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
has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The ECM supplies 5 volts to the BARO sensor on a 5-volt reference circuit, and provides a ground on a low reference circuit. The BARO sensor provides a voltage signal to the ECM on
a signal circuit 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 more than 20 seconds. |
| • | The mass air flow is more than 11 g/s. |
| • | The difference between the calculated manifold absolute pressure (MAP) and BARO pressure is less than 1.0 kPa for more than 3 seconds. |
| • | DTC P2227 runs continuously once the above conditions are met for 2 seconds. |
P2228 or P2229
| • | The engine is operating. |
| • | The DTCs run continuously once the above conditions are met for 2 seconds. |
Conditions for Setting the DTC
P2227
| • | The ECM detects that the BARO pressure changed more than 5 kPa within 20 seconds. |
| • | The ECM detects that the BARO pressure changed more than 30 kPa since the last ignition cycle. |
| • | Any of the condition above exist for 4 seconds or for a cumulative of 50 seconds. |
P2228
The ECM detects that the BARO sensor voltage is less than 0.20 volt for 4 seconds or for a cumulative of 50 seconds.
P2229
The ECM detects that the BARO sensor voltage is more than 4.8 volts for 4 seconds or for a cumulative of 50 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
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
- Start the engine, observe the DTC information with a scan tool. DTCs P2227, P2228, or P2229 should not set.
- If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.
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. DTCs 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 engine control module replacement, setup, and programming
