Open or high-resistance wire in the BARO sensor signal circuit; Short to voltage on the BARO sensor signal circuit; Faulty barometric pressure sensor; Corroded or loose electrical connector at the BARO sensor; Poor ground connection for the BARO sensor; Failed ECM (rare, but possible after other causes are ruled out)

DTC codes / P22xx · Fuel and air metering (injector circuits) / P2229

P2229Barometric Pressure Circuit High

Q: What does code P2229 mean?

Barometric Pressure Circuit High. P2229 means the engine control module (ECM) has detected a voltage signal from the barometric pressure (BARO) sensor circuit that is higher than the maximum expected value for the current conditions. The BARO sensor measures atmospheric pressure so the ECM can calculate air density and adjust fuel delivery; a high signal typically indicates an open circuit, a short to voltage, or a faulty sensor.

P2229 means the engine control module (ECM) has detected a voltage signal from the barometric pressure (BARO) sensor circuit that is higher than the maximum expected value for the current conditions. The BARO sensor measures atmospheric pressure so the ECM can calculate air density and adjust fuel delivery; a high signal typically indicates an open circuit, a short to voltage, or a faulty sensor.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light (malfunction indicator lamp) with no other noticeable symptoms
Rough idle or poor engine performance, especially at high altitudes
Reduced fuel economy or black smoke from the exhaust due to rich fuel mixture
Hesitation or stumble during acceleration
Hard starting or stalling after the engine is started
In some vehicles, a fail-safe mode that limits engine power

Common causes, most likely first

Open or high-resistance wire in the BARO sensor signal circuit
Short to voltage on the BARO sensor signal circuit
Faulty barometric pressure sensor
Corroded or loose electrical connector at the BARO sensor
Poor ground connection for the BARO sensor
Failed ECM (rare, but possible after other causes are ruled out)

How to diagnose and fix it

Use a scan tool to read the BARO sensor voltage and compare it with a known-good value or a barometer reading for your altitude.
Visually inspect the BARO sensor and its connector for damage, corrosion, or loose pins; repair or replace as needed.
Check the sensor's reference voltage and ground circuits with a digital multimeter; repair any open or shorted wires.
Backprobe the signal wire at the sensor and at the ECM to check for continuity and voltage drops; repair high-resistance wiring.
If the wiring and connections are good, replace the barometric pressure sensor.
Clear the diagnostic trouble codes and perform a road test to verify the repair; if the code returns, recheck the ECM and its programming.

What a high BARO reading really tells you

A high BARO signal often sets when the sensor circuit is open, causing the ECM to see a voltage near 5 volts instead of the normal 1–4 volt range, which can be mistaken for a sensor failure when the real problem is a broken wire.
Some vehicles use the mass air flow (MAF) sensor to infer barometric pressure, so a P2229 may appear alongside MAF-related codes even though the BARO sensor itself is not the root cause.
The BARO sensor is sometimes integrated into the ECM or the MAF sensor, making replacement more involved and requiring reprogramming or calibration after installation.
Altitude and weather changes can cause slight variations in BARO voltage, but a P2229 indicates a hard fault, not a normal fluctuation; do not dismiss it as a temporary glitch.
A faulty ground for the BARO sensor can cause a high signal voltage, so always check ground integrity before condemning the sensor or ECM.

Can I keep driving with P2229?

You can usually drive with P2229 set, but the engine may run rich and exhibit poor performance, especially at high altitudes. Avoid sustained heavy acceleration or towing until the fault is repaired, as prolonged rich operation can damage the catalytic converter and spark plugs.

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.