Leak or split in the charge air pipework, intercooler, hoses or clamps between the boost sensor and the intake manifold; Faulty or contaminated MAP sensor or boost pressure sensor giving a drifting or inaccurate reading; Damaged wiring, poor connector contact, corrosion or high resistance in the sensor supply, earth or signal circuits; Blocked, cracked or disconnected sensor vacuum or pressure port or pipe, where fitted; Turbocharger or boost control fault (wastegate, actuator or variable geometry mechanism) causing a real pressure difference; Restricted intake or exhaust, such as a blocked air filter or clogged particulate filter, altering pressure readings; Engine control unit fault or outdated calibration, where the manufacturer has identified one for the model.

P023D

Manifold Absolute Pressure - Turbocharger/Supercharger Boost Sensor A Correlation.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
3D: FaultThe specific fault in that area

What it means

P023D is a generic code meaning the signal from the manifold absolute pressure (MAP) sensor and the turbocharger or supercharger boost sensor 'A' do not agree with each other when compared. The engine control unit expects the two pressure readings to match within a set tolerance under given conditions, such as key on engine off or during boost. It sets the code when the difference is too large or stays out of range for too long.

Symptoms

Engine warning light on
Reduced power or car going into limp mode
Poor or inconsistent boost response
Hesitation or flat spots when accelerating
Rough running or uneven idle
Possible black smoke or poor fuel economy

Possible causes

Leak or split in the charge air pipework, intercooler, hoses or clamps between the boost sensor and the intake manifoldlikely
Faulty or contaminated MAP sensor or boost pressure sensor giving a drifting or inaccurate readinglikely
Damaged wiring, poor connector contact, corrosion or high resistance in the sensor supply, earth or signal circuitslikely
Blocked, cracked or disconnected sensor vacuum or pressure port or pipe, where fittedpossible
Turbocharger or boost control fault (wastegate, actuator or variable geometry mechanism) causing a real pressure differencepossible
Restricted intake or exhaust, such as a blocked air filter or clogged particulate filter, altering pressure readingsrare
Engine control unit fault or outdated calibration, where the manufacturer has identified one for the modelrare

How to diagnose

Read all stored and pending codes and review freeze frame data, noting load, engine speed and boost at the time the code set
Visually inspect both sensors, their connectors and wiring for damage, oil, water ingress, corrosion or chafing
Inspect the intake and charge air system, including hoses, clamps, intercooler and connections, for splits, oil residue or looseness
With key on and engine off, compare live MAP and boost sensor readings against each other and against ambient pressure; they should be very close
Check sensor supply voltage, earth and signal wiring against the manufacturer's data, and test for continuity and voltage drop
Compare both sensor readings during a road test or under load and see which one deviates from the commanded boost
Smoke or pressure test the charge air system to find leaks, and check that the sensor ports are clear
Check the boost control components, such as the actuator and wastegate or variable geometry operation, following model-specific procedures

How to fix

Repair or replace leaking, split or loose charge air hoses, clamps or intercooler components
Replace whichever pressure sensor is proven faulty or contaminated, and clean or clear the sensor port
Repair damaged wiring, terminals or connectors in the sensor circuits
Repair or replace the boost control actuator, wastegate or turbocharger if it is not delivering the commanded pressure
Fix intake or exhaust restrictions such as a blocked air filter, then clear the code and confirm it does not return
Apply a manufacturer-issued control unit software update only if one is documented for this fault on the vehicle

Can I keep driving?

Medium severity

The car can usually be driven carefully for a short time, but power may be limited and a real boost leak or turbo fault could worsen. Get it diagnosed soon and avoid heavy loads or hard acceleration in the meantime.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.