Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. VISUALLY CHECK HOSES, CONNECTIONS AND GASKETS

(a) Visually check that the hoses, connections and gaskets have no cracks, leaks or damage.

NOTICE:

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

If any defects are found, replace parts as necessary.

2. INSPECT EVAPORATIVE EMISSION CONTROL SYSTEM

CAUTION:

To prevent injury due to contact with an operating cooling fan, keep your hands and clothing away from the cooling fans when working in the engine compartment with the engine running or the power switch on (IG).

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Put the engine in Inspection Mode (Maintenance Mode).

(e) Disconnect the No. 1 fuel vapor feed hose from the purge valve (purge VSV).

(f) Enter the following menus: Powertrain / Engine / Active Test / Activate the EVAP Purge VSV.

(g) Check that vacuum occurs at the purge valve (purge VSV) port.

(h) If vacuum does not occur, check the following items.

• Purge valve (purge VSV)
• Clogging in the No. 2 fuel vapor feed hose that connects the intake manifold and purge valve (purge VSV)
• Voltage from the ECM PRG terminal

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(i) Exit Active Test mode and connect the No. 1 fuel vapor feed hose.

If the result is not as specified, replace the purge valve (purge VSV), wire harness or ECM.

(j) Enter the following menus: Powertrain / Engine / Data List / EVAP (Purge) VSV.

(k) Warm up the engine and drive the vehicle.

(l) Confirm that the purge valve (purge VSV) opens.

If the result is not as specified, replace the purge valve (purge VSV), wire harness or ECM.

3. CHECK FUEL TANK AND VENT LINE

(a) Disconnect the fuel tank vent hose sub-assembly from the fuel vapor containment valve (fuel tank solenoid main valve assembly).

(b) Connect a pressure gauge to the fuel tank vent hose sub-assembly.

(c) Apply 4 kPa (0.04 kgf/cm2, 0.6 psi) of pressure to the vent line of the fuel tank assembly.

HINT:

Perform this inspection with the fuel tank assembly less than 90% full. When the fuel tank assembly is full, the fuel fill check valve closes and the pressure is released through the 2 mm (0.0787 in.) orifice. As a result, when the fuel tank cap assembly is removed, the pressure does not decrease smoothly.

(d) Check that the fuel tank assembly pressure is maintained for some time and does not decrease immediately.

HINT:

If the pressure decreases immediately, one of the following may apply:

• The fuel tank cap assembly is not completely tightened.
• The fuel tank cap assembly is damaged.
• Air is leaking from the vent line.
• The fuel tank assembly is damaged.

(e) Remove the fuel tank cap assembly and check that the pressure is released smoothly.

If the pressure is not released smoothly, replace the fuel tank assembly.

(f) Connect the fuel tank vent hose sub-assembly to the fuel vapor containment valve (fuel tank solenoid main valve assembly).

4. INSPECT AIR LINE

(a) Disconnect the fuel tank vent hose sub-assembly from the leak detection pump sub-assembly.

*1 Fuel Tank Vent Hose Sub-assembly *a Air

(b) Check that air flows freely into the air line.

If air does not flow freely into the air line, repair or replace the fuel tank vent hose sub-assembly.

(c) Connect the fuel tank vent hose sub-assembly to the leak detection pump sub-assembly.