LEV II EVAP Monitor Process
SEQUENCE OPERATION
| Sequence | Operation | Description |
|---|---|---|
| 1 | Fuel vapor measurement | EVAP VSV is turned OFF (closed) and EVAP pressure is measured. If EVAP pressure is not stable, EVAP monitor is canceled to prevent inaccurate monitor. |
| 2 | Vacuum introduction | EVAP VSV is turned ON (open) and CCV is turned ON (closed). As a result, intake manifold pressure (vacuum) is introduced to EVAP system. |
| 3 | EVAP leak check | EVAP VSV is turned OFF (closed) to seal EVAP system. EVAP pressure increase is measured for 5 seconds when EVAP pressure is -20 mmHg and -17 mmHg. If increase is large, ECM concludes EVAP system has leak. |
| 4 | Restore | CCV is turned OFF (open) to finish EVAP monitor. |