Fault codeP2228

MODERATE

Barometric Pressure Circuit Low

What this code means

Barometric Pressure Circuit Low.

P2228 is a generic code: it means the same thing on every make. P2228 belongs to family P22xx — Fuel and air metering sensors. Its page explains how to read a code and groups all its codes by part.

Type of fault

The control unit reads a voltage on this circuit below its expected range. Usual causes: a wire shorted to ground or broken, a corroded or loose connector, or the component itself. Check the wiring and connector before replacing the part — that is where many of these faults turn out to be.

Manifold pressure sensor (MAP)

The MAP sensor measures the pressure, or vacuum, inside the intake manifold. On many engines it is the main measure of engine load; on others it supplements the airflow sensor. It is often combined with the barometric pressure reading used to correct for altitude.

What you notice

Hesitation, poor acceleration, rough idle, higher consumption, and black smoke on diesels.

How to check it

Check the sensor's vacuum hose if it has one (split, disconnected or full of oil), its connector, and the intake for leaks. Engine off, the manifold pressure and the barometric pressure should be almost the same; at idle on a petrol engine the manifold pressure should drop to roughly 30 kPa. Klaro shows both.

Watch it live in Klaro

With an OBD2 adapter plugged in, these live readings show the part at work, when your car reports them:

Intake manifold pressure
Barometric pressure
Mass air flow

What to do

Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.

Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →

How to read this code

PPowertrain
2standardised code
2Fuel and air metering sensors
28P2228