For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC P2228 00: Barometric Pressure Sensor Circuit Low Voltage
DTC P2229 00: Barometric Pressure Sensor Circuit High Voltage

### Circuit/System Description

The barometric pressure (BARO) sensor is integrated within the engine control module (ECM). The BARO sensor responds to changes in altitude and atmospheric conditions. The BARO sensor provides the ECM an indication of barometric pressure. 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

The ignition is ON or the engine is running.

### Conditions for Setting the DTC

#### P2228 00

• | The ECM detects that the BARO sensor voltage is less than 2.1 V.

• | The condition exists for greater than 1.5 s.

#### P2229 00

• | The ECM detects that the BARO sensor voltage is greater than 4.7 V.

• | The condition exists for greater than 1.5 s.

### Action Taken When the DTC Sets

DTCs P2228 and P2229 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P2228 and P2229 are Type B DTCs.

### Reference Information

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References

### Circuit/System Verification

1. Engine running, observe the DTC information with a scan tool. DTCs P2228 or P2229 should not set.
2. 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

1. Inspect the atmospheric vent on the K20 Engine Control Module (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.

2. Engine running, observe the DTC information with a scan tool. DTCs P2228 or P2229 should not set.

⇒ | If DTC P2228 or P2229 sets, replace the K20 Engine Control Module (ECM).

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for engine control module replacement, setup and programming