Emission Control System (3MZ-FE): Inspection

INSPECT VENTILATION VALVE SUB-ASSY
1. Check the operation.
  1. Install a clean hose as shown in the illustration.
  2. Blow air into the cylinder head side, then check that air passes through easily.
  CAUTION: Do not suck air through the ventilation valve. Petroleum substances inside the ventilation valve are harmful.
  
  Fig 1: Cross Sectional View Of Ventilation Valve Sub Assembly (Cylinder Head Side)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Blow air into the intake manifold side, then check that air passes through with difficulty.
If the operation is not as specified, replace the ventilation valve.

Fig 2: Cross Section View Of Ventilation Sub Assembly (Intake Manifold Side)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT FUEL TANK CAP ASSY
1. Check the appearance.
  1. Visually check if the fuel tank cap and gasket are deformed or damaged.
If necessary, replace the fuel tank cap.

Fig 3: Inspecting Fuel Cap & Gasket (Visually)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT CHARCOAL CANISTER ASSY

Check the appearance.
1. Visually check the charcoal canister to see if the indicated portions by the arrows are cracked or damaged.
If necessary, replace the charcoal canister.

Fig 4: Inspecting Charcoal Canister For Damage (Visually)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Check the operation.
1. While holding the purge port closed, blow air (0.39 kPa (4.0 gf/cm² , 0.06 psi)) into the vent port, then check that the air flows from the air inlet port.
  If the operation is not as specified, replace the charcoal canister.
  
  Fig 5: Checking Operation By Closing Air Inlet Port
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. While holding the air inlet port closed, blow air (0.39 kPa (4.0 gf/cm² , 0.06 psi)) into the vent port, then check that the air flows from the purge port.
  If the operation is not as specified, replace the charcoal canister.
  
  Fig 6: Checking Operation By Closing Air Inlet Port
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. While holding the air inlet port closed, apply vacuum (3.43 kPa (25.7 mm/Hg, 1.01 in.Hg)) to the vent port, then check that the air is sucked from the purge port.
  If the operation is not as specified, replace the charcoal canister.
Fig 7: Checking Operation By Closing Air Inlet Port & Applying Vacuum
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Check the air tightness.
1. While holding the vent and air inlet ports closed, apply vacuum (3.43 kPa (25.7 mmHg, 1.01 in.Hg)) to the purge port, then check that the vacuum is maintained for 1 minute.
HINT:

In order to maintain air tightness, the check should be performed with the VSV (for CCV) terminal port held closed by your finger.

If the operation is not as specified, replace the charcoal canister.

Fig 8: Checking Air Tightness By Closing Air Inlet Port & Applying Vacuum
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Inspect the diaphragm.
1. Remove the air hose.
  
  Fig 9: Removing Air Hose
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. While holding the vent, purge and air inlet ports closed, apply vacuum (1.42 kPa (11 mmHg, 0.42 in.Hg)) into port A, then check that the air is sucked from port B.
  If the operation is not as specified, replace the charcoal canister.
  
  Fig 10: Checking Operation By Closing Vent, Port & Air Inlet Ports
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. While holding the vent, purge and air inlet ports closed, apply vacuum (1.42 kPa (11 mmHg, 0.42 in.Hg)) into port A, then measure how long it takes for vacuum to drop.
  Vacuum drop time: 10 seconds or longer
  
  If the operation is not as specified, replace the charcoal canister.
4. Reinstall the air hose.
Fig 11: Checking Operation By Applying Vacuum & Closing Ports
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the air hose.
Remove the 2 bolts, then remove the VSV.

Fig 12: Removing VSV
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Inspect the resistance.

(1)Using an ohmmeter, measure the resistance between the terminals.

Standard:

TERMINALS RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
1 - 2	25 to 30 Ω at 20°C (68°F)
1 - 2	32 to 40 Ω at 100°C (212°F)

If the resistance is not as specified, replace the charcoal canister.

Fig 13: Measuring Resistance Between Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the operation.
1. Check that air flows from port A to B and C.
  
  Fig 14: Checking Air Flows From Port A To B & C
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Apply battery voltage across the terminals.
3. Check that the valve is closed.
  
  Fig 15: Checking For Valve Closed By Applying Battery Voltage
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Check that air does not flow from port A to B.
5. Check that air flows from port A to C.
If the operation is not as specified, replace the charcoal canister.
Install the VSV with the 2 bolts.
Connect the air hose.

Fig 16: Checking Air Flows From A To C

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT VACUUM SWITCHING VALVE ASSY NO.1

Inspect the resistance.

Using an ohmmeter, measure the resistance between the terminals.

Standard:

TERMINALS RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
1 - 2	26 to 30 Ω at 20°C (68°F)

If the resistance is not as specified, replace the vacuum switching valve No. 1.

Fig 17: Measuring Resistance Between Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the operation.
1. Check that air does not flow from port E to F.
  
  Fig 18: Checking Air Does Not Flow From Port E To F
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Apply battery voltage across the terminals.
3. Check that air flows from port E to F.
If the operation is not as specified, replace the vacuum switching valve No.1.

Fig 19: Checking Air Flow From Port E To F
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT AIR FUEL RATIO SENSOR

Inspect the resistance.

Using an ohmmeter, measure the resistance between the terminals.

Standard:

TERMINALS RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
1 (HT) - 2 (+B)	1.8 to 3.4 Ω at 20°C (68°F)

If the resistance is not as specified, replace the air fuel ratio sensor.

Fig 20: Measuring Resistance Between Air Fuel Ratio Sensor Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the continuity.
1. Using an ohmmeter, check that there is no continuity between terminals 2 (+B) and 4 (AF-).

If there is continuity, replace the air fuel ratio sensor.

INSPECT HEATED OXYGEN SENSOR

Inspect the resistance.

Using an ohmmeter, measure the resistance between the terminals.

Standard:

TERMINALS RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
1 (HT) - 2 (+B)	11 to 16 Ω at 20°C (68°F)

If the resistance is not as specified, replace the heated oxygen sensor.

Check the continuity.
1. Using an ohmmeter, check that there is no continuity between terminals 1 (HT) and 4 (E).
If there is continuity, replace the heated oxygen sensor.

Fig 21: Measuring Resistance Between Heated Oxygen Sensor Terminals

INSPECT AIR FUEL RATIO SENSOR HEATER RELAY

Inspect the resistance.

Using an ohmmeter, measure the resistance between the terminals.

Standard:

TERMINALS RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
3-5	10 kΩ or higher
3 - 5	Below 1° (Apply battery voltage to terminals 1 and 2

If the result is not as specified, replace the air fuel ratio sensor heater relay.

Fig 22: Measuring Resistance Between Air Fuel Ratio Sensor Heater Relay Terminals