P2228
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 barometric pressure (BARO) sensor has a 5 V reference circuit, a low reference circuit, and a signal circuit. 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 barometric pressure changes.
Conditions for Running the DTC
* The ignition is ON.
* The DTCs run continuously when the above condition is met.
Conditions for Setting the DTC
P2228
The ECM detects that the BARO sensor signal is less than 51 kPa (7.4 psi) for 1 s.
P2229
The ECM detects that the BARO sensor signal is greater than 115 kPa (16.7 psi) for 1 s.
Action Taken When the DTC Sets
DTCs P2228 and P2229 are Type B DTCs.
Conditions for Clearing the MIL/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
* Measuring Frequency Measuring Frequency
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
J-23738-A Mityvac
Circuit/System Verification
1. Verify that DTC P0641 is not set.
• If the DTC is set, refer to DTC P0641 or P0651 (ECM) Powertrain Management (ECM) for further diagnosis.
2. Ignition ON, observe the BARO parameter with a scan tool. The BARO parameter should be within the range specified in the Altitude Versus Barometric Pressure Altitude Versus Barometric Pressure table for the current testing altitude.
3. 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 and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. 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 an open/high resistance or a short to ground. 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 5 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 120 kPa.
• If less than the specified range, test the sensor signal circuit for an open/high resistance or a short to ground.
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 Test.
1. Ignition ON, engine OFF, remove the BARO sensor.
2. Install a 3 A fused jumper wire between the 5 V reference terminal 1 of the sensor and 5 V reference.
3. Install a jumper wire between the low reference terminal 2 of the sensor and ground.
4. Connect a DMM between the BARO signal terminal 3 of the sensor and ground.
5. Slowly apply vacuum to the sensor with the J-23738-A while monitoring the voltage on the DMM. The voltage should vary between 5.2-0 V, without any spikes or dropouts.
• If the voltage is not within the specified range or 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 Control Module References for ECM replacement, setup, and programming