P2228

P2228-BAROMETRIC PRESSURE CIRCUIT LOW





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The barometric pressure is measured by the Inlet Air Temperature/Pressure Sensor, which is located on the Air Cleaner Assembly. There is a key on check and a rationality check. At key on, the readings for the Intake Manifold Pressure Sensor, Exhaust Gas Pressure Sensor, and Inlet Air Pressure Sensor are compared. This fault code occurs if the inlet air pressure reading is different from the other two. During normal engine operation the rationality check verifies the inlet air pressure is reading an unreasonable value for a calibrated period of time then an error is recorded. The key-on portion of the rationality will light the MIL immediately after the diagnostic runs and fails. The rationality portion is a one trip fault. During this time the Powertrain Control Module (PCM) uses an estimated barometric pressure. The PCM turns off the MIL when the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
Any time the PCM is powered up.

- Set Condition:
The circuit voltage to the PCM falls below 0.23 Volts for one second.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. CHECK THE (F857) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN OR SHORT TO GROUND
1. The (F855) 5-Volt Supply circuit also supplies the MAP Sensor, Fuel Pressure Sensor, Exhaust Pressure Sensor, and Crankcase Pressure Sensor.

Are DTCs present for the MAP Sensor, Fuel Pressure Sensor, Exhaust Pressure Sensor, and Crankcase Pressure Sensor in addition to this DTC?

Yes

- Repair the (F857) 5-Volt Supply circuit for an open or short to ground.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L.Powertrain Verification Test

No

- Go To 3

3. CHECK THE (K616) INLET AIR PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Disconnect the Inlet Air Temperature/Pressure harness connector.
3. Measure the resistance between ground and the (K616) Inlet Air Pressure Signal circuit in the Inlet Air Temperature/Pressure Sensor harness connector.

Is the resistance below 10k Ohms?

Yes

- Repair the (K616) Inlet Air Pressure Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. CHECK FOR THE (K616) INLET AIR PRESSURE SIGNAL CIRCUIT SHORTED TO THE (K916) SENSOR GROUND CIRCUIT




1. Measure the resistance between the (K616) Inlet Air Pressure Signal circuit and (K916) Sensor Ground circuit at the Inlet Air Temperature/Pressure Sensor harness connector.

Is the resistance below 10k Ohms?

Yes

- Repair the short between the (K616) Inlet Air Pressure Signal circuit and (K916) Sensor Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 5

5. CHECK THE (K616) INLET AIR PRESSURE SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE




1. Disconnect the PCM C1 harness connector.
2. Measure the resistance of the (K616) Inlet Air Pressure Signal circuit between the PCM C1 harness connector and the Inlet Air Temperature/Pressure harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the (K616) Inlet Air Pressure Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

6. CHECK THE INLET TEMPERATURE/PRESSURE SENSOR
1. Reconnect the PCM C1 harness connector.
2. Turn the ignition on.
3. While monitoring the scan tool, use a jumper to connect the (F855) 5-Volt Supply circuit to the (K616) Inlet Air Pressure Signal circuit at the Inlet Air Temperature/Pressure Sensor harness connector.

Does the scan tool display DTC P2229 active?

Yes

- Replace the Inlet Temperature/Pressure Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.