Evaporative Emissions System: Testing and Inspection
INSPECTION1. INSPECT LINES AND CONNECTORS
Visually check for loose connections, kinds or damage.
2. INSPECT FUEL TANK FILLER PIPE
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 the normal operating temperature.
b. Stop the engine.
c. Connect the vacuum gauge (EVAP control system test equipment vacuum gauge) to the EVAP service port on the purge line.
d. If you have the TOYOTA hand-held tester:
Force the VSV for EVAP to operate.
1. Connect the TOYOTA hand-held tester to the DLC3.
2. Start the engine.
3. Turn the TOYOTA hand-held tester main switch ON.
4. Select the ACTIVE TEST mode on the TOYOTA hand-held tester to operate the VSV for the EVAP.
e. If you do not have the TOYOTA hand-held tester:
Force the VSV for EVAP to operate.
1. Disconnect the VSV for EVAP connector.
2. Connect the positive (+) and negative (-) leads from the battery to the VSV for EVAP terminals.
3. Start the engine.
f. Check the vacuum at idle.
Vacuum: Minimum between 0.368 and 19.713 in.Hg (5 - 268 in.H2O) 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.
g. If you have the TOYOTA hand-held tester:
Return to normal VSV for EVAP operation.
1. Stop the engine.
2. Disconnect the TOYOTA hand-held tester from the DLC3.
h. If you do not have the TOYOTA hand-held tester:
Return to the normal VSV for EVAP operation.
1. Stop the engine.
2. Disconnect the positive (+) and negative (-) leads from the battery, and from the VSV for EVAP terminals.
3. Reconnect the VSV for EVAP connector.
i. Disconnect the vacuum gauge from the EVAP service port on the purge line.
j. Connect a pressure gauge to the EVAP service port on the purge line.
k. If you have the TOYOTA hand-held tester:
Force the VSV for canister closed valve (CCV) to operate.
1. Connect the TOYOTA hand-held tester to the DLC3.
2. Turn the ignition switch ON.
3. Turn the TOYOTA hand-held tester main switch ON.
4. Select the ACTIVE TEST mode on the TOYOTA hand-held tester to operate the VSV for canister closed valve (CCV).
NOTE: Do not start the engine.
HINT: If the check is not completed within 10 minutes when the VSV for canister closed valve (CCV) is ON, the forced closure of the VSV for CCV will be reset.
l. If you do not have the TOYOTA hand-held tester:
Force the VSV for CCV to operate.
1. Disconnect the VSV for CCV connector.
2. Connect the positive (+) and negative (-) leads from the battery to the VSV for CCV terminals.
m. Check the pressure.
1. Increase the pressure (13.5 - 15.5 in.H2O) from the EVAP service port.
Pressure: 2 minutes after the pressure has been increased, the gauge should indicate a value between 7.7 and 8.8 in.H2O.
HINT: If pressure cannot be increased, it can be concluded that the hose connecting the VSV for the EVAP canister fuel tank has slipped off or the VSV is open.
2. Check if the pressure decreases when the fuel tank cap is removed while increasing pressure.
HINT: If the pressure does not decrease when the fuel tank cap is removed, then it can be concluded that the hose connecting the service port to the fuel tank is blocked, etc.
n. If you have the TOYOTA hand-held tester: Conclude forced driving of the VSV for canister closed valve (CCV).
1. Turn ignition switch OFF.
2. Disconnect the TOYOTA hand-held tester from the DLC3.
o. If you do not have the TOYOTA hand-held tester:
1. Disconnect the positive (+) and negative (-) leads from the VSV for CCV terminals.
2. Reconnect the VSV for CCV connector.
p. Disconnect the pressure gauge from the EVAP service port on the purge line.
5. CHECK AIRTIGHTNESS IN FUEL TANK AND FILLER PIPE
a. Disconnect the EVAP line hose from the charcoal canister.
1. Pinch part A.
2. Pull out the connector.
b. Pressurize the internal pressure in the fuel tank to 4 kPa (41 gf/sq.cm, 0.58 psi).
c. Check that the internal pressure of the fuel tank can be maintained for 1 minute.
d. Check the connected parts of each hose and pipe.
e. Check the installed parts on the fuel tank and filler pipe.
If there is no abnormality, replace the fuel tank and filler pipe.
f. Reconnect the EVAP line hose to the charcoal canister.
6. INSPECT FUEL CUT OFF VALVE AND FILL CHECK VALVE
a. Disconnect the purge line hose, EVAP line hose and air inlet hose from the charcoal canister.
b. Hold the air inlet port.
c. Pressurize 4 kPa (41 gf/sq.cm, 0.58 psi) to the purge port and check that there is ventilation through the EVAP line hose.
HINT: Check the fuel volume in the fuel tank if there is no ventilation in step (c). If the fuel tank is full, the EVAP line vent is closed by a float valve of the fill check valve, preventing air from passing through the EVAP line hose. Reduce the fuel volume if necessary.
d. Check that the vent line hose and the EVAP line hose are not clogged up.
If they are clogged up, replace the fuel cut off valve and fill the check valve.
e. Reconnect the purge line hose and EVAP line hose to the charcoal canister.
7. CHECK AIR INLET LINE
a. Disconnect the air inlet line hose from the charcoal canister.
b. Check that there is ventilation in the air inlet line.
c. Reconnect the air inlet line hose to the charcoal canister.
8. REMOVE CHARCOAL CANISTER
a. Disconnect the connector.
b. Disconnect the 2 fuel tank vent hoses.
1. Push the connector fully inside.
2. Pinch part A.
3. Pull out the connector.
c. Disconnect the purge hose.
d. Pinch the fuel tube connector clip and then pull out the fuel emission tube.
NOTE:
- Check around the connector for dirt or mud before performing the operation and remove dirt if necessary.
- Check the quick connector O-ring for mud, as it may have caused contamination to the pipe and connector.
- Do not use any tool during the operation.
- Do not bend or twist the nylon tube. Protect the connector by covering it with a vinyl or plastic bag.
- When the pipe and connector are stuck, push and pull the connector to release and pull the connector out carefully.
e. Remove the 3 bolts and charcoal canister.
9. INSPECT CHARCOAL CANISTER
a. Visually check the charcoal canister for cracks or damage.
b. Inspect the charcoal canister operation.
1. Plug the vent port with a cap.
2. While holding the purge port closed, blow air (1.76 kPa, 18 gf/sq.cm, 0.26 psi) into the EVAP port and check that air flows from the air inlet port.
3. Plug the air inlet port with your finger.
4. Apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg), check that the vacuum decreases when the air inlet port is opened.
5. While holding the air inlet port closed, apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg) to the EVAP port and check that air flows into the purge port.
If a problem is found, replace the charcoal canister.
6. Remove the cap from the vent port.
c. Inspect the VSV for open circuit.
1. Using an Ohmmeter, check the resistance between the terminals.
If the resistance is not as specified, replace the VSV.
d. Inspect the VSV for ground.
1. Using an ohmmeter, check that there is no continuity between each terminal and the body.
If there is continuity, replace the VSV.
e. Inspect VSV operation.
1. Check that air flows from port A to port B.
2. Apply battery positive voltage across the terminals.
3. Check that air does not flow from port A to port B. If operation is not as specified, replace the VSV.
10. INSPECT DUTY VACUUM SWITCHING VALVE
a. Inspect the VSV for open circuit.
1. Using an ohmmeter, check that there is continuity between the terminals.
Resistance: 30 to 34 Ohm @ 20 °C (68 °F)
If the resistance is not as specified, replace the VSV.
b. Inspect the VSV for ground.
1. Using an ohmmeter, check that there is no continuity between each terminal and the body.
If there is continuity, replace the VSV.
c. Inspect VSV operation.
1. Check that air flow is not smooth with difficulty from port F to port E.
2. Apply battery voltage across the terminals.
3. Check that air flows from port F to port E.
If operation is not as specified, replace the VSV.
11. INSTALL CHARCOAL CANISTER
a. Install the charcoal canister with 3 bolts.
Torque: 19 Nm (193 kgf.cm, 14 ft.lbf)
b. Connect the fuel emission tube.
c. Connect the purge hose.
d. Connect the 2 fuel tank vent hoses.
e. Connect the connector.