Faulty manifold absolute pressure sensor or boost pressure sensor A; Damaged, corroded, or loose wiring or connector at either sensor; Intake air leak between the turbocharger and the intake manifold, such as a split hose or loose clamp; Clogged or restricted boost pressure sensor port or tube due to carbon buildup; Sticking or failed turbocharger wastegate or variable geometry actuator affecting boost control; Engine control module software issue or, rarely, a failed ECM

DTC codes / P02xx · Fuel and air metering (injector circuits) / P023D

P023DManifold Absolute Pressure - Turbocharger/Supercharger Boost Sensor A Correlation

P023D indicates that the engine control module has detected a disagreement between the manifold absolute pressure sensor and the turbocharger or supercharger boost sensor A during the same operating conditions. The computer compares these two pressure readings and sets the code when the correlation falls outside the expected range, which usually points to a sensor, wiring, or boost control issue rather than a mechanical failure inside the engine.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode triggered by the ECM to protect the turbocharger
Hesitation or stumble during acceleration when boost pressure is expected
Poor fuel economy or rough running if the pressure mismatch affects fuel delivery
In rare cases, a slight whistling or hissing noise from the intake system if a leak is present

Common causes, most likely first

Faulty manifold absolute pressure sensor or boost pressure sensor A
Damaged, corroded, or loose wiring or connector at either sensor
Intake air leak between the turbocharger and the intake manifold, such as a split hose or loose clamp
Clogged or restricted boost pressure sensor port or tube due to carbon buildup
Sticking or failed turbocharger wastegate or variable geometry actuator affecting boost control
Engine control module software issue or, rarely, a failed ECM

How to diagnose and fix it

Perform a visual inspection of all intake and boost hoses for cracks, loose clamps, or disconnected lines
Use a scan tool to check live data for both manifold absolute pressure and boost pressure sensors and compare readings with key on, engine off and during revving
Check the sensor connectors and wiring for corrosion, chafing, or loose pins, and repair as needed
Remove and clean the boost pressure sensor port and tube to eliminate carbon blockage
Test the manifold absolute pressure sensor and boost pressure sensor with a multimeter or replace with a known-good unit for comparison
Inspect the turbocharger wastegate or variable geometry actuator for free movement and correct operation
If all else checks out, reprogram or replace the engine control module as a last resort

What the correlation code really tells you

A P023D is often set by a simple intake leak that only appears under boost, so a smoke test of the intake system is more reliable than a visual inspection alone.
The code does not automatically mean the turbocharger is failing; many cases are resolved by cleaning the boost sensor port or replacing a $30 sensor.
On some vehicles, the manifold absolute pressure sensor and boost pressure sensor are the same part, and swapping them can quickly confirm a sensor fault.
A dirty air filter or restricted intake can cause both sensors to read low and set a correlation code, so check the air filter and intake tract before condemning sensors.
After repairs, the ECM may need several drive cycles with steady boost to self-test and clear the code, so do not assume the fix failed if the light stays on immediately.

Can I keep driving with P023D?

You can usually drive the vehicle to a repair shop, but avoid heavy acceleration or sustained high-speed driving because the ECM may limit boost and the engine could enter limp mode. If the check engine light starts flashing or you notice severe power loss, stop driving and have the vehicle towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.