Faulty or drifting boost pressure sensor 'A'; Faulty barometric pressure sensor (stand-alone or integrated in the control unit or another sensor); Damaged wiring, poor connector contact or corrosion in the sensor circuit (signal, reference or earth); Blocked, split, disconnected or oil-soaked boost sensor pipe or hose, where fitted; Boost leaks or restriction in the intake or charge air system affecting the sensor reading; Fault inside the engine control unit or an outdated calibration, where the manufacturer lists it as a known cause.

P00CF

Barometric 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
0: AreaFuel and air metering, auxiliary emission controls
CF: FaultThe specific fault in that area

What it means

P00CF is a generic code meaning the control unit has found that the barometric pressure reading and the turbocharger or supercharger boost sensor 'A' reading do not agree when they should. With the engine off or at very low load, the boost sensor should read close to ambient pressure, so a significant difference suggests one of the two signals is wrong. The exact test conditions and thresholds vary by manufacturer and engine.

Symptoms

Engine warning light on
Reduced power or limp mode
Poor or inconsistent boost response
Rough running or hesitation under load
Black or excess smoke from the exhaust on some engines
Increased fuel consumption

Possible causes

Faulty or drifting boost pressure sensor 'A'likely
Faulty barometric pressure sensor (stand-alone or integrated in the control unit or another sensor)likely
Damaged wiring, poor connector contact or corrosion in the sensor circuit (signal, reference or earth)possible
Blocked, split, disconnected or oil-soaked boost sensor pipe or hose, where fittedpossible
Boost leaks or restriction in the intake or charge air system affecting the sensor readingpossible
Fault inside the engine control unit or an outdated calibration, where the manufacturer lists it as a known causerare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine load, speed and whether other sensor codes are present
With the ignition on and engine off, compare live data for barometric pressure and boost sensor 'A'; both should be close to ambient pressure and to each other
Visually inspect the sensor connectors, wiring and the intake and charge air pipework for damage, oil, corrosion, splits or loose clamps
Check any vacuum or pressure hose to the sensor for blockage, cracks or oil contamination
Check the sensor supply voltage, earth and signal voltage against the manufacturer's specification for the model
Compare the readings with a known good gauge or a reference altitude value to decide which sensor is wrong
Pressure-test the charge air system for leaks and check for restrictions such as a blocked air filter
Check for manufacturer service bulletins or calibration updates relevant to this engine

How to fix

Replace the sensor that proves faulty (boost sensor 'A' or barometric sensor), following the manufacturer's procedure
Repair or replace damaged wiring and clean or replace corroded connectors
Replace blocked, split or oil-soaked sensor hoses and secure all connections
Repair charge air leaks and replace a blocked air filter or restricted intake component
Update the control unit calibration or repair the unit only if confirmed as the cause by diagnostics or a manufacturer bulletin

Can I keep driving?

Medium severity

The car can usually be driven short distances with care, but the control unit may limit power and boost accuracy could affect fuelling. Get it checked soon, and stop driving if the car is running badly or goes into limp mode repeatedly.

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