OBD-II Code P2228 — What It Means & How to Fix It

What it means

Your car uses a barometric pressure (BARO) sensor to measure outside air pressure so it can adjust the fuel mixture for altitude.
P2228 means the BARO sensor signal is below the minimum expected voltage.
This can cause the engine to run rich, feel sluggish, or hesitate under load.

Affected Models

All vehicles 1996+
Common in General Motors vehicles
Common in Ford vehicles
Common in Dodge/Ram vehicles
Common in vehicles driven at high altitude

Common Causes

Faulty barometric pressure sensor sending low voltage
Short to ground in the sensor signal wire
Damaged or corroded wiring harness connector
Failed MAP sensor — some vehicles share BARO and MAP sensor functions
Vacuum leak near the intake that affects pressure readings

How to Fix It

Scan for all codes — MAP sensor codes often appear alongside P2228.

On many vehicles, the MAP and BARO sensors share circuits — a MAP code confirms where to focus your diagnosis.
Inspect the BARO sensor wiring harness for damage, cuts, or corrosion.

A wire shorted to ground will pull the signal voltage below the minimum threshold, triggering this code.
Check for vacuum leaks in the intake manifold area.

Vacuum leaks affect the pressure environment the sensor reads, potentially pushing readings out of range.
Test BARO sensor voltage with a multimeter — compare to expected range.

At sea level, BARO sensor output should be close to 4.5–5V; lower altitudes produce higher voltage readings.
Replace the barometric pressure sensor if it tests out of spec.

On some vehicles the BARO sensor is integrated into the MAP sensor — replacing both units together may be necessary.

When to Call a Professional

If basic wiring and connector checks don't clear the code, have a mechanic perform a full sensor circuit test.
Diagnosis involves comparing live BARO sensor voltage to known-good values at your current altitude.
Expect to pay $80–$130 for diagnosis; the sensor itself typically costs $30–$100 to replace.

Frequently Asked Questions

What does the barometric pressure sensor do?

It measures atmospheric pressure outside the car.
The ECM uses this to adjust the air/fuel mixture for altitude changes.
Higher altitude means less air, so the engine needs less fuel.

Can I drive with P2228?

Yes, but your fuel economy may suffer and the engine could run rough.
Fix it soon to avoid long-term fuel system strain.

Is the BARO sensor the same as the MAP sensor?

On some vehicles they are the same unit.
On others they are separate.
Your repair manual will clarify which setup your vehicle uses.