P2228

DTC P2228

Circuit Description

The barometric pressure (BARO) sensor is a transducer that varies resistance according to changes in altitude and atmospheric conditions. This gives the powertrain control module (PCM) an indication of the current barometric pressure. The PCM uses this information to calculate fuel delivery. The BARO sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The PCM supplies 5 volts to the BARO sensor on a 5-volt reference circuit, and provides a ground on the low reference circuit. The BARO sensor provides a voltage signal to the PCM on a signal circuit relative to the pressure changes. The PCM monitors the BARO sensor signal for voltage outside of the normal range. If the PCM detects a BARO sensor signal voltage that is excessively low, DTC P2228 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2228 Barometric Pressure (BARO) Sensor Circuit Low Voltage

Conditions for Running the DTC

* The ignition is ON.
OR
The engine is cranking or running.
* This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTC

* The PCM detects that the BARO is less than 50 kPa for more than 8 seconds.
OR
* The PCM detects that the BARO signal voltage is less than 0.51 volt for more than 8 seconds.

Action Taken When the DTC Sets

* The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
* The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

* The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
* A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
* A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
* Clear the MIL and the DTC with a scan tool.

Test Description

Step 1 - Step 10:

Step 11 - Step 15:

The number below refers to the step number on the diagnostic table.
2. The BARO sensor 5-volt reference circuit is shared with other sensors. If DTC P0641 is set, this indicates a shorted 5-volt reference circuit or a shorted component and should be diagnosed first.