P2229 low

Barometric Pressure Sensor A Circuit High

The P2229 code means the vehicle's onboard diagnostic system has detected: Barometric Pressure Sensor A Circuit High. This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
moderate
Estimated cost
$40 - $250 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Engine running rich
  • Reduced fuel economy
  • Black smoke under load
  • Sluggish acceleration

Probable Causes (Ranked by Likelihood)

  • Short to voltage in the BARO sensor A wiring Very High
  • Failed BARO sensor A reading high High
  • Water intrusion in the sensor connector Moderate
  • Signal wire shorted to the reference voltage wire Moderate
  • ECM internal circuit fault Low

Step-by-Step Diagnostic Procedure

  1. Read BARO sensor A value -- check if pegged at maximum

  2. Inspect wiring for shorts to power or to other sensor wires

  3. Check the connector for water intrusion or damaged pins

  4. Disconnect the sensor and verify signal drops to confirm sensor fault

  5. Replace the sensor if wiring checks pass

Frequently Asked Questions

What happens when BARO sensor A reads high?

A high reading tells the ECM the vehicle is at a lower altitude than it actually is, causing it to add more fuel than needed, resulting in a rich condition.

Can a shorted signal wire cause P2229?

Yes, if the signal wire shorts to the 5V reference wire, the sensor output will read at or near maximum voltage, triggering the high circuit code.

Is P2229 related to the MAP sensor?

On some vehicles the MAP and BARO functions share a sensor. If your vehicle uses a separate BARO sensor, P2229 is specific to that sensor and not the MAP.

Sources

This page is built from documented references. Verify against your own service info before repair work.

P2229 on Diesel, EV & Equipment

The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:

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