On-Vehicle Inspection
ON-VEHICLE INSPECTION1. INSPECT AIR-FUEL RATIO COMPENSATION SYSTEM
a. Measure the voltage between the terminals of the ECM connectors.
NOTE: Connect test leads from the back side of the connector. The connectors should not be disconnected from the ECM.
HINT: Voltage between the terminals of the ECM is kept constant regardless of the voltage of the A/F sensor.
b. Connect the hand-held tester to the DLC3.
c. Turn the ignition switch to ON.
d. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / A/FS B1 S1 and O2S B1S2.
e. Warm up the A/F sensor with the engine speed at 2,500 rpm for approximately 2 minutes.
f. Keep the engine speed at 2,500 rpm and confirm that the display, when A/FS B1 S1 is selected, is as shown in the illustration.
HINT:
- The illustration may slightly differ from the display on the hand-held tester.
- Only the hand-held tester displays the waveform of the A/F sensor.
g. Confirm that the display, when O2S B1 S2 is selected, changes between 0 V and 1 V with the engine speed at 2,500 rpm.
OK:
The voltage output oscillates more than 8 times in 10 seconds.
CAUTION:
- Perform the check immediately after warming up the engine.
- If the voltage variation could not be verified, warm up the heated oxygen sensor again. If it could not be verified even after warming up the sensor again, check the DTC No.
2. INSPECT FUEL CUT OFF RPM
a. Increase the engine speed to at least 3,500 rpm.
b. Use a sound scope to check for injector operating sounds.
c. Check that injector operating sounds stop momentarily and then resume when the accelerator pedal is released.
Fuel cut off rpm: 2,500 rpm
Fuel return rpm: 1,200 rpm
3. VISUALLY INSPECT HOSES, CONNECTIONS AND GASKETS
a. Check the appearance.
1. Check if the indicated portions of the engine assembly are cracked, leaking or damaged.
HINT: Disconnection of the engine oil level gauge, oil filler cap, PCV hose, etc. may cause the engine to run improperly. Disconnection, slack or cracks in the air induction system parts between the throttle body and cylinder head will allow air suction and cause the engine to run improperly.
If necessary, repair the engine assembly.
4. INSPECT EVAP SYSTEM LINE
a. Warm up the engine and then 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 a hand-held tester:
Operate the VSV of EVAP using a hand-held tester.
1. Connect the hand-held tester to the DLC3.
2. Start the engine.
3. Turn the hand-held tester ON.
4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II/ ACTIVE TEST / EVAP VSV (ALONE).
d. When not using a hand-held tester:
Operate the VSV of EVAP not using a hand-held tester.
1. Disconnect the VSV for EVAP connector.
2. Connect the positive (+) and negative (-) leads of the battery to the VSV for EVAP terminals.
3. Start the engine.
e. Check the vacuum while the engine idles.
Vacuum:
Maintain 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 VSV to the service port is loose or blocked, or the VSV is malfunctioning.
f. When using a hand-held tester:
Conclude the operation of the VSV of EVAP using a hand-held tester.
1. Stop the engine.
2. Disconnect the hand-held tester from the DLC3.
g. When not using a hand-held tester:
Conclude the operation of the VSV of EVAP not using a hand-held tester.
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. Pinch the rubber hose with the clip to prevent air entering into the canister passage.
2. Apply pressure (13.5 to 15.5 in.Aq) from the EVAP service port.
Pressure:
The gauge should still read over 7.7 to 8.8 in.Aq for 2 minutes after the pressure is applied.
HINT: If air cannot be applied, the hose connecting the VSV-canister-fuel tank has slipped off or the VSV is open.
3. Check whether 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.
5. INSPECT FUEL CUTOFF VALVE AND FILL CHECK VALVE
a. Remove the fuel tank.
b. Connect the pressure gauge to the vent hose port.
c. Install the fuel tank with the vent hose disconnected.
d. Fill the fuel tank with fuel.
e. 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.
f. Remove the fuel tank cap, and check that the pressure drops.
If the pressure does not drop, replace the fuel tank assembly.
g. 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. 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.