Evaporative Emissions System: Testing and Inspection

INSPECT EVAP SYSTEM LINE
a. Warm up the engine and stop the engine.

Allow the engine to warm up to normal operating temperature.

b. Install a vacuum gauge (EVAP control system test equipment vacuum gauge) to the EVAP service port on the purge line.






c. When using hand-held tester:

Forced driving of the VSV for the EVAP.
1. Connect a hand-held tester to the DLC3.
2. Start the engine.
3. Push the hand-held tester main switch ON.
4. Use the ACTIVE TEST mode on the hand-held tester to operate the VSV for the EVAP.







d. When not using hand-held tester:

Forced driving of the VSV for the EVAP.
1. Disconnect the VSV connector for the EVAP.
2. Connect the positive (+) and negative (-) leads from the battery to the VSV terminals for the EVAP.
3. Start the engine.







e. Check the vacuum at idle.

Vacuum: Maintain at 0.368 - 3.678 in.Hg (5 - 50 in.Aq) for over 5 seconds

HINT: If the vacuum does not change, it can be concluded that the hose connecting the VSV to the service port has come loose or is blocked, or the VSV is malfunctioning.

f. When using hand-held tester:

Forced driving of the VSV for the EVAP.
1. Stop the engine.
2. Disconnect the hand-held tester from the DLC3.

g. When not using hand-held tester:

Forced driving of the VSV for the EVAP.
1. Stop the engine.
2. Disconnect the positive (+) and negative (-) leads from the battery, and from the VSV terminals for the EVAP.
3. Connect the VSV connector for the EVAP.

h. Disconnect the vacuum gauge from the EVAP service port on the purge line.

i. Connect a pressure gauge to the EVAP service port on the purge line.







j. Check the pressure.
1. Close off the air drain hose at the marked position of the canister with a hose clipper or similar instrument.

HINT: Insert the hose clipper through the clearance of the front engine under cover and pinch the white marked portion of the air drain hose.







2. Increase the pressure (13.5 - 15.5 in.Aq) from the EVAP service port.

Pressure: 2 minutes after the pressure is increased, the gauge should be over 7.7 - 8.8 in.Aq.

HINT: If more pressure can not be applied, you can concluded that the hose connecting the VSV - canister - fuel tank has slipped off or the VSV is open.







3. Check if the pressure decreases when the fuel tank cap is removed while increasing pressure.

HINT: If the pressure does not decrease when the filler cap is removed, then it can be concluded that the hose connecting the service port to the fuel tank is blocked, etc.

k. Disconnect the pressure gauge from the EVAP service port on the purge line.