Y. Checking the Evaporative Emission (EVAP) System

Y. Checking the evaporative emission (EVAP) system

Y1




Checking the evaporative emission (EVAP) valve
- Disconnect the ventilation hose and the canister control from the TB.
- Connect a vacuum pump to the ventilation hose (the thick hose) and pump out air.
When pumping a partial vacuum should be displayed on the meter.
The pressure quickly returns to atmospheric pressure. However there is a noticeable resistance to pumping.

If partial vacuum and resistance are OK:
^ Check vacuum hose Y2.

If partial vacuum or resistance are not obtained:
^ Check the ventilation hose to the canister for damage or leaks.

If the ventilation hose is OK:
^ Try using a new canister

Y2




Checking the vacuum hose
- Pump air out of the vacuum hose (the thin hose). The meter should display a partial vacuum.

If a partial vacuum is obtained:
^ Check the canister control Y3

If no partial vacuum is obtained:
^ Check the vacuum hose for damage or leaks.

If the vacuum hose is OK:
^ Try using a new canister.

Y3




Checking the canister control
- Release the vacuum.
- Blow into the ventilation hose (the thick hose).
The hose should be airtight.

If the ventilation hose is not airtight:
^ Check the hose for damage.

If the hose is OK:
^ Pump air out of the thin hose.
^ Blow into the ventilation hose again.
It should be possible to blow through the canister valve with only a light resistance.

If the valve is OK:
The canister and canister control are OK.
^ Return to fault tracing where it was interrupted.

If the valve is sealed.
^ Try using a new canister.