Evaporative Emissions System: Testing and Inspection

ON-VEHICLE INSPECTION




1. VISUALLY CHECK HOSES, CONNECTORS AND GASKETS
a. Check that there are no cracks, leaks or damage.

NOTE:
- Detachment or other problems with the engine oil dipstick, filler cap, ventilation hose and other components may cause the engine to run improperly.
- Air suction caused by disconnections, looseness or cracks in the parts of the air induction system between the throttle body and cylinder head will cause engine failure or engine malfunctions.

If the result is not as specified, replace parts as necessary.

2. CHECK HOSES AND CONNECTORS
a. Visually check for loose connections, sharp bends or damage.




3. INSPECT EVAP SYSTEM LINE
a. Warm up the engine and stop the engine. Warm up the engine to normal operating temperature.
b. Install a vacuum gauge (EVAP control system test equipment vacuum gauge) into the EVAP service port on the purge line.




c. When using an intelligent tester:
Operation of purge VSV using intelligent tester.
1. Connect the intelligent tester to the DLC3.
2. Start the engine.
3. Turn the intelligent tester ON.
4. Select the following menu items: DIAGNOSIS /ENHANCED OBD II / ACTIVE TEST / EVAP VSV (ALONE).




d. When not using an intelligent tester:
Operation of purge VSV not using intelligent tester.
1. Disconnect the purge VSV connector.
2. Connect the positive (+) and negative (-) leads of the battery to the purge VSV terminals.
3. Start the engine.




e. Check the vacuum when the engine idles.

Vacuum: Maintains at 0.368 to 19.713 in.Hg (5 to 268 in.Aq) for over 5 seconds.

HINT: If the vacuum does not change, the hose connecting the purge VSV to the service port is loose or blocked, or the purge VSV is malfunctioning.

f. When using an intelligent tester:
Conclude operation of purge VSV using intelligent tester.
1. Stop the engine.
2. Disconnect the intelligent tester from the DLC3.

g. When not using an intelligent tester:
1. Stop the engine.
2. Disconnect the positive (+) and negative (-) leads of the battery from the purge VSV terminals.
3. Connect the purge VSV connector.

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. Prepare a rubber hose that has an inside diameter of 15 to 18.5 mm (0.590 to 0.728 in.).
2. Disconnect the atmospheric side hose of the pump module.
3. Connect the prepared rubber hose to the pump module, and pinch the rubber hose with the clip to prevent air from entering into the canister passage.




4. Apply pressure (13.5 to 15.5 in.Aq) from the EVAP service port.

Pressure: The gauge should still read over 7.7 to 8.8in.Aq for 3 minutes after the pressure is applied.

HINT: If you cannot apply pressure, the hose connecting the purge VSV, charcoal canister and fuel tank has slipped off or the purge VSV is open.




5. Check if the pressure decreases when the fuel tank cap is removed while applying pressure.

HINT: If the pressure does not decrease when the filler cap is removed, 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.




4. INSPECT FUEL CUT OFF VALVE AND FILL CHECK VALVE
a. Disconnect the vent line hose from the fuel tank.
b. Connect the pressure gauge to the fuel tank.
c. Fill the fuel tank with fuel.
d. Apply pressure of 4 kPa (41 kgf/sq.cm, 0.58 psi) to the vent port of the fuel tank.

HINT: It is necessary to check the amount of fuel tank. When the fuel tank is full, the float valve of the fill check valve is closed and no air can pass through.

e. Remove the fuel tank cap, and check that pressure drops.

If the pressure does not drop, replace the fuel tank assembly.

f. Reconnect the vent line hose to the fuel tank.




5. CHECK AIR INLET LINE
a. Disconnect the air inlet line hose from the charcoal canister.
b. Check that air can flow freely into the air inlet line. If air cannot flow freely into the air inlet line, repair or replace it.
c. Reconnect the air inlet line hose to the charcoal canister.




6. INSPECT LEAK DETECTION PUMP (PRESSURE SENSOR)




a. Measure the power source voltage of the ECM connectors.

If the voltage is not as specified, check the ECM, leak detection pump and wire harness.

b. Measure the power output of the ECM connectors.




1. Remove the fuel tank cap.

If the voltage is not as specified, check the ECM, leak detection pump and wire harness.

2. Install the fuel tank cap.

7. CHECK FUEL TANK ASSEMBLY
a. Visually check for deformation, cracks or fuel leakage.