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 P2227: Barometric Pressure (BARO) Sensor PerformanceDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5-Volt Reference | P0107, P0452, P0522, P0532, P0641, P2228 | P0069, P2228 | P0069, P0533, P0641, P2229 | 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 |
|---|---|---|---|
Operating Conditions: Ignition ON Parameter Normal Range: Altitude Versus Barometric Pressure | |||
5-Volt Reference | 0 kPa | 0 kPa | 128 kPa |
BARO Sensor Signal | 0 kPa | 0 kPa | 128 kPa |
Low Reference | -- | 124 kPa | -- |
Circuit/System Description
The barometric pressure (BARO) sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The engine control module (ECM) supplies 5 volts to the BARO sensor on a 5-volt 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
| • | DTCs P0068, P0069, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0220, P0222, P0223, P0502, P0503, P2135, P2228, P2229 are not set. |
| • | The engine run time is more than 10 seconds. |
| • | The vehicle speed is less than 100 km/h (62 mph). |
Conditions for Setting the DTC
| • | The control module detects that 80 out of 100 BARO sensor samples that 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
Control Module References for scan tool information
Special Tools
| • | J 23738-A Mityvac |
| • | J 35555 Metal 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.
- Ignition OFF, remove the BARO sensor.
- Install a 3A fused jumper wire between the 5-volt reference terminal 1 and the corresponding terminal of the BARO sensor.
- Install a jumper wire between the low reference terminal 2 of the BARO sensor and ground.
- Install a jumper wire at terminal 3 of the BARO sensor.
- Connect a DMM between the jumper wire from terminal 3 of the BARO sensor and ground.
- 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 volts, without any spikes or dropouts.
| ⇒ | If the voltage reading is erratic, replace the BARO sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
