Evaporative Emissions System: Testing and Inspection
INSPECTION1. INSPECT LINES AND CONNECTIONS
Visually check for loose connections, sharp bends or damage.
2. INSPECT FUEL TANK
Visually check for deformation, cracks or fuel leakage.
3. INSPECT FUEL TANK CAP
Visually check if the cap and/or gasket are deformed or damaged.
If necessary, repair or replace the cap.
4. INSPECT EVAP SYSTEM LINE
a. Warm up the engine to normal operating temperature and stop the engine.
b. Install a vacuum gauge (EVAP control system test equipment vacuum gauge) into the EVAP service port on the purge line.
c. When using a hand-held tester:
Operation of the VSV for EVAP.
1. Connect a hand-held tester to the Controller Area Network Vehicle Interface Module (CAN VIM). Then connect the CAN VIM to the Date Link Connector 3 (DLC3).
2. Start the engine.
3. Turn the hand-held tester ON.
4. Enter the following menus: DIAGNOSIS / ENHANCED OBDII/ ACTIVE TEST / EVAP VAV (ALONE)
d. When not using a hand-held tester:
Operation of the VSV for the EVAP.
1. Disconnect the VSV for the EVAP connector.
2. Connect leads from the positive (+) and negative (-) battery terminals to the VSV for EVAP terminals.
3. Start the engine.
e. Check the vacuum when the engine idles.
Vacuum: Maintain between 0.368 and 19.713 in.Hg (5 to 268 in.Aq) for over 5 seconds
HINT: If the vacuum does not change, the hose connecting the VSV and the service port is loose or blocked, or the VSV is malfunctioning.
f. When using a hand-held tester:
Conclude operation of the VSV for EVAP.
1. Stop the engine.
2. Disconnect the hand-held tester from the DLC3.
g. When not using a hand-held tester:
Conclude operation of the VSV for EVAP.
1. Stop the engine.
2. Disconnect the positive (+) and negative (-) leads of the battery from the VSV for EVAP terminals.
3. Connect the VSV for EVAP 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.
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, 0.99 to 1.14 in.Hg) from the EVAP service port.
Pressure: The gauge should still read over 7.7 to 8.8 in.Aq (0.57 to 0.65 in.Hg) for 2 minutes after the pressure is applied.
HINT: If you cannot apply pressure, the hose connecting the VSV, charcoal canister and fuel tank has slipped off or the 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 and the fuel tank may be blocked.
k. Disconnect the pressure gauge from the EVAP service port on the purge line.
5. INSPECT FUEL CUTOFF 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 gf/sq.cm 0.58 psi) to the vent port of the fuel tank.
HINT: It is necessary to check the amount of fuel in the 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 the pressure drops.
If the pressure does not drop, replace the fuel tank assembly.
f. Reconnect the vent line hose to the fuel tank.
6. 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.
7. REMOVE CHARCOAL CANISTER ASSEMBLY
8. INSPECT CHARCOAL CANISTER ASSEMBLY
a. Visually check the charcoal canister for cracks or damage.
If cracks or damage are found, replace the charcoal canister assembly.
b. Check charcoal canister operation.
1. With the purge port closed, blow 1.67 kPa (17.0 gf/sq.cm, 0.24 psi) of air into the vent port, and check that air flows from the air inlet port.
If the result is not as specified, replace the charcoal canister assembly.
2. With the vent port closed, blow 1.10 kPa (11.2 gf/sq.cm, 0.16 psi) air to the air inlet port, and check that air flows from the purge port.
If the result is not as specified, replace the charcoal canister assembly.
c. Check for air leakage.
1. Remove the air hose between ports A and B.
2. Connect the pressure gauge to the vent port of the charcoal canister.
3. While holding port B, with the purge port and the air inlet port closed and port A open, apply pressurized air 19.6 kPa (0.2 kgf/sq.cm, 2.81 psi) of pressurized air into the vent port, then confirm that the pressure is retained for 1 minute.
If the result is not as specified, replace the charcoal canister assembly.
d. Check leak detection pump.
1. Remove the detection pump from the charcoal canister.
2. Check that air flows from port A to B and then C.
If the result is not as specified, replace the charcoal canister assembly.
3. Connect the positive (+) lead to terminal 7 and the negative (-) lead to terminal 6.
4. Check that the valve is closed.
If the result is not as specified, replace the charcoal canister assembly.
5. Install the detection pump.
9. INSPECT VSV FOR EVAP
10. REINSTALL CHARCOAL CANISTER ASSEMBLY