EVAP Control System Diagnosis
- Start engine (cold). Disconnect purge hose from EVAP canister. Place finger over end of disconnected hose and check for vacuum. Vacuum should not be felt with engine below normal operating temperature. If vacuum exists, check vacuum hose routing for proper installation. If vacuum does not exist, go to next step.
- Reconnect purge hose to EVAP canister. Warm engine to normal operating temperature. Disconnect purge hose from EVAP canister. Place finger over end of disconnected hose and check for vacuum. Vacuum should be felt with engine running at normal operating temperature.
NOTE:
When purge hose is disconnected from EVAP canister with engine running at normal operating temperature, some air may be drawn into purge line. PCM may detect a change in purge gas concentration and stop purging. If this occurs, vacuum may not be felt. This is normal. To avoid possible replacement of good components, continue testing EVAP system components.