P2228

P2228-BAROMETRIC PRESSURE CIRCUIT LOW





For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.

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 Boost 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 two trip fault. During this time the ECM uses an estimated barometric pressure. The ECM turns off the MIL when the diagnostic runs and passes in 4 consecutive drive cycles.

- When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.

- Set Condition:
The circuit voltage to the ECM falls below a calibrated threshold for a certain period of time.





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 30 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION - DIESEL (Diagnostic Procedure). Intermittent Condition Test

2. (F855) 5-VOLT SUPPLY CIRCUIT OPEN OR SHORTED 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 open or short to ground in the 5-Volt Supply circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 3

3. (K616) INLET AIR PRESSURE SIGNAL CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.
2. Disconnect the Inlet Air Temperature/Pressure harness connector.
3. Measure the resistance between ground and the 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 short to ground in the (K616) Inlet Air Pressure Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 4

4. (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 POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 5

5. (K616) INLET AIR PRESSURE SIGNAL CIRCUIT OPEN




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

Is the resistance below 10.0 ohms?

Yes

- Go To 6

No

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

6. INLET TEMPERATURE/PRESSURE SENSOR
1. Reconnect the ECM 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 POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

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