P2229
DTC P2228 or P2229
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P2228
- Barometric Pressure (BARO) Sensor Circuit Low Voltage
DTC P2229
- Barometric Pressure (BARO) Sensor Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The engine control module (ECM) supplies 5 V to the BARO sensor on a 5 V 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. Changes in BARO due to weather are relatively small, while changes due to altitude are significant. Pressure can range from 56 kPa at an altitude of 4,267 meters (14,000 feet) to 105 kPa at or below sea level. The BARO sensor has a range of 0-128 kPa.
Conditions for Running the DTC
* The engine has been running for greater than 30 s.
* DTCs P2228 and P2229 run continuously when the above condition is met.
Conditions for Setting the DTC
P2228
The ECM detects the BARO voltage is less than 2 V for greater than 1 s.
P2229
The ECM detects the BARO voltage is greater than 4.5 V for greater than 1 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
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Special Tools
* J-23738-A Mityvac
* J-35555 Metal Mityvac
Circuit/System Verification
1. Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description (Hybrid Modes of Operation).
2. Ignition ON, verify the scan tool hood position parameter displays Open.
• If the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for DTC P254F.
3. Ignition ON, observe the scan tool DTC information. Verify that DTCs P0641 or P0651 are not set.
• If a DTC is set, refer to DTC P0641 or P0651 (ECM) (P0641).
4. Ignition ON, observe the scan tool BARO parameter and compare the value to the Altitude Versus Barometric Pressure (Altitude Versus Barometric Pressure) table. The parameter should be within the range specified in the table for the current altitude.
5. 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. Ignition OFF, disconnect the harness connector at the BARO sensor.
2. Ignition OFF for 2 minutes and scan tool powered OFF, test for less than 5 ohm between the low reference circuit terminal 2 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool BARO sensor parameter is less than 2 kPa.
• If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 1. Verify the scan tool BARO sensor parameter is greater than 126 kPa.
• If less than the specified range, test the signal circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.
6. If all circuits test normal, test or replace the BARO sensor.
Component Testing
Note: You must perform the Circuit/System Testing before proceeding with the Component Testing.
1. Ignition OFF, remove the BARO sensor.
2. Install a 3 A fused jumper wire between the 5 V reference circuit terminal 1 and the corresponding terminal of the BARO sensor.
3. Install a jumper wire between the low reference circuit terminal 2 of the BARO sensor and ground.
4. Install a jumper wire at terminal B of the BARO sensor.
5. Connect a DMM between the jumper wire from terminal 3 of the BARO sensor and ground.
6. Ignition ON, with the J-23738-A or J-35555 , slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 0-5.2 V without any spikes or dropouts.
• If the voltage reading is erratic, replace the BARO sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Barometric Pressure Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming