P0069
Manifold Absolute Pressure - Barometric Pressure 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
- 69
- FaultThe specific fault in that area
What it means
P0069 means the engine control unit has compared the manifold absolute pressure (MAP) sensor reading with the barometric pressure reading and found they do not agree when they should. This is usually checked with the engine off or at very low load, when manifold pressure should be close to atmospheric. The fault points to a sensor, wiring, air leak or intake restriction problem rather than one specific part.
Symptoms
- Engine warning light on
- Poor or hesitant acceleration
- Rough idle or unstable idle speed
- Hard starting or extended cranking
- Poor fuel economy
- Occasional limp-home or reduced power mode
Possible causes
- Faulty or drifting MAP sensor giving an inaccurate readinglikely
- Wiring or connector fault in the MAP sensor circuit (poor reference voltage, ground or signal, corrosion, chafing)likely
- Vacuum leak or split intake hose, loose connection or leaking intake manifold gasket affecting manifold pressurepossible
- Blocked or restricted air filter or intake duct, or a blocked sensor port or vacuum line to the MAP sensorpossible
- Faulty barometric pressure sensor, where fitted separately or built into the control unit or airflow sensor (depends on model)possible
- Boost leak or turbocharger control fault on turbocharged engines, where the model uses MAP for boost monitoringrare
- Internal control unit fault or outdated software, only after all other causes are ruled outrare
How to diagnose
- Read all stored and pending codes and the freeze frame data, noting engine load, speed and the MAP and barometric values when the fault set
- Check for other related codes (airflow, throttle, boost, MAP circuit) and deal with those first as they may point to the root cause
- With the ignition on and engine off, compare the live MAP reading with the barometric reading and local atmospheric pressure; they should be close
- Inspect the MAP sensor connector, wiring and seal for damage, corrosion, water ingress and chafing
- Check the sensor's vacuum or pressure hose and port, where fitted, for blockage, splits and loose connections
- Inspect the air filter, intake ducting, manifold gasket and vacuum hoses for restrictions and leaks, and smoke test the intake if needed
- Measure the sensor reference voltage, ground and signal at the connector against the manufacturer's specification for that model
- Check the live MAP value at idle and under load for sensible response, and for turbocharged engines check boost control and leaks
How to fix
- Replace the MAP sensor if its readings are out of specification or do not respond correctly
- Repair or replace damaged wiring, terminals or connectors in the sensor circuit
- Repair intake leaks by replacing split hoses, clips, seals or the manifold gasket
- Replace a blocked air filter and clear any obstruction in the intake duct or sensor port or hose
- Replace the barometric pressure sensor or the part it is built into, if confirmed faulty and where the model allows
- Apply a manufacturer software update to the control unit only if an outdated calibration is a known cause for that model
Can I keep driving?
The car can usually be driven for a short time, but the engine may run poorly and use more fuel. Get it checked soon, and stop driving if power is severely reduced or the engine runs very roughly.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.