DTC P2279: Intake Air System Leak
General Description
The positive crankcase ventilation (PCV) system reduces hydrocarbon (HC) emissions. The PCV system recirculates unburned air/fuel mixture (blow-by vapor) into the intake manifold so that it is drawn into the engine and burned, thus reducing HC. The amount of intake airflow from the PCV is estimated from a deviation between the amount of intake airflow of the intake manifold calculated from the manifold absolute pressure (MAP) sensor and the amount of airflow passing through the throttle body calculated with the mass airflow (MAF) sensor. When the PCV piping disengagement, etc. exists, the amount of intake airflow from the PCV increases and so do the deviation. Therefore, the estimated amount of airflow of this PCV is compared with the judgment value (upper limit value), and if this upper limit value is exceeded, the powertrain control module (PCM) detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type, OBD Status
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | 5.5 seconds or more |
| DTC Type | Two drive cycles, MIL on |
| OBD Status | PASSED/FAILED/EXECUTING/OUT OF (TEST) CONDITION |
Enable Conditions
| Condition | Minimum | Maximum | |
|---|---|---|---|
| Elapsed time after starting the engine* 2 | 15 seconds | - | |
| Elapsed time after EV drive | 5 seconds | - | |
| Engine coolant temperature [ECT SENSOR 1] |
122 °F (50 °C) | - | |
| Intake air temperature [IAT SENSOR (1)] |
19 °F (-7 °C) | - | |
| MAP value [MAP SENSOR] |
1, 000 rpm | - | -106 kPa (-31.4 inHg, -800 mmHg) |
| 2, 000 rpm | - | -26 kPa (-7.8 inHg, -200 mmHg) | |
| 12 volt battery voltage [BATTERY] |
10.5 V | - | |
| Fuel trim | 0.69 | 1.47 | |
| Fuel feedback | Closed loop | ||
| Monitoring priority* 1 | P0400, P0401, P0402, P0403, P0404, P0405, P0406, P049D, P2413 | ||
| Monitoring priority* 2 | P0400, P0401, P0404, P0406, P2413 | ||
*1: '14-15
*2: '17
[ ]: HDS Parameter
Malfunction Threshold '14-15
- Flow quantity of PCV is 200 L/min (212 US qt/min, 176 lmp qt/min) or more.
Malfunction Threshold '17
- Flow quantity of PCV is 80 L/min (85 US qt/min, 71 lmp qt/min) - 200 L/min (211 US qt/min, 175 lmp qt/min) or more*.
*: Depending on engine speed and load
Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- Vacuum hose fall
- Throttle body air leak
- Intake manifold air leak
- Evaporative emission (EVAP) canister purge valve failure
- Valve timing incorrect
Confirmation Procedure
Operating Condition
- 1.
Enter the maintenance mode, then start the engine. Hold the engine speed [ENGINE SPEED] at 3, 000 rpm without load (in P or N) until the radiator fan comes on.
- 2.
Let the engine idle for at least 5.5 seconds.
With the HDS
None.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.