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 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 (LS3) [1][2]Electrical DiagramsEngine Controls Schematics (LS7) [1][2]Electrical DiagramsEngine Controls Schematics (LS9) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views 5 Bow Lowered Switch (CM7)
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
GE 23738-A - Vacuum Pump
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
1. Verify that DTC P0641 is not set.
• If the DTC is set, refer to DTC P0641 or P0651 (ECM With Supercharger) DTC P0641 or P0651 (ECM Without Supercharger) Powertrain Management (ECM Without Supercharger).
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 B17 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 ohms 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 K20 engine control module.
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 K20 engine control module.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
4. Verify the scan tool BARO sensor parameter is less than 5 kPa (0.7 psi).
• If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
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 (17.4 psi).
• If less than the specified range, test the signal circuit for an open/high resistance or a short to ground.
6. If all circuits test normal, test or replace the B17 BARO sensor.
Component Testing
Note: You must perform the Circuit/System Testing before proceeding with the Component Test.
1. Ignition OFF, remove the B17 BARO sensor.
2. Install a 3 A fused jumper between the harness connector 5 V reference circuit terminal 1 and terminal 1 of the sensor. Install a jumper wire between the low reference terminal 2 of the sensor and ground.
3. Ignition ON, test for 5.2-0 V without any spikes or dropouts between the signal terminal 3 and the low reference terminal 2 while slowly applying vacuum to the sensor with the GE 23738-A.
• If the voltage is not within the specified range or has any spikes or dropouts, replace the B17 BARO sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Barometric Pressure Sensor Replacement Service and Repair
* Control Module References Control Module References for ECM replacement, programming, and setup