actuator wear, vacuum leaks specific to the B circuit plumbing, and solenoid valve failures. Verify the integrity of the secondary turbo oil and coolant feed lines as turbine damage can also cause performance faults.

Common causes

Most-frequently reported root causes when P225E is logged.

  • 1
    Secondary turbocharger wastegate or bypass actuator mechanically failed or out of range.
  • 2
    Boost control solenoid for circuit B stuck, failed, or electrically intermittent.
  • 3
    Vacuum or pneumatic supply line to the B-circuit actuator leaking or disconnected.
  • 4
    Secondary turbocharger worn compressor wheel or damaged turbine blades.
  • 5
    Boost pressure sensor B inaccurate or pressure port blocked.
  • 6
    Intercooler or charge-air plumbing leak specific to the secondary boost path.
  • 7
    PCM calibration mismatch after engine or turbo replacement.

Symptoms drivers notice

Power loss predominantly at higher engine speeds or under sustained load.
MIL illuminated; possible accompanying P225C if both circuits are affected.
Engine may activate boost-limited limp mode.
Unusual turbo sounds during high-RPM acceleration.
Potentially normal low-end performance with a pronounced flat spot at high RPM.

How to diagnose P225E

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all DTCs and freeze-frame data to understand operating conditions when the fault was set.
  2. 2
    Monitor live boost pressure data for both A and B circuits to determine which stage is underperforming.
  3. 3
    Inspect vacuum/pneumatic lines and electrical connectors specific to the B-circuit solenoid and actuator.
  4. 4
    Command the B-circuit solenoid on and off via bi-directional scan tool control and verify mechanical response.
  5. 5
    Check secondary turbocharger for shaft play, compressor wheel damage, and oil supply condition.
  6. 6
    Confirm boost sensor B reads correctly using a calibrated pressure reference.
  7. 7
    Clear codes, road test under the conditions that triggered the fault, and verify resolution.

Related powertrain codes

Frequently asked questions

What distinguishes P225E from P225C?

P225C relates to the A (primary) boost control circuit, while P225E relates to the B (secondary) circuit. On a single-turbo engine only P225C is applicable; P225E appears on twin-turbo or two-stage boosted engines.

Will P225E cause the car to enter limp mode?

It depends on calibration. Many vehicles limit boost to a safe default when a boost control performance fault is confirmed, resulting in reduced power.

Can a clogged intercooler cause P225E?

A severely restricted intercooler can reduce the effective boost reaching the manifold, which the ECM may interpret as a boost performance fault.

Is it safe to clear P225E without repairing the root cause?

Clearing the code without repair will likely result in an immediate re-set under similar driving conditions and does not resolve the underlying fault.

Disabling P225E in software

RaceTune can permanently disable P225E — 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.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

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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