P2227

DTC P2227

DESCRIPTION
The DTC P2227 Barometric Pressure (BARO) Sensor Performance diagnostic checks the accuracy of the BARO sensor signal. The BARO sensor and circuitry are located inside of the powertrain control module (PCM). Barometric pressure varies with weather conditions and changes in the altitude from sea level. The PCM modifies fuel and spark delivery in response to barometric pressure changes. The PCM compares the BARO sensor reading with the manifold absolute pressure (MAP) sensor reading when running the DTC P2227 diagnostic.

DTC DESCRIPTOR
This diagnostic supports the following DTC. DTC P2227 Barometric Pressure (BARO) Sensor Performance.

CONDITIONS FOR RUNNING THE DTC
- DTCs P0107, P0108, P0117, P0118, P0122, P0123, P0171, P0172, P0174, P0175, P0222, P0223, P0300-P0306, P0401, P0404, P0506, P0507, P1128, P1129, P2100, P2101, P2108, P2122, P2123, P2127, P2128, P2135, P2138, P2176, P2228, .P2229, P2282, P2413 and U0107 are not set.
- The throttle position (TP) is at least 22.3 degrees at 1,000 RPM or 34.6 degrees at 3,000 RPM.
- DTC P2227 runs once per drive cycle when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
- The difference between the BARO reading and the MAP reading is 26 kPa or more.
- The above conditions are met for 3 seconds or more.

ACTION TAKEN WHEN THE DTC SETS
- The PCM illuminates the malfunction indicator lamp (MIL) after 2 consecutive ignition cycles in which the diagnostic runs with the fault active.
- The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.
- The PCM enters the Fail Safe Function and uses default BARO values.

CONDITIONS FOR CLEARING THE MIL/DTC
- The MIL turns OFF after 3 consecutively passing trips without a fault present.
- A history DTC clears after 40 consecutive warm-up cycles without a fault.
- Perform the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
- A malfunctioning or skewed MAP sensor may cause DTC P2227 to set.
- The barometric pressure varies depending on the weather conditions and the altitude. Typical barometric pressure at sea level is 100 kPa (29-30 in Hg).
- If a DTC P2227 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC was first set.

TEST DESCRIPTION

Steps 1-10:

The numbers below refer to the step numbers in the diagnostic table.
1. The Diagnostic System Check-Computers and Control Systems prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
2. This step checks for a MAP sensor fault.
3. This step checks the accuracy of the MAP sensor. The MAP sensor should indicate atmospheric pressure when the ignition is ON and the engine is not running.
4. This step checks for a faulty BARO sensor. The BARO sensor and the MAP sensor should indicate approximately the same pressure when the ignition is ON and the engine is not running.
8. After replacing the PCM a new minimum throttle position and idle speed must also be established.