Faulty boost sensor B (manifold pressure sensor) or MAP sensor; Damaged or corroded wiring or connectors in the sensor circuits; Leaking or restricted vacuum/boost hoses to the sensors; Carbon buildup or blockage in the sensor port or intake manifold; Failed PCM or software issue (less common); Intercooler or charge pipe leaks causing pressure discrepancies; Exhaust gas recirculation (EGR) valve sticking or leaking, affecting pressure readings

DTC codes / P02xx · Fuel and air metering (injector circuits) / P023E

P023EManifold Absolute Pressure - Turbocharger/Supercharger Boost Sensor B Correlation

P023E indicates that the powertrain control module (PCM) has detected a correlation error between the manifold absolute pressure (MAP) sensor and the turbocharger/supercharger boost sensor B. The PCM compares the two pressure signals under specific operating conditions and flags the code when they deviate beyond an acceptable threshold, suggesting a sensor, wiring, or mechanical issue.

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 during acceleration
Poor fuel economy or rough running under boost
Hesitation or stumble when the turbocharger spools up
In rare cases, a noticeable loss of boost pressure

Common causes, most likely first

Faulty boost sensor B (manifold pressure sensor) or MAP sensor
Damaged or corroded wiring or connectors in the sensor circuits
Leaking or restricted vacuum/boost hoses to the sensors
Carbon buildup or blockage in the sensor port or intake manifold
Failed PCM or software issue (less common)
Intercooler or charge pipe leaks causing pressure discrepancies
Exhaust gas recirculation (EGR) valve sticking or leaking, affecting pressure readings

How to diagnose and fix it

Perform a visual inspection of all vacuum and boost hoses for cracks, leaks, or disconnections
Use a scan tool to check live data from both MAP and boost sensor B to compare readings
Test the sensors with a multimeter for proper reference voltage and signal return
Check wiring continuity and resistance between sensors and PCM, looking for shorts or opens
Clean the sensor ports and intake manifold passages to remove carbon deposits
Replace the faulty sensor (MAP or boost sensor B) if testing confirms failure
If all else fails, reprogram or replace the PCM as a last resort

Common misdiagnosis traps for P023E

A dirty or clogged MAP sensor port can cause skewed readings that mimic a failed sensor, so cleaning before replacement often resolves the issue.
Boost leaks from cracked intercooler pipes or loose clamps can create pressure discrepancies that set this code without any sensor fault.
The code may be triggered by a failing EGR valve that alters intake pressure, leading technicians to overlook the EGR system entirely.
On some vehicles, a weak battery or charging system issue can cause voltage drops that affect sensor signals and set false correlation codes.
After replacing a sensor, the PCM may require a relearn procedure or drive cycle to clear the code and verify the repair.

Can I keep driving with P023E?

You can usually drive the vehicle with this code, but avoid heavy acceleration or towing until it is diagnosed, as the engine may enter limp mode and reduce power unexpectedly.

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.