P2227

DTC P2227

DTC Descriptor

DTC P2227
- Barometric Pressure (BARO) Sensor Performance

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






Typical Scan Tool Data






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 0-128 kPa. The ECM uses the BARO sensor input for fuel delivery and other diagnostics.

Conditions for Running the DTC

* DTCs P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0220, P0502, P0503, P2135, P2228, P2229 are not set.
* The engine run time is more than 10 seconds.

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.

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.

1. Turn ON the ignition with the engine OFF and remove the BARO sensor.
2. Install a 3-amp fused jumper wire between the 5-volt reference terminal C of the sensor and 5-volt reference.
3. Install a jumper wire between the low reference terminal A of the sensor and ground.
4. Install a jumper wire at the signal terminal B of the BARO sensor.
5. Connect a DMM between the jumper wire from terminal B of the sensor and ground.
6. 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. Verification Tests

* Programming and Relearning Programming and Relearning
* Barometric Pressure Sensor Replacement