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 provide an overview of each diagnostic category. |
DTC Descriptor
DTC P2227: Barometric Pressure (BARO) Sensor PerformanceDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5-Volt Reference | P0069, P0651, P2228, P0530 | P0069, P2228 | P0651, P2229, P0069 | P2227 |
BARO Sensor Signal | P0069, P2228 | P0069, P2228 | P0069, P2229 | P2227 |
Low Reference | -- | P0069, P2229 | -- | P2227 |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Parameter Normal Range: Altitude Versus Barometric Pressure | |||
5-Volt Reference | 8 kPa | 8 kPa | 200 kPa |
BARO Sensor Signal | 8 kPa | 8 kPa | 200 kPa |
Low Reference | -- | 191 kPa | -- |
Circuit/System Description
The barometric pressure (BARO) sensor measures the pressure of the atmosphere. This pressure is affected by altitude and weather conditions. A diaphragm within the BARO sensor is displaced by the pressure changes that occur from varying altitudes and weather conditions. The sensor translates this action into electrical resistance. The BARO sensor wiring includes 3 circuits. The BARO sensor and all related circuits are inside the engine control module (ECM). The BARO sensor provides a signal voltage to the ECM, relative to the pressure changes on the BARO sensor signal circuit. The ECM converts the signal voltage input to a pressure value. 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 8-200 kPa. The ECM uses the BARO sensor input for fuel delivery and other diagnostics.
Conditions for Running the DTC
| • | DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0128, P0220, P0502, P0503, P2135, P2228, P2229 are not set. |
| • | The engine run time is more than 10 seconds. |
| • | Vehicle speed is greater than 256 RPM. |
Conditions for Setting the DTC
| • | The control module detects that 80 out of 100 consecutive BARO sensor samples vary more than 10 kPa between each sample. |
| • | The above condition is met for 10 seconds. |
Action Taken When the DTC Sets
DTC P2227 is a Type B DTC.
Conditions for Clearing the DTC
DTC P2227 is a Type B DTC.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Special Tools Required
J 23738-A Mityvac
Circuit/System Verification
Ignition ON, observe the scan tool MAP and BARO sensor parameters. The readings should be within 5 kPa of each other, and also the current BARO for your location. Refer to Altitude Versus Barometric Pressure .
Circuit/System Testing
Start the vehicle and monitor the BARO parameter with the scan tool for a steady value.
| ⇒ | If the BARO parameter fluctuates rapidly: |
| • | Test for an intermittent and for a poor connection at the BARO sensor. |
| • | Test for proper BARO wiring harness routing. |
| • | Test all of the BARO sensor circuits for intermittent shorts or opens. |
| • | Test for an intermittent and for a poor connection at the control module. |
| ⇒ | If the circuits test normal, replace the BARO sensor. |
Component Testing
Important: You must perform the Circuit/System Testing before proceeding with the Component Test.
- Turn ON the ignition with the engine OFF and remove the BARO sensor.
- Install a 3A fused jumper wire between the 5-volt reference terminal C of the sensor and 5-volt reference.
- Install a jumper wire between the low reference terminal A of the sensor and ground.
- Install a jumper wire at the signal terminal B of the BARO sensor.
- Connect a DMM between the jumper wire from terminal B of the sensor and ground.
- Install the J 23738-A to the BARO sensor vacuum port. Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 5.2-0 volts 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 after completing the diagnostic procedure.
