Diagnostic Instructions
DTC Descriptors
DTC P2227: Barometric Pressure (BARO) Sensor Performance
DTC P2228: Barometric Pressure (BARO) Sensor Circuit Low Voltage
DTC P2229: Barometric Pressure (BARO) Sensor Circuit High Voltage
Circuit/System Description
The barometric pressure (BARO) sensor responds to changes in altitude and atmospheric conditions. This gives the engine control module (ECM) an indication of barometric pressure. The ECM uses this information to calculate fuel delivery. The BARO sensor
is located within the controller and is not serviced as a separate unit. The BARO sensor provides a voltage signal to the ECM relative to the atmospheric pressure changes. The ECM monitors the BARO sensor signal for a voltage outside of the normal range.
Conditions for Running the DTC
P2227
| • | Before the ECM can report DTC P2227 failed, DTCs P0100, P0101, P0102, P0103, P0121, P0122, P0123, P0221, P0222, P0223, P2228, and P2229 must run and pass. |
| • | The engine is operating for greater than 1 second. |
| • | The mass air flow (MAF) sensor signal is valid. |
| • | The evaporative emission (EVAP) leak test is not enabled. |
| • | DTC P2227 runs continuously when the conditions above are met for 2 seconds. |
P2228 or P2229
| • | The engine is operating. |
| • | The DTCs run continuously when the condition above is met for 2 seconds. |
Conditions for Setting the DTC
P2227
| • | The ECM detects that the BARO pressure is less than 50 kPa or greater than 115 kPa. |
| • | The ECM detects that the BARO pressure changed greater than 10 kPa within 20 seconds. |
| • | The ECM detects that the BARO pressure changed greater than 30 kPa since the last ignition cycle, and is greater than +/-2 kPa of the value predicted by the controller. The condition exists within 5 seconds of engine start up. |
| • | Any of the conditions above exist for greater than 1 second or for a cumulative of 10 seconds. |
P2228
The ECM detects that the BARO sensor voltage is less than 0.20 volt for greater than 1 second or for a cumulative of 10 seconds.
P2229
The ECM detects that the BARO sensor voltage is greater than 4.87 volts for greater than 1 second or for a cumulative of 10 seconds.
Action Taken When the DTC Sets
DTCs P2227, P2228 and P2229 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P2227, P2228 and P2229 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Start the engine. Observe the DTC information with a scan tool. DTC P2227, P2228, or P2229 should not set.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Inspect the atmospheric vent on the ECM case for one of the following conditions:
| • | Moisture in the vent inlet |
| • | Debris in the vent inlet |
| ⇒ | If a condition exists, attempt to clean or dry the atmospheric inlet. |
- Start the engine. Observe the DTC information with a scan tool. DTC P2227, P2228, or P2229 should not set.
| ⇒ | If DTC P2227, P2228, or P2229 sets, replace the ECM. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming
